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All knowledge of biology I have comes from online and after speaking for a brief period of time with someone from a biological education it is very clear that I have no knowledge of the pronunciation of all the necessary jargon I have learnt.
For example: Chordae Tendineae, Squamous Suture, Loop of Henle
How have people overcome this issue? I have searched online for pronunciation videos and whatnot, but very often they pronounce them differently to each other and it is impossible to know who is correct. I also do not want to learn the IPA for English.
I would try to use the audio features of dictionaries on the internet.
Ideally you would buy a good scientific dictionary app with audio pronunciation for your iPhone, just as I have for foreign language dictionaries on mine. However, the scientific offerings I found on the app store did not fit the bill (there may be something hiding there that I missed), so I looked on the web, and what I found was:
The Science Dictionary
Now this appears not to be an actual dictionary itself, but an aggregating site. So when I searched for Chordae I got several options, mainly from Wikipedia, which did not provide audio pronunciation, but also from
which did - for both the singular (which is what is the listing) and the plural.
Dictionary.com doesn't always provide audio pronunciations. When I tried squamous suture there was only a definition - but there were individual pronunciations for squamous and suture.
(Loop of Henle was also there with pronunciation. Perhaps going directly to dictionary.com is your best bet.)
Rider and caveat
As @JM97 mentioned in a comment, some entries in the free dictionary have audio pronunciation, although others do not. There may be other on-line facilities that do likewise. However with any on-line dictionary one should ask oneself how reliable is the pronunciation; and it is difficult to tell because one doesn't know how it is done in the way one does with a primary dictionary with a print reputation.
For example, take the pronunciation of the word "caeca". The open dictionary pronounces this in a classical Latin style with a hard C, whereas dictionary.com. pronounces it in a mediaeval Latin style with a soft C, the way it is pronounced by scientists I know who dissect it.
It is also worth noting that in my experience, "accepted" pronunciation may vary quite a bit between biological disciplines and who a given specialist might have learned it from! For terms stolen directly from Latin, for example, there is often considerable variation between people about whether they should be pronounced in a Classical Latin style, an ecclesiastical/medieval Latin style, or (most commonly) an Anglicized style that sounds about right to an English-speaking biologist.
Names like the Loop of Henle are also tricky because they require you to know that they're anatomical structures named for particular people (in this case, Friedrich Gustav Jakob Henle), work out what language the person's last name is from, and then guess at what it is for an English speaker. English speakers do not always get this "right" on the first go, and weird pronunciations not infrequently result from confusions like this.
Personally, I wouldn't worry too much about it--I might just run pronunciations by a friend first and check to make sure I have them right there if I felt embarrassed.
Below is a list of a few biology words and terms that many biology students find difficult to understand. By breaking these words down into discrete units, even the most complex terms can be understood.
This word can be separated as follows: Auto - troph.
Auto - means self, troph - means nourish. Autotrophs are organisms capable of self-nourishment.
This word can be separated as follows: Cyto - kinesis.
Cyto - means cell, kinesis - means movement. Cytokinesis refers to the movement of the cytoplasm that produces distinct daughter cells during cell division.
This word can be separated as follows: Eu - karyo - te.
Eu - means true, karyo - means nucleus. A eukaryote is an organism whose cells contain a "true" membrane-bound nucleus.
This word can be separated as follows: Hetero - zyg - ous.
Hetero - means different, zyg - means yolk or union, ous - means characterized by or full of. Heterozygous refers to a union characterized by the joining of two different alleles for a given trait.
This word can be separated as follows: Hydro - philic.
Hydro - refers to water, philic - means love. Hydrophilic means water-loving.
This word can be separated as follows: Oligo - saccharide.
Oligo - means few or little, saccharide - means sugar. An oligosaccharide is a carbohydrate that contains a small number of component sugars.
This word can be separated as follows: Osteo - blast.
Osteo - means bone, blast - means bud or germ (early form of an organism). An osteoblast is a cell from which bone is derived.
This word can be separated as follows: Teg - ment - um.
Teg - means cover, ment - refers to mind or brain. The tegmentum is the bundle of fibers that cover the brain.
- To be successful in the sciences, particularly in biology, one must understand the terminology.
- Common affixes (prefixes and suffixes) that are used in biology are often derived from Latin and Greek roots.
- These affixes form the basis for many difficult biology words.
- By breaking these difficult terms down into their formative units, even the most complex biological words can be easily understood.
From the Editors at Merriam-Webster
'Vaxication': All I Ever Wanted
'Vaxication': All I Ever Wanted
For those who get the shot and go.
The Words of the Week - 11/13/20
The Words of the Week - 11/13/20
Some of the words that defined the week ending November 13, 2020
The Good, The Bad, & The Semantically Imprecise - 3/22/19
The words that defined the week of March 22nd, 2019
Glossary of biology
This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices for more specific and technical definitions from sub-disciplines and related fields, see Glossary of genetics, Glossary of evolutionary biology, Glossary of ecology, and Glossary of scientific naming, or any of the organism-specific glossaries in Category:Glossaries of biology.
Any member of a diverse polyphyletic group of photosynthetic , eukaryotic , mostly aquatic organisms ranging from simple unicellular microalgae to massive colonial or multicellular forms such as kelp. Algae may reproduce sexually or asexually , and are often compared to plants , though they lack most of the complex cell and tissue types that characterize true plants. A form of speciation which occurs when biological populations of the same species become isolated from each other to an extent that prevents or interferes with genetic interchange. A class of organic compounds containing an amine group and a carboxylic acid group which function as the fundamental building blocks of proteins and play important roles in many other biochemical processes. An organism which produces an egg composed of a shell and membranes that creates a protected environment in which the embryo can develop outside of water. A set of morphological structures in different organisms which have similar form or function but were not present in the organisms' last common ancestor . The cladistic term for the same phenomenon is homoplasy. The branch of biology that studies the structure and morphology of living organisms and their various parts. Any member of a clade of multicellular eukaryotic organisms belonging to the biological kingdom Animalia. With few exceptions, animals consume organic material , breathe oxygen , are able to move , reproduce sexually , and grow from a blastula during embryonic development. An estimated 7 million distinct animal species currently exist.
Also called an antibacterial.
A type of antimicrobial drug used in the treatment and prevention of bacterial infections . A highly regulated form of programmed cell death that occurs in multicellular organisms. The scientific study of spiders, scorpions, pseudoscorpions, and harvestmen, collectively called arachnids.
Also called selective breeding.
The process by which humans use animal breeding and plant breeding to selectively control the development of particular phenotypic traits in organisms by choosing which individual organisms will reproduce and create offspring . While the deliberate exploitation of knowledge about genetics and reproductive biology in the hope of producing desirable characteristics is widely practiced in agriculture and experimental biology, artificial selection may also be unintentional and may produce unintended (desirable or undesirable) results. A type of reproduction involving a single parent that results in offspring that are genetically identical to the parent. The branch of biology concerned with the effects of outer space on living organisms and the search for extraterrestrial life. The system of immune responses of an organism directed against its own healthy cells and tissues.
Sometimes used interchangeably with primary producer .
An organism capable of producing complex organic compounds from simple substances present in its surroundings, generally by using energy from sunlight (as in photosynthesis ) or from inorganic chemical reactions (as in chemosynthesis ). Autotrophs do not need to consume another living organism in order to obtain energy or organic carbon, as opposed to heterotrophs .
Also called the biosynthetic phase, light-independent reactions, dark reactions, or photosynthetic carbon reduction (PCR) cycle.
A series of chemical reactions which occurs as one of two primary phases of photosynthesis , specifically the phase in which carbon dioxide and other compounds are converted into simple carbohydrates such as glucose. These reactions occur in the stroma, the fluid-filled area of the chloroplast outside the thylakoid membranes. In the Calvin cycle, the products of previous light-dependent reactions ( ATP and NADPH ) undergo further reactions which do not require the presence of light and which can be broadly divided into three stages: carbon fixation , reduction reactions, and ribulose 1,5-bisphosphate (RuBP) regeneration. 
Also called carbon assimilation.
The process by which inorganic carbon, particularly in the form of carbon dioxide, is converted to organic compounds by living organisms. Examples include photosynthesis and chemosynthesis . Any member of two classes of chemical compounds derived from carbonic acid or carbon dioxide. One of a class of organic pigments produced by algae and plants , as well as certain bacteria and fungi . An enzyme found in nearly all living organisms exposed to oxygen, including bacteria , plants , and animals . The basic structural and functional unit of all living organisms , and the smallest functional unit of life . A cell may exist as an independent, self-replicating unit (as in the case of unicellular organisms ), or in cooperation with other cells, each of which may be specialized for carrying out particular functions within a larger multicellular organism . Cells consist of cytoplasm enclosed within a cell membrane and sometimes a cell wall , and serve the fundamental purpose of separating the controlled environment in which biochemical processes take place from the outside world. Most cells are visible only under a microscope.
Also called cytology.
The branch of biology that studies the structure and function of living cells , including their physiological properties, metabolic processes, chemical composition, life cycle , the organelles they contain, and their interactions with their environment. This is done at both microscopic and molecular levels. The ordered series of events which take place in a cell leading to duplication of its genetic material and ultimately the division of the cytoplasm and organelles to produce two or more daughter cells. These events can be broadly divided into phases of growth and division, each of which can vary in duration and complexity depending on the tissue or organism to which the cell belongs. Cell cycles are essential processes in all unicellular and multicellular organisms. Any process by which a parent cell divides into two or more daughter cells. Examples include binary fission , mitosis , and meiosis . The semipermeable membrane surrounding the cytoplasm of a cell . The "control room" for the cell . The nucleus gives out all the orders. Grown in the cell's center, it fuses with the parental plasma membrane, creating a new cell wall that enables cell division . The theory that all living things are made up of cells . A tough, often rigid structural barrier surrounding certain types of cells (such as in fungi , plants , and most prokaryotes ) that is immediately external to the cell membrane . Of or relating to a cell . A framework for understanding the movement of genetic information between information-carrying biopolymers within biological systems. Popularly (though simplistically) stated as " DNA makes RNA and RNA makes protein ", the principle attempts to capture the notion that the transfer of genetic information only naturally occurs between certain classes of molecules and in certain directions. A cylindrical cell structure found in most eukaryotic cells, composed mainly of a protein called tubulin. An organelle that is the primary site at which microtubules are organized. They occur only in plant and animal cells and help to regulate cell division . A chemical substance consisting of two or more different chemically bonded elements, with a fixed ratio determining the composition. The ratio of each element is usually expressed by a chemical formula. The state in which both reactants and products are present in concentrations which have no further tendency to change with time in a chemical reaction. A process that leads to the transformation of one set of chemical substances to another. A branch of the physical sciences that studies the composition, structure, properties, and change of matter. Chemical interactions underlie all biological processes. Any of several photosynthetic pigments found in cyanobacteria, algae , or plants . A type of highly specialized organelle in the cells of plants and algae , the main role of which is to conduct photosynthesis , by which the photosynthetic pigment chlorophyll captures the energy from sunlight and converts and stores it in the molecules ATP and NADPH while freeing oxygen from water. A type of lipid molecule that is biosynthesized by all animal cells because it is an essential structural component of animal cell membranes , essential for maintaining both membrane structural integrity and fluidity. A threadlike strand of DNA in the cell nucleus that carries the genes in a linear order.
Also called the Krebs cycle and tricarboxylic acid cycle (TCA).
A series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetyl-CoA derived from carbohydrates , fats , and proteins into carbon dioxide and chemical energy in the form of guanosine triphosphate (GTP). In addition, the cycle provides the chemical precursors for certain amino acids as well as the reducing agent NADH that is used in numerous other biochemical reactions. Its central importance to many biochemical pathways suggests that it was one of the earliest established components of cellular metabolism and may have originated abiogenically. A scientific theory in immunology that explains the functions of cells (lymphocytes) of the immune system in response to specific antigens invading the body. The theory has become the widely accepted model for how the immune system responds to infection and how certain types of B and T lymphocytes are selected for destruction of specific antigens.  The process of producing individual organisms or molecules with identical or virtually identical DNA , either naturally or artificially. Many organisms, such as bacteria , insects, and plants , are capable of naturally producing clones through asexual reproduction . In biotechnology , cloning refers to the artificial creation of copies of cells, DNA fragments, or other biomolecules by various laboratory techniques. In the context of virus capsid, may refer colloquially to the defined geometric structure of a capsid, or the membrane of an endosome containing an intact virion. The coat of a virus is used in descriptions for the general public. Related slang: uncoating. The use of comparative methods to study the similarities and differences between two or more biological organisms (e.g. two organisms from the same time period but different taxa , or two organisms from the same taxon but different times in evolutionary history). The side-by-side comparison of morphological or molecular characteristics of different organisms is the basis from which biologists infer the organisms' genetic relatedness and their natural histories. It is a fundamental tool in many biological disciplines, including anatomy, physiology, paleontology , and phylogenetics . The scientific study of nature and of Earth's biodiversity with the aim of protecting species , their habitats , and ecosystems from excessive rates of extinction and the erosion of biotic interactions. An evolutionary process by which species of different lineages independently develop similar characteristics, often to the point that the species appear to be more closely related than they actually are. The crossover of some property, usually heat or some component, between two fluids flowing in opposite directions to each other. The phenomenon occurs naturally but is also frequently mimicked in industry and engineering. A fold in the inner membrane of a mitochondrion . The branch of biology that studies the effects of low temperatures on living things within Earth's cryosphere or in laboratory experiments. See cell biology . All of the material within a cell and enclosed by the cell membrane , except for the nucleus . The cytoplasm consists mainly of water, the gel-like cytosol, various organelles , and free-floating granules of nutrients and other biomolecules . One of the four main nitrogenous bases found in both DNA and RNA , along with adenine , guanine , thymine , and uracil (in RNA) it is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at position 2). A complex, dynamic network of interlinking protein filaments that extends from the cell nucleus to the cell membrane and which is present in the cytoplasm of all cells , including bacteria and archaea .  The cytoskeletal systems of different organisms are composed of similar proteins. In eukaryotes, the cytoskeletal matrix is a dynamic structure composed of three main proteins, which are capable of rapid growth or disassembly dependent on the cell's requirements. 
Also called the macula adhaerens.
A cell structure specialized for cell-to-cell adhesion. The branch of biology that studies the processes by which living organisms grow and develop over time. The field may also encompass the study of reproduction , regeneration , metamorphosis , and the growth and differentiation of stem cells in mature tissues. Any particular abnormal condition that negatively affects the structure or function of all or part of a living organism and that is not the result of any immediate external injury. Diseases are medical conditions that are often identifiable by specific signs and symptoms. They may be caused by external factors such as infectious pathogens or by internal dysfunctions such as immune deficiency or senescence . See deoxyribonucleic acid . The chemical duplication or copying of a DNA molecule the process of producing two identical copies from one original DNA molecule, in which the double helix is unwound and each strand acts as a template for the next strand. Complementary nucleotide bases are matched to synthesize the new partner strands. The process of determining the precise order of nucleotides within a DNA molecule. Any substance that causes a change in an organism's physiology or psychology when consumed. Drugs may be naturally occurring or artificially produced, and consumption may occur in a number of different ways. Drugs are typically distinguished from substances that provide nutritional support such as food. The existence of a morphological distinction between organisms of the same species , such that individuals of that species occur in one of two distinct forms which differ in one or more characteristics, such as colour, size, shape, or any other phenotypic trait. Dimorphism based on sex – e.g. male vs. female – is common in sexually reproducing organisms such as plants and animals. A motor protein in cells which converts the chemical energy contained in ATP into the mechanical energy of movement.
Also called a trophic pyramid, eltonian pyramid, energy pyramid, or sometimes food pyramid.
A graphical representation of the biomass or bio-productivity generated at each trophic level in a given ecosystem . The more or less predictable and orderly set of changes that occurs in the composition or structure of an ecological community over time. The scientific analysis and study of interactions between organisms and their environment . It is an interdisciplinary field that combines concepts from biology, geography, and Earth science. A biological discipline that studies the adaptation of an organism's physiology to environmental conditions. A community of living organisms in conjunction with the non-living components of their physical environment, interacting as a system.
Sometimes called an ecospecies.
In evolutionary ecology, a genetically distinct geographic variety, population , or race within a species which is adapted to specific environmental conditions. The outermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the epidermis, nerve tissue, and nephridia. An organism in which internal physiological sources of heat are of relatively small or quite negligible importance in controlling body temperature compared to ambient sources of heat. Ectotherms generally experience changes in body temperature that closely match changes in the temperature of their environment colloquially, these organisms are often referred to as "cold-blooded". Contrast endotherm . A small molecule that selectively binds to a protein and regulates its biological activity. In this manner, effector molecules act as ligands that can increase or decrease enzyme activity, gene expression, or cell signaling. Conducted or conducting outwards or away from something (for nerves, the central nervous system for blood vessels, the organ supplied). Contrast afferent . The organic vessel containing the zygote in which an animal embryo develops until it can survive on its own, at which point the developing organism emerges from the egg in a process known as hatching. A gradient of electrochemical potential, usually for an ion that can move across a membrane . The gradient consists of two parts: the electrical potential and the difference in chemical concentration across the membrane. Any chemical entity that accepts electrons transferred to it from another chemical entity. It is an oxidizing agent that, by virtue of its accepting electrons, is itself reduced in the process. Contrast electron donor . Any of various molecules that are capable of accepting one or two electrons from one molecule and donating them to another in the process of electron transport . As the electrons are transferred from one electron carrier to another, their energy level decreases, and energy is released. A chemical entity that donates electrons to another chemical entity. It is a reducing agent that, by virtue of its giving up its electrons, is itself oxidized in the process. Contrast electron acceptor . A type of microscope that uses a beam of electrons to create an image of a sample or specimen. Electron microscopes are capable of much higher magnifications and have greater resolving power than conventional light microscopes, allowing them to see much smaller objects in finer detail. The process of oxidative phosphorylation, by which the NADH and succinate generated by the citric acid cycle are oxidized and electrons are transferred sequentially down a long series of proteins , ultimately to the enzyme ATP synthase, which uses the electrical energy to catalyze the synthesis of ATP by the addition of a phosphate group to ADP. The process takes place in the cell's mitochondria and is the primary means of energy generation in most eukaryotic organisms. A developing stage of a multicellular organism . The branch of biology that studies the development of gametes (sex cells), fertilization, and development of embryos and fetuses . Additionally, embryology involves the study of congenital disorders that occur before birth. Any species which is very likely to become extinct in the near future, either worldwide or in a particular area. Such species may be threatened by factors such as habitat loss, hunting, disease, and climate change, and most have a declining population or a very limited range. The ecological state of an organism or species being unique to a defined geographic location, such as an island, nation, country, habitat type, or other defined zone. Organisms are said to be endemic to a place if they are indigenous to it and found nowhere else.
Also called a nonspontaneous reaction or unfavorable reaction.
A type of chemical reaction in which the standard change in free energy is positive, and energy is absorbed. A gland of the animalian endocrine system that secretes hormones directly into the blood rather than through a duct. In humans, the major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus, and adrenal glands. The collection of glands that produce hormones which regulate metabolism , growth and development, tissue function, and a wide variety of other biological processes. A form of active transport in which a cell transports molecules such as proteins into the cell's interior by engulfing them in an energy-consuming process. One of the three primary germ layers in the very early human embryo . The other two layers are the ectoderm (outside layer) and mesoderm (middle layer), with the endoderm being the innermost layer. (of a substance or process) Originating from within a system (such as an organism, tissue, or cell), as with endogenous cannabinoids and circadian rhythms . Contrast exogenous . A type of organelle found in eukaryotic cells that forms an interconnected network of flattened, membrane-enclosed sacs or tube-like structures known as cisternae. The tissue produced inside the seeds of most of the flowering plants following fertilization.
Botany Terms – Glossary of Botanical Terms
Following is the glossary of botanical terms and definitions with a complete compilation of botany terms for your reference.
Following is the glossary of botanical terms and definitions with a complete compilation of botany terms for your reference.
The study of plants and their related structures is what makes up the field of botany. Most plants are self-sufficient, autotrophic organisms. However, there are so many variations that are present even in plants, be it in their structure, size, color, or mode of nutrition. These numerous variations, in their phenotypic (outwardly visible) traits as well as their genotype, has made people study this group since centuries, thus, making botany one of the oldest sciences, rivaling astronomy today. Botany has formed the basis on which, the study of plants and consequently, living organisms was done. It was the plants present in his backyard that inspired Gregor Johann Mendel to propose the first laws of genetic inheritance, that are studied even to this day.
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The importance of this science cannot be stressed enough, as today, all living organisms owe their existence to plants, either directly or indirectly. If it weren’t for these green beings, we wouldn’t have had oxygen to breathe, nor fruits to eat!
Plants are of various types, ranging from edible with medicinal properties, to downright poisonous. It is this very study of plants that forms the crux of this intriguing and ever exploring science. So, here is the glossary of botanical terms and definitions with all the terms that normally ‘crop’ up during a detailed study of botany.
Abscisic Acid (ABA): A growth inhibiting hormone enabling perennial plants to tolerate stressful conditions by promoting dormancy, stomatal closure and inhibiting growth.
Abscission Zone: The zone at the base of the flower (pedicel), fruit (peduncle) or leaf (petioles), at which plant cells fray off, thereby facilitating the easy fall of these plant parts.
Absorption Spectrum: Graph indicating the relative abilities of pigments to absorb various wavelengths of light.
Acetyl CoA: Developed as an intermediate of carbohydrate/ fat/ protein oxidation in the citric acid cycle, Acetyle CoA is the aceylated form of coenzyme A.
Achene: A simple, single-seeded, dry, indehiscent fruit comprising one seed attached to only the base of the pericarp.
Active Transport: The forceful movement of molecules from one side of the plasma membrane to the other side against a diffusion gradient, by expenditure of energy.
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Adaptive Radiation: Diversification of group of organisms into several new species in order to fit into new environment.
Adenosine Diphoshate (ADP): A nucleotide comprising adenine, two phosphate units and ribose, it is a cofactor contributing either phosphate group or energy or both to a reaction.
Adenosine Triphoshate (ATP): A nucleotide comprising adenine, ribose and three phosphate units, is the major energy currency of the cell. It is a cofactor contributing phosphate group or energy or both to the reaction.
Adhesive Force: It is the force of attraction between dissimilar molecules due to which they stay together. For e.g. water droplets on a leaf.
Adventitious Roots: The roots that do not originate from primary roots are called adventitious. They generally arise from stems or leaves.
Aerobic Cellular Respiration: Part of cellular respiration, and plays a significant role in producing energy required to carry out different functions of the plant. It requires oxygen for the process.
Aerobic Respiration: Type of respiration requiring free oxygen as the terminal electron acceptor.
Agamospermy: Asexual reproduction methods involving cells of only the ovule to yield seeds and fruit.
Agar:A culture medium used specifically for bacteria. It is produced by some algae (red or brown) and has a gelatinous consistency.
Aggregate Fruit:The conjunction of several small, individual fruits, formed by different ovaries, located within the same flower to form a single fruit like that of raspberry.
Albuminous Seed: Seed containing large amounts of endosperm.
Allele: Gene versions varying from each other in their nucleotide sequence and may or may not result in different phenotypic traits.
Allopatric Speciation: Speciation emerging as the result of physical separation of two or more populations of one species, such that interbreeding is not possible.
Alternation of Generations: Plant life cycle type in sexually reproducing organisms involving alternation of diploid sporophyte phase and haploid gametophyte phase.
Amino Acid: Small molecule comprising nitrogen containing units used to synthesize proteins.
Anabolism: Process of metabolism by which various small molecules are combined to form large ones.
Anaerobic Respiration: Also called fermentation, this type of respiration does not need oxygen as the terminal electron acceptor.
Aneuploid: Anomaly in the usual chromosome number, wherein one or more chromosomes are missing or present as extras.
Angiosperm: Plants with seeds enclosed in ovaries that mature into a fruit.
Annual Ring: The formation of wood in plants on an annual basis comprises two concentric layers of wood: springwood and summerwood.
Anther: Part of the stamen containing sporogenous tissue which produces pollen.
Anthocyanin: Water soluble pigment located in the cell sap, which varies from red to blue in color. Found in flowers of most plants.
Apical Dominance: Hormones produced at the tip of the shoot cause suppression of lateral bud development in growing plant shoots.
Apical Deristem: Meristem located at the tip of the root, shoot or other organs of the plant.
Archegonium: Female reproductive organ in non-vascular plants like ferns and mosses.
Autotropic: Organisms converting inorganic matter into organic material for the purpose of sustenance.
Auxin: Growth regulating substance involved in apical dominance, cell elongation, rooting, etc.
Axil: Angle formed at the point of attachment between the petiole of a leaf and the upper part of the plant.
Axillary Bud: Bud situated just above the point of attachment of the leaf, i.e. leaf axil. Can be a floral bud or leaf bud.
Bacillus: Rod shaped, spore-producing bacteria belonging to the genus Bacillus.
Backcross: Cross between a hybrid and one of its parents.
Bacteria: Single celled, omnipresent organisms appearing in spiral, spherical or rod shape.
Bacteriophage: It is an obligate intracellular parasite that breed inside bacteria by using the host’s cellular machinery.
Bark: Tissues of the vascular cambium forming tough layer on the outer region of the woody stems and roots.
Base: Substances that reduce the concentration of hydrogen ions.
Basidiocarp: Fruiting body in basidiomycete fungi, such as puffball or mushroom.
Basidiospores: Spores formed on the basidium.
Basidium: The cells in basidiomycete fungi in which fusion of nuclei and meiosis occur to produce basidiospores.
Berry: Simple, thin-skinned fruit comprising a compound ovary with more than one seed, as in the case of gooseberry, grape, tomato, etc.
Biennial: Plants requiring two seasons to complete their life cycle. The first season growth is purely vegetative and the second one bears fruit.
Binary Fission: Process of cell division in prokaryotes, such as yeasts where the cell devides into two daughter cells.
Binomial Classification: System of classification that provides scientific names to organisms. Each name consists of a genus name and a species name.
Biological Controls: Use of natural inhibitors or enemies to combat pests and other damage causing organisms.
Biomass: Total mass of living matter present in a given habitat, expressed as volume of organisms per unit of habitat’s volume or weight per unit area.
Biotechnology: Use of living organisms, tissue or cells for the manufacture of drugs or products intended for human benefit.
Blade: The broad, flattened, conspicuous part of the lead called lamina that is distinguished from the petiole or stalk.
Bract: Leaf like structure situated at the base of the flower or inflorescence.
Bryophyte: Phylum comprising non-vascular plants: lacking xylem and phloem. Mosses, liverworts, etc are bryophytes.
Budding: Type of asexual reproduction involving formation of new cells from protrusions arising from mature cells. Yeast reproduces via budding.
Bundle Sheath: Layer of parenchyma or sclerenchyma cells encircling the vascular bundle in plant leaves and stems.
Callose: A plant polysaccharide composed of glucose residues linked together through β-1, 3-linkages secreted by an enzyme complex (callose synthase), resulting in the hardening or thickening of plant cell walls.
Callus: Tissue formed over damaged areas of the plant in the form of a seal, thereby protecting it from further deterioration, and allowing the wound to heal.
Calvin cycle: Biochemical reactions cycle occurring during photosynthesis in the chloroplasts, wherein carbon dioxide is fixed and 6 carbon sugar is formed.
Calyptra: Small sheath of cells found in non-vascular plants, derived from the archegonium to cover the tip of the capsule partially or completely.
Calyx: Collective terminology for the sepals of a flower.
Cambium: Layer of meristematic tissue (also known as lateral meristems), responsible for secondary growth.
Capillary Water: Water held in the tiny pores between soil particles by the adhesive force: surface tension.
Capsule: Dry, dehiscent fruit consisting of two or more carpels that splits in several ways at maturity to release seeds.
Carpel: Single member of a compound pistil or single pistil unit, bearing the ovule in angiosperms.
Caryopsis: Small, dry, single seeded fruits which do not split at maturity. The pericarp cleaves to the seed coat typically seen in grains.
Casparian Strip: Band of cell wall material in the radial and transverse walls of the endodermis. It stops the passive flow of materials into the stele.
Cation Exchange: Replacement of an essential element cation released from a soil particle by a proton.
Cavitation: The rupture of the water column in the xylem, when tension surmounts the cohesive nature of water.
Cell: Microscopic structure forming the basic structural and functional unit of living organisms. It encompasses nuclear and cytoplasmic material enclosed by a cell membrane.
Cell Biology: Branch of biology involving the study of cells, their structure, formation, components and functions.
Cell Cycle: Sequence of events occurring during cell division.
Cell Division: Process of division of cell with the purpose of growth or reproduction.
Cell Membrane: The semipermeable membrane sheathing cytoplasmic material of the cell.
Cell Plate: During cell division, the plate formed at the midpoint between two sets of chromosomes, which is involved in the wall formation between two daughter cells.
Cell Sap: Fluid present in the central vacuole of plant cells.
Cell Wall: The rigid boundary forming the outer structure of plant cells.
Cellulose: A complex carbohydrate composed of glucose units, which forms the major constituent of cell wall in plant cells.
Central Cell Nuclei: Mostly two in number nuclei uniting with sperm to form primary endosperm nucleus in embryo sac. It is a membrane enclosed organelle of eukaryotic cells that contains its genetic material in the form of chromosomes.
Centrioles: Small, cylindrical cell organelles found in animals and some algae and fungi. Located near the nucleus in the cytoplasm of most eukaryotic cells each centriole is usually composed of nine triplets of microtubules.
Centromere: Portion of the chromosome holding the two chromatids together before anaphase stage of mitosis or anaphase II stage of meiosis. The spindle fibers are attached to this region and move the chromosomes during cell division.
Chemiosmotic Phosphorylation: Occurring in mitochondria and chloroplasts, this prcoess involves the synthesis of ATP from ADP and phosphate unit.
Chemosynthetic Origin of Life: Theory according to which life began via a series of chemical reactions on primitive Earth.
Chiasma: X-shaped structure formed by the attachment of two chromatids of homologous chromosomes to each other during meiosis.
Chitin: Polymer composed of partly amino sugars, it is a semitransparent hard substance forming the outer covering or exoskeleton of crustaceans, arachnids and insects.
Chlorenchyma: Parenchyma tissues with chlorophyll content.
Chlorophyll: Green pigment found in plants, cyanobacteria and algae, which is involved in capturing light energy required for photosynthesis.
Chloroplast: Plastids opulent in chlorophyll content that carry out photosynthesis.
Chlorosis: Process of yellowing of leaves, occurring due to lack of chlorophyll.
Chromatid: One of the two identical chromosome strands united by a centromere into which the chromosome longitudinally splits while preparing for cell division.
Chromatin: Found in chromosomes, chromatin is a readily staining substance of a cell nucleus containing DNA, RNA and other proteins that form chromosomes during cell division.
Chromoplast: Plastids containing pigments other than chlorophyll, usually imparting red or yellow color.
Chromosome: Threadlike bodies made up of DNA coiled tightly several times around proteins called histones. Its structure consists of chromatids joined together at the centromere.
Chromosome Condensation: Also called pachytene, this process is a part of prophase I, wherein the chromosomes become shorter and thicker.
Cilium: Precisely arranged, short microtubules found mostly in bunches, similar to a flagellum. These may either be sensory or locomotory organelles.
Circadian Rhythm: A rhythmic daily activity cycle exhibited by many organisms in an intervals of 24 hours.
Citric Acid Cycle: In aerobic respiration, the complex series of reactions following glycolysis, which involve mitochondria, ATP and enzymes.
Cladophyll: Also called phylloclade, this is a flattened stem that looks like a leaf.
Class: In classification, the category coming between a division and order.
Cloning Vector: Molecule of DNA that replicates and transfers DNA from one cell to another.
Closed Carpel: Is another phrase used for Angiosperms that are plants with seeds inside the ovary.
Coccus: Sphere shaped bacteria.
Codon: Triplet of adjacent nucleotides in messenger RNA, which specify the amino acid to be incorporated into a protein.
Coenocytic: Large cells containing myriad nuclei. It is formed when the cell nucleus divides multiple times without the actual division of the cell.
Coenzymes: Molecules providing transfer site for biochemical reactions catalyzed by enzymes.
Cohesion-Tension Theory: This theory explains that the upward pull of water takes place by the combination of water molecules cohesion in the vessels and tracheids and tension on the water column caused by transpiration.
Coleoptile: The first leaf above ground level forming a sheath around the tip of the stem, so as to protect the emerging shoot (plumule) of monocotyledons like grasses and oats.
Coleorhiza: Sheath formed around the emerging radicle in plants of the monocotyledons like the grass family.
Collenchyma:Cells containing primary walls thickened at the cells corners, but thin elsewhere.
Companion Cells: Specialized parenchymal cells situated beside sieve tubes in the phloem of angiosperms that regulate flow of nutrients through the sieve tube.
Compost: Combination of several dead and decaying organic substances, such as manure, dead leaves, etc. used for soil fertilization.
Compound Leaf: Leaf blade divided into distinct leaflets attached via a common petiole.
Conidium: Fungal spore formed outside a sporangium and produced asexually.
Conifer: Woody trees or shrubs that are gymnosperms and bear cones.
Conjugation: Process of genetic exchange occurring in bacteria and some green algae, wherein the DNA is passed through a tube connecting adjacent cells.
Cork: Outer tissue layer of an old woody stem produced by cork cambium, whose cells are saturated with suberin at maturity.
Cork Cambium: Lateral meristematic tissue ring found in woody seed plants between the exterior of woody stems or roots and central vascular tissue. It produces cork to its exterior and phellogen to its interior.
Corm: A thick food storing, vertically oriented stem enveloped by some papery nonfunctional leaves.
Corolla: Collective phrase used for the petals of a flower.
Cortex: Generally parenchyma cells forming a tissue extending between the vascular tissue and epidermis.
Cotyledon: A seed leaf or embryo leaf that usually absorbs or stores food.
Crossing-over: The exchange during prophase I in meiosis, between corresponding segments of chromatids of the homologous chromosomes.
Crown Division: Asexual type of reproduction, involving the division of the base of the stem.
Cuticle: Thin hyaline film derived from the exterior surfaces of epidermal cells, covering the surface of plants.
Cutin: Fatty or waxy substance making up the cuticle.
Cutting: Vegetative plant parts used for asexual propagation.
Cyclosis: Flow of cytoplasm with the cell.
Cytochrome: Protein containing iron, acting as small electron carriers by transferring molecules in electron transport system.
Cytogenetics: Study of genetic effects of chromosome behavior and structure.
Cytokinesis: Cell division followed by mitosis.
Cytokinin: Growth hormone concerned with cell division and other metabolic activities of the cell.
Cytoskeleton: Network of microfilaments and microtubules that protects and maintains cell shape, enables cellular motion and plays important roles in both intracellular transport and cell division. It is present in both prokaryotes and eukaryotes.
Cytosol: Fluid part of the cell into which the organelles are scattered.
Dark Reactions: Stage of photosynthesis which is light independent wherein carbohydrates are synthesized from carbon dioxide.
Day-neutral Plant: Plants independent of specific day lengths for commencement of flowering.
Deciduous: The plants that shed their leaves before a dry season to minimize the transpirational loss of water.
Decomposer: Organism breaking down organic matter into forms suitable for recycling.
Dedifferentiate: Pertaining to cells, dedifferentiate means becoming less specialized.
Deoxyribonucleic acid (DNA): Nucleic acid containing genetic instructions used for the proper functioning and development of all living organisms.
Development: Changes pertaining to the growth and differentiation of plant cells into various tissues and organs.
Diatom: Unicellular, microscopic, freshwater or marine algae belonging to phylum Chrysophyta, which contain two silica shells fitting together like parts of a petri dish.
Dichotomous Branching: Fork resulting into two somewhat equal branches, as in the case of leaf veins or secretory ducts.
Dicotyledon: Angiosperm class whose seeds feature two cotyledons.
Dictyosome: Organelle comprising disc-shaped, mostly branching hollow tubes, which accumulate and pack substances required for the synthesis of various materials in the cell.
Differentially Permeable Membrane: Membrane permitting the diffusion of various substances at different rates.
Differentiation: Conversion of relatively unspecialized cell to a better specialized cell.
Diffusion: Haphazard movement of molecules from regions of high concentration to regions of lower concentration, leading to uniform distribution and leveling of the different concentration areas.
Digestion: Conversion of insoluble, complex substances into soluble, simpler substances under the control of enzymes.
Dihybrid Cross: Cross involving heterozygous parents with two different gene pairs.
Dikaryotic: Presence of two nuclei in a cell.
Dioecious: Plants featuring unisexual cones or flowers, with the male cones and flowers belonging to certain plants and the female cones and flowers confining to certain other plants of the same species.
Diploid: Cells comprising two sets of chromosomes in the nucleus. This is denoted by the term n’, and is a characteristic of the sporophyte generation.
Diuretic: Substances that increase the urine flow.
Divergent Speciation: Emergence of a new species from a part of existent species, with the remnant species continuing as the original species itself, or else transforming into a new species.
Dominance: Phenomenon in which one allele of a gene masks the phenotypic expression of another allele of a gene. The allele masking the other allele is called dominant allele.
Dormancy: The phase of temporary growth cessation in plants, under harsh environmental situations, wherein the regular conditions required for growth cannot be met.
Double Fusion: Phenomenon in which one sperm fertilizes an egg to form a zygote, while another sperm fertilizes the central cell nuclei (polar nuclei) forming a primary endosperm nucleus.
Drupe: Fleshy fruits with one or more seeds enclosed within a hard protective layer called endocarp.
Early Wood: Wood formed during the early part of the growing season, characterized by large, thin walled cells. It features large number of vessels in angiosperms and in gymnosperms, it features wide tracheids.
Ecology: Branch of biology involving study of interactions of organism with the environment and with each other.
Ecosystem: System involving the interactions of living organisms with each other as well as with the non-living environment.
Ectomycorrhiza: One type of mycorrhizal association, wherein the fungi do not invade the cell membrane, instead invade the root cortex cells.
Egg: Non motile female gamete.
Elater: Small, twisted, strap-like, elastic filament, usually occurring in pairs that push the spores out of the sporangium, thereby assisting in spore dispersal.
Embryo: The immature sporophyte formed after fertilization from the zygote in the archegonium or ovule.
Enation: Tiny green leaf like structures growing on the stems of whisk ferns and do not have vascular tissue.
Endocarp: The innermost layer of the fruit wall enclosing the seed in fleshy fruits.
Endocytosis: Absorption of solid or liquid material into a cell by means of invagination of the plasma membrane to surround the material and pinching shut to form a vacuole or vesicle around it.
Endodermis: Single layer of specialized parenchyma cells surrounding the vascular tissues in the roots and stems. It forms the inner boundary of the cortex.
Endoplasmic Reticulum: Complex system of narrow tubes and sheets forming a network in the cell’s cytoplasm. It divides the cytoplasm into various compartments. The endoplasmic reticulum may or may not have ribosomes attached to them.
Endosperm: Nutritive material derived from the embryo sac in seed plant ovules. It furnishes the developing embryo and seedling with nutrition.
Endosymbiont Hypothesis: According to this hypothesis, mitochondria and plastids were free-living bacteria, which got incorporated into the cells.
Enzyme: A type of complex protein that enhances the rate of a chemical reaction in living cells, without itself being used in the reaction.
Epicotyl: Portion of the seedling above the cotyledon’s attachment point.
Epidermis: Single layer of cells, forming the outer tissue of leaves, roots and young stems.
Epigynous: Term used to describe a condition in which the flower parts are attached above the ovary.
Epiphyte: Plants growing above the ground, that attach themselves to other plants without being a parasite. They derive their nutrients and water from air, dust, rain, etc.
Essential Element: Elements which are essential for normal development, growth and reproduction of plants. Nitrogen, calcium, magnesium, phosphorus, etc. are examples of some essential elements.
Etiolation: Term referring to a condition involving poor leaf development, long internodes, pale and weak appearance of the plant due to deprivation of sunlight.
Eukaryotic: Cells comprising nucleus, chromosomes and distinct membrane bound organelles.
Eutrophication: Process of nutrient accumulation in the water bodies resulting in its gradual nutrient enrichment. This entails to increase in the growth of algae and various other organisms.
Exine: Outer coat of a spore or pollen grain.
Exocarp: Outermost layer of the fruit wall.
Explant: Severed portions of the plant example: leaf or stem tissue that are utilized for tissue culture.
Extranuclear DNA: DNA located outside the nucleus, as seen in mitochondria and plastids.
Eyespot: Tiny reddish sensory organ, which is sensitive to light. It is found within motile unicellular organisms.
Facultative Aerobe (Facultative Anaerobe): Organisms that use oxygen when available, however, can even live without it.
Family: Category of classification above the genus category and below the order category.
Fermentation: Type of respiration involving the process of glycolysis, wherein lactic acid or ethyl alcohol are formed as an end product.
Fertilization: Fusion of two gametes to form a zygote.
Fiber: Cells which are long and thick walled, often containing protoplasm which is dead at maturity.
Fibrous Root System: Cluster of similarly sized roots. It is found in some dicots and most monocots.
Filamentous Body: Usually green algae cells exhibit this kind of body, wherein the cells are held firmly by a middle lamella when they divide transversely.
First Filial Generation: Progeny of an experimental cross between two parent species.
Fission: Cell division of bacterial and other related organisms that results into two new cells.
Flagellum: Multicellular organisms produce threadlike structures, which protrude from the motile cells and assist mainly in locomotion.
Floret: Tiny flowers belonging to the inflorescence of members of the grass family or sunflower family.
Fluid Mosaic Model: A plasma membrane model according to which, the proteins are embedded in the lipids throughout the membrane which gives a mosaic appearance to it. The proteins change their position, hence, it is called a ‘fluid’ membrane.
Follicle: It is a dry, monocarpellary, unilocular, multi-seeded fruit.
Food Chain: Natural chain of organisms, in which each organism of the chain feeds on members below it in the chain, and is consumed by organisms above it in the chain.
Foot: Attached to the gametophyte, the foot is the basal portion of the embryo of bryophytes and absorbs food from the gametophyte.
Founder: Individuals who are the first to establish a population in a new environment or habitat.
Freely Permeable Membrane: Membranes permitting all kinds of substances to pass through it.
Frond: Usually used for a fern leaf, however, occasionally it is also used to denote palm leaves.
Fruit: In angiosperms, the ripened ovary wall produced from the flower, usually containing seeds.
Gametangium: Cell in which gametes are produced.
Gamete: Haploid sex cells ovum and sperm which unite to form a zygote.
Gametophore: Leafy stalk on which the gametangium(sex organs) is borne.
Gametophyte: Haploid plant that produces gametes.
Gemma: Cluster of cells that get detached from parent body and possess the ability to develop into a completely new organism or plant. Seen in liverworts and mosses.
Gene: Basic unit of heredity, involving sequence of nucleotide containing necessary information for the structure and metabolism of an organism.
Gene Bank: It is a way of preserving plants and seeds for their germ plasm.
Gene Pool: Total number of all alleles in all the sex cells present in the individuals of a population.
Gene Synthesizer: Machine producing specific DNA sequences.
Genetic Drift: Alteration in the genetic makeup of a particular population, which mostly takes place by chance alone.
Genetic Engineering: Introduction of genes from one DNA form into another, by artificial means is called genetic engineering.
Genetics: Branch of biology involving the study of heredity, which deals with the differences and resemblances of organisms entailing from the interaction of their genes and the habitat.
Genus: Classification category located between a family and species.
Germ-line Mutation: Mutation occurring in the cells from which gametes are derived.
Germ Plasm: Aggregate of all genes of a species or organism groups.
Germination: Commencement or resumption of growth of a spore or seed.
Gibberellin: Group of plant hormones possessing different effects on growth, which are mostly related to enhancement of stem elongation.
Gills: Flattened plates of compact mycelium radiating to the outer region of the stalk on the bottom portion of the mushroom cap.
Girdling: Phenomenon involving the discarding of a band of tissues which extend to the inner side of the vascular cambium on the woody plant stem.
Glycocalyx: Mucilaginous secretion surrounding many prokaryotic cell walls.
Glycolysis: Cycle in which glucose is broken down to form pyruvic acid.
Glycoprotein: Proteins featuring attachment of sugars, which are less than ten sugars long.
Golgi Body: Organelle comprising layers of flattened sacs, which absorbs and processes synthetic and secretory products from the endoplasmic reticulum and then secretes them to the cell’s exterior or releases them into different parts of the cell.
Graft: Unification of the scion (shoot) of one plant and stock (root) of another plant.
Granum: The chloroplasts in vascular plants exhibit the presence of a series of stacked thylakoids, called granum.
Gravitational Water: After rain, the water draining into the pores of the soil is called gravitational water.
Ground Meristem: The mersitem producing all the primary tissues of the plant except the epidermis and the stele.
Guard Cell: Pair of specialized cells surrounding the stomata. These help in transpiration.
Guttation: Exudation of water from the leaves in the form of droplets due to root pressure.
Gymnosperm: Type of plants in which the seeds are not enclosed in the ovary during the development.
Habitat: The natural environment in which the plant completes its life cycle.
Haploid: Possessing one set of chromosomes in each cell. Denoted by ‘n’.
Hardwood: The wood of both dicot trees and shrubs are termed as hardwood. A dicot wood generally contains fibers.
Haustorium: Organ bearing semblance to a root, which is used by a parasite to penetrate into the host plant to absorb nutrients.
Heartwood: Darker colored non-living wood, whose cells have stopped conducting water.
Herbarium: Collection of plant specimens, which are pressed, dried, mounted on paper, identified and then labeled.
Heterocyst: Thick walled, transparent, slightly enlarged cell located in the filaments of certain cyanobacteria.
Heterokaryosis: Condition pertaining to certain cells in fungi, which feature two or more nuclei of different mating types.
Heterospory: Formation of both megaspores and microspores.
Heterotrophic: Organisms that depend on other organisms for nutrition, as they are incapable of synthesizing their own food.
Heterozygous: Possessing two different alleles of a trait on homologous chromosomes, which are situated at the same locus.
Histones: Basic nuclear proteins forming complexes with DNA to form nucleosomes and then complexing further to form chromosomes.
Hold Fast: Filament like organ of attachment present in algae that holds the algae to the substrate.
Homokaryosis: Condition in fungi, wherein all nuclei in the mycelium are genetically identical.
Homologous Chromosomes: Diploid nucleus comprising a pair of chromosomes, one inherited maternally and the other paternally.
Homozygous: Possessing two identical alleles on a homologous chromosome pair at the same locus.
Hormone: Organic substances produced mostly in small amounts in one part of the organism and then transported to different parts of the organism, where it controls the growth and development of the organism.
Hybrid: Heterozygous progeny of two parents differing in one or more inheritable attributes.
Hybrid Sterility: Post-zygotic isolation process, wherein a hybrid zygote develops into an adult, however, is incapable of forming fertile gametes.
Hydathode: Specialized leaf structure located at the leaf’s tip, from which the water is forced out when root pressure increases.
Hygroscopic Water: Water chemically adhering to soil particles due to which they are unavailable to plants.
Hymenium: Layer of fertile cells producing spores in a fungus fruiting body.
Hypha: Threadlike like tubular filaments found in fungi.
Hypocotyl: Portion between the cotyledon and the radicle in a seedling or embryo.
Hypodermis: Cell layer following the epidermal layer and distinct from the cortical parenchyma cells in some plants.
Hypogynous: Condition featuring attachment of flower parts below the ovary.
Immobile Essential Element: Element that cannot be removed from mature tissues. This means if young tissues become deficient in these elements they develop a deficiency, even though this element is present in the older tissues.
Imperfect Flower: Flowers lacking either carpels or stamens or both.
Imperfect Fungi: Those fungi that do not sexually reproduce or their sexual reproduction behavior has never been monitored.
Impermeable Membrane: Membranes that do not permit the passage of any substances across them.
In vitro: Carrying out growth of cells in artificially maintained media, such as test tubes, flasks, etc. instead of inside a living organism.
Inbreeding: Process of individuals with common ancestry mating together.
Inbreeding Depression: Condition in which individuals with common ancestry exhibit low fertility and poor performance.
Incipient Plasmolysis: The point at which the protoplasm just begins to stop exerting pressure on the cell wall, when the plant cell membrane shrinks after losing water.
Indusium: Umbrella shaped membranous tissue covering, located on the fern sorus.
Inferior Ovary: Ovary appearing to have its floral parts like calyx, corolla and stamens attached to the top of it. The appearance is due to the unison of the floral parts.
Inflorescence: Discrete group of flowers attached to a common axis in a specific order.
Integument: Outermost wall of the ovule, which develops into the seed coat. In angiosperms, the ovule has two integuments, while in gymnosperms, a single integument is seen.
Intercellular Space: Space present between two adjacent cells.
Intermediate-day Plant: Plants characterized by two critical photo periods. This means the plant will not flower during too short or too long days.
Internode: Region between two nodes.
Interphase: Phase of cell cycle which is not cell division but encompasses phases such as G1, S, G2. Here, the cell prepares for cell division.
Intrinsic Protein: Protein deeply integrated into the membrane, which cannot be discarded from the membrane easily.
Isogamy: Sexual reproduction taking place between gametes that are similar in size. Seen in certain fungi and algae.
Jungle: A dense growth of various plants where many organism can thrive. Forest is another term used for a jungle.
Junipers: This term refers to members of the Family Cupressaceae, and are characterized needle-like leaves in juviniles and scale-like leaves and cones in the adults.
Jointed Stems: Stems made up of one jointed, three dimensional and ribbed parts, more like a clump from where branches shoot.
Kinetochore: During late prophase, some specialized protein complexes are developed on the vertical faces of a centromere, and are called kinetochore.
Kingdom: Highest level of classification category.
Knot: Projection of plant tissue in the stem, root, etc. especially when swollen.
Karyogamy: Fusion of two gametes of the nuclei after plasmogamy (protoplasmic fusion).
Karyokinesis: Process of division involving series of active changes in the nucleus of a cell.
Key: Tools used to identify unfamiliar plants. Comprise mainly of pairs of choices.
Lamina: Expanded, flat, broadened portion of the leaf. Lamina is also referred to as leaf blade and does not include the petiole.
Late Wood: Also referred to as summer wood, this is the wood formed late in season, in the secondary xylem. It usually comprises narrow tracheids in gymnosperms and few or no vessels in angiosperms.
Lateral Roots: The scores of tiny roots stemming from the tap root.
Laticifer: Specialized ducts or cells that bear resemblance to vessels. These form a network of cells in the phloem and other plant parts that secrete latex.
Leaf: Expanded, flattened and usually green structures of the plant, arranged in various ways on the stem. If green, they act as sites for photosynthesis.
Leaf Gap: Area above leaf trace, wherein conducting tissues are absent as seen in fern vascular tissue.
Leaf Scar: Portion of the stem, wherein the leaf was attached, before its abscission.
Leaf Trace: Vascular bundles extending from the stem into the cortex and then protruding their way into the leaf.
Leaflet: Subdivisions of the leaf lamina as seen in compound leaves.
Legume: Dried fruits comprising seeds adhering to their edges which split along two seams.
Lenticel: Spongy cluster of cells located in the bark of woody plants, which allow gas exchange between the external atmosphere and interior of a plant.
Leucoplast: Colorless plastids that store starch.
Lichen: Fungi living in symbiotic union with algae. They appear either leaf-like, crust-like or in the form of branching trees, rocks, etc.
Light-dependent Reactions: Chain of chemical reactions involving the conversion of light energy into chemical energy with the assistance of chlorophyll pigment.
Light-independent Reactions: Cyclic sequence of chemical reactions utilizing carbon dioxide and energy released during the light-dependent reactions. These reactions are independent of light, and take place in the stroma of chloroplasts.
Lignin: Type of polymer impregnating some cell walls, like those of wood.
Ligule: Small tongue like structures located at the base of the spike moss.
Linked Genes: Genes situated close together on the same chromosome that crosses over only rarely.
Lipid: Hydrophobic and water insoluble compounds, such as waxes, fats, oils, etc.
Locule: Hollow situated within a sporangium or ovary.
Locus: Position of gene on a chromosome, which is determined by the linear order relative to the various other genes situated on the same chromosome.
Long-distance Transport: Transportation of substances from one cell to another cell, which is situated at a far away location.
Long Shoot: These shoots feature tiny papery leaves as observed in conifers.
Lumen: Inner portion of cell structures such as vacuole, vesicle, resin duct or oil chamber.
Mass Selection: Plant breeding procedure involving formation of an amalgamated population via selective harvesting of individuals from a population which is heterozygous.
Maternal Inheritance: Condition in which offspring receives extranuclear material from the female gamete.
Mating Types: Biochemical attributes that differentiate one mating type from the other. Gametes associated with the same mating type cannot fuse, and require compatible mating types for syngamy.
Megagametophyte: Female gametophyte produced by the megaspores of heterozygous plants.
Megaphyll: Present in all seed plants and ferns. It is a leaf that has evolved from a branch system and is characterized by branching veins.
Megasporangium: Sporangium in which only megaspores are produced.
Megaspore: Spore that advance into female gametophyte.
Megasporocyte: Diploid cells undergoing meiosis to form megaspores.
Meiosis: Process of cell division, wherein chromosomes replication is followed by two successive nuclear divisions. The resulting spores inherit a haploid set of chromosomes.
Meristem: Region of undifferentiated, actively dividing, growing cells from which new cells emerge.
Mesocarp: Central portion of the fruit wall, which is sandwiched between the outer exocarp and inner endocarp.
Mesophyll: Tissues (parenchyma or chlorenchyma) situated between the epidermal layers of the leaf.
Messenger RNA: Single stranded RNA molecule carrying genetic information from the DNA template to the site of protein synthesis.
Metaphase: Phase two of mitosis, wherein the chromosomes drift towards the center of the spindle.
Microphyll: Type of leaf characterized by single unbranched vein, and present in lycophytas.
Micropropagation: Plant propagation from single cells under artificial conditions as created in the laboratory.
Micropyle: Opening located in the ovule’s integuments, through which the pollen tube gains access to embryo sac or archegonium.
Microsporangium: Sporangium in which only microspores are formed.
Microspore: Spore developing into male gametophyte.
Microsporocyte: Diploid cells which on completion of meiosis produce microspores.
Microsporophyll: Small leaf like structure producing microspores.
Microtubule: Single proteinaceous tube like structure situated mostly in the plasma membrane. It regulates cellulose addition to the wall of the plant cells.
Middle Lamella: Layer of adhesive substance rich in pectin, which cements the cell walls of adjacent cells of multicellular plants together.
Midrib: Main middle vein of a leaf (pinnately veined) or leaflet.
Minor Veins: Small veins present on the leaf that branch off the lateral veins.
Mitochondrial DNA: Double stranded genetic material found in the mitochondria of cells.
Mitochondrion: Rod shaped organelles present in several eukaryotic cells, that work as powerhouse of the cell, by breaking down oxygen and nutrients and releasing energy in the form of ATP.
Mitosis: Nuclear division in which nuclear chromosomal material is initially duplicated and then split into two equal portions. Each daughter nuclei receives one portion of the nuclear chromosomes, thereby producing two genetically identical daughter nuclei.
Molecular Pump: Protein embedded in the membrane that forces molecules to pass from one side to another with the help of energy.
Monocotyledon: Angiospermic plants whose seeds possess one cotyledon.
Monoecious: Plants which possess both unisexual male and female flowers or cones on the same plant.
Naked DNA: Gene transfer processes such as transformation and transfection involves the passage of nucleosome and histone free DNA. This histone and nucleosome free DNA is called naked DNA.
Nastic Movement: Non-directional movement of flat plant organs such as leaf, petal, etc. irrespective of the stimulus position.
Natural Selection: The process of evolution involving the population rise of organisms which have inherited the traits that enable them to successfully survive in natural conditions and reproduce successfully in comparison to others.
Necrosis: Death of plant cells or tissues, leading to discoloration of leaves and stems. It can even conduce death of the plant.
Necrotroph: Fungus which attacks the host in a virulent manner, and then kills it. They then absorb all the nutrients from the dead organism.
Nitrogen Assimilation: Process of ammonium incorporation into organic compounds present within an organism.
Nitrogen Fixation: Process by which plants convert atmospheric nitrogen into compounds such as nitrate or ammonium, which they can readily use.
Node: Point of attachment of the leaves.
Nucellus: Central region of an ovule, wherein embryo sac development takes place.
Nuclear Envelope: The porous double lipid bilayer sheathing the nucleus.
Nucleic Acid: Macromolecule composed of chains of nucleotides, carrying genetic information.
Nucleolus: Spherical structure which is non-membranous and comprises proteins and nucleic acids. It is present within the nucleus, and each nucleus may contain more than one nucleolus.
Nucleotide: Chain of molecules which make up the structural units of DNA and RNA. Nucleotides comprise a sugar, nitrogenous base and phosphate group.
Nucleus: Largest cell organelle found in most eukaryotic cells. It contains most of the cell’s genetic material, thus is involved with inheritance, ribosome synthesis and metabolism control.
Nut: A dry fruit consisting of only one seed and a thick pericarp. Nuts feature a cluster of bracts at their base.
Obligate Aerobe: An organism that requires air for aerobic cellular respiration. They use oxygen in order to oxidize substrates and obtain energy.
Oogamy: It is a kind of sexual reproduction where the female gamete is non motile and larger than the motile male gamete.
Oogonium: It is the term given to the female sex organ of various algae and certain fungi.
Operculum: The covering that protects the peristome of the moss sporangium.
Organelle: The membrane bound cell bodies found in the cytoplasm. E.g. mitochondria.
Osmosis: The differential behavior of membrane for the purpose of diffusion of water and other solvents. Osmosis always takes place from the region of higher concentration to lower concentration.
Osmotic Potential: This is the minimum pressure required to prevent osmosis from taking place. It is the pressure developed by a solution that is separated from water by a selectively permeable membrane.
Outcrossing: The pollination which takes place between two different flowers which may or may not belong to the same genetic line.
Ovary: That part of the flower which is situated at the base of the pistil and contains an ovule (or ovules) and eventually develops into a fruit.
Overtopping: The ability of a shoot to grow for longer period of time than the other shoot in the same plant, which was a result of branching.
Oxidation Phosphorylation: The energy released during metabolic pathways, which is responsible for the formation of ATP and ADP.
P-protein: This is a fibril protein which is responsible for plugging sieve pores and precludes outflow if sieve elements are damaged.
P-protein Plug: It relates to the obstruction of a sieve region or sieve plate by bast protein.
Palindrome: This term refers to a DNA sequence which can be read forward or backward.
Palisade Mesophyll: It is also known as palisade or palisade parenchyma, and is the upper layer of ground tissue in a plant leaf. It comprises prolonged cells underneath and vertical to the upper cuticle, and constituting the principal area of the photosynthesis process.
Parenchyma: These are cells comprising only thin primary walls. All other features and functions vary from one kind to another.
Parthenocarpy: It is the activity wherein a fruit is produced without egg fertilization in the ovary.
Pedicel: A pedicel is one of the subordinate stems in a ramous inflorescence, bearing a single flower.
Peduncle: It is the stem which holds either a bunch of flowers or a solitary flower.
Perennial: This term refers to the plants which have a life cycle that lasts for over two years.
Pericarp: It relates to the matured and diversely altered walls of a plant ovary.
Pericycle: It is the outermost cell layer of the stele in a plant, which often turns into a zone that is multi-layered.
Periderm: This term pertains to the bark, and comprises cork, cork cambium, and any enclosed tissues like secondary phloem.
Perigynous: This simply means located around the pistil on the edge of a concave receptacle, as stamens or flower petals.
Peristome: The circles of tiny, pointed, odontoid outgrowths around the opening of a capsule or urn of mosses which appear when the lid is removed.
Petals: The colored segments of the corolla of the flower, which most often are involved in drawing in pollinating agents.
Petiole: The lithesome stem which attaches a leaf to the stem.
Phloem: It is a portion of vascular tissues that comprises sieve tubes, companion cells, parenchyma, and fibers. It forms the food-conducting tissue of a plant.
Photosynthesis: Photosynthesis is a plant activity which includes the synthesis of complex organic substances, peculiarly saccharides, from carbon dioxide, water, and inorganic salts, utilizing sunlight as a source of energy and with the help of chlorophyll and associated pigments.
Photosystem I and II: Photosystem I absorbs light for the transfer of negatron from plastocyanin to ferridoxin. Its reaction center is P700. Photosystem II absorbs light for oxidation of water and reduction of plastoquinone. Its reaction center is P680.
Phytochrome: This term pertains to a plant pigment which is involved in the soaking up of light in the photoperiodic response which modulates various types of growth and development.
Pinna: It is one of the basic divisions of a pinnated leaf.
Pistil: The female organ of a flower which bears ovules or seeds, consisting of a complete ovary, style, and stigma.
Pit: It is concerned with the portion of a sclerenchyma cell, where there is no secondary wall over the primary one, and substances are able to pass into or out of the cell.
Pith: This is a soft and squishy central cylinder of parenchymatous tissues in the stalks of plants having two cotyledons in the seed.
Plant Anatomy: Study of the internal structure of the plant.
Plant Geography: It is also known as phytogeography, phytochorology, geobotany, geographical botany, or vegetation science and refers to spatial distribution of plants and vegetation in different environment and regions.
Plant Physiology: The study of plants, which involves processes such as nutrition, reproduction, and other functions.
Plant Taxonomy: The science that refers to the identifications, description, naming, and classification of plants according to their unique characteristics.
Plasmodesmata: It pertains to a narrow hole in the elementary wall, that comprises some cytol, cell membrane, and a desmotubule. It is a means of communication between cells.
Plasmodium: Body of slime mold, which is a large mass of living substance with hundreds or thousands of karyons. Plasmodium ingest fungal spores, bacteria and other tiny protozoans.
Plasmolysis: It is an activity which relates to the shrinking of the living substances when water is removed by exosmosis.
Plastid: These are major organelles found in plant cells, as well as algal cells. These organelles are sites of manufacture of various essential chemical compounds used by the cell. They often contain chlorophyll, which is used for photosynthesis.
Plumule: It is the bud of the plant axis which moves up while it is still in the embryo.
Pneumatophore: It refers to a differentiated structure that originates from the root in particular plants which spring up in swamplands and fenlands, and act as a respiratory organ. E.g. Mangroove.
Pollen Grains: They relate to microspores in seed plants, that comprise a male gametophyte.
Pollen Tube: The protoplasmic tube which is squeezed out from a spudding pollen grain and develops toward the ovule.
Pollination: This natural process includes the conveyance of pollen from the anther to the stigma.
Pollinium: A cohered mass or body of pollen grains, characteristic of plants which belong to the orchid and milkweed families.
Polymer: It is a big chemical compound that consist of several subunits called monomers.
Pome: It pertains to the characteristic fruit of the apple family such as apple, pear or quince, in which the edible flesh grows from the greatly tumefied receptacle and not from the carpels.
Prickles: These are sharp protuberances of the cortex and cuticle.
Primary Pit Field: It is the region of the primary cell wall which is particularly thin and consists of many plasmodesmata.
Primary Producer: Any green plant which has the ability to convert light energy or chemical energy into organic substance.
Primary Tissue: Any tissue which is directly derived from distinction of an apical meristem or leaf primordium.
Procambium: It is the meristem from which vascular tissues originate.
Prochlorophytes: A class of procaryotes that possess both chlorophyll A and B, and is considered to be nearly associated to the antecedents of plastids in algae and plants.
Producer: A photosynthetic green plant or chemosynthetic bacterium, that comprises the first trophic level in a food chain.
Proembryo: This term relates to the cells which are forced into the endosperm and afterwards become the embryo, in seed bearing plant’s embryos.
Prokaryotes: Organisms which do not possess true nucleus or membrane-bounded cell organelles such as eubacteria, cyanobacteria, and archaebacteria.
Promoter Region: The area of a cistron in which control molecules and RNA polymerases bind during the process of cistron activation and transcription.
Prop Root: An adventitious root which holds the plant, as the aerial roots of the Rhizophora mangle tree or of the maize plant.
Prophase: The initial phrase of mitosis or meiosis in eukaryotic cellular division, during which the nuclear envelope breaks down and filaments of chromatin form into chromosomes.
Proplastid: A cytoplasmic cell organelle from which a plastid originates and develops.
Protein: The plant tissue that is rich in organic molecules which are believed as a food source providing necessary amino acids.
Protein Sequencing: This is a process that includes determining the amino acid sequences of its constituent peptides and also finding out what compliance it follows and if it comprises any non-peptide molecules.
Prothallus: A tiny, flat, and gentle structure developed by a spudding spore, that has sex organs, and is the gametophyte of ferns and some other plants. Its structure resembles a leaf.
Protoderm: A thin outer layer of the meristem in embryos and growing points of roots and stems, which gives rise to the epidermis.
Protonema: A threadlike structure created by sprouting of the spores in small leafy-stemmed flowerless plants and other related plants, and from which the leafy plant, that has the sexual organs, develops as a sidelong or terminal branch.
Protoplast: The living substance of a plant, including the protoplasm and cytomembrane after the cell wall has been removed.
Protoplast Fusion: A method by which two energids are coalesced to create hybrid cells that can develop into mature hybrid organisms normally performed on plants.
Protostele: The firm stele of most roots, that possesses a central core of xylem enclosed by bast.
Pure-bred Line: The homozygous dominant and homozygous recessive genetic constitution of a line which are selfed and utilized in spawning experiments.
Pyrenoid: A proteinaceous structure that is found within the chloroplast of specific algae and nonvascular plants, which is believed to be related to starch deposition.
Quantitative Trait: These traits are controlled by various genes and environmental factors. They are measured on a continuous scale.
Quiescence: Every plant requires some specific environmental conditions for its proper functioning and rapid growth. The growth or germination of the seeds or plants are hampered if these environmental conditions are not satisfied. This is termed as ‘quiescence’.
Quiescent Center: Quiescent center is the portion of the root situated at the apex of the plant tissue i.e. meristem in which cell division does not occur.
Rachis: Rachis is the extension of the axis of petiole or leafstalk in the compound leaf. All leaflets are attached to the rachis.
Radicle: Extension of the axis of petiole or leafstalk in the compound leaf. All leaflets are attached to the rachis.
Ray: Series of parenchyma cells that are radially arranged along the vascular region of the xylem and the phloem. These parenchyma cells transport food, water and other materials laterally in the roots and stems of woody plants.
Reaction Wood: Is formed when a woody plant encounters mechanical stress, as caused by wind exposure, soil movement and excess snow fall.
Receptacle: Expanded portion of the peduncle, wherein various parts of the flower are attached.
Recessive Trait: It is the trait that reflects in the phenotype only when the dominant gene is absent. E.g. color blindness.
Recombinant DNA: DNA molecule created either by crossing over in meiosis or under laboratory environement (in vitro). It is formed when DNA from at least two organisms is taken.
Red Tide: Marine phenomenon in which a reddish tint is formed on the water due to the sudden growth of cells in certain protozoa or red algae.
Reduction Division: Same as meiosis.
Reproduction: It is the birth of a new organism born either by sexual or asexual means.
Resin Canal: Tubular duct present in coniferous trees and seeds, which is lined with resin secreting cells.
Respiration: Cellular breakdown of sugar and other food molecules, in which a part of energy is utilized. If oxygen is utilized during the breakdown, it is known as aerobic respiration or else it is termed as anaerobic respiration.
Restriction Enzyme: Also called restriction endonuclease, this enzyme is capable of recognizing specific sequences in DNA at a specific site (restriction site), and then severing it.
Reticulate Venation: Reticulate venation is a thin, flat, laminar like structure of a leaf, featuring a net-like pattern of the veins, structured for the purpose of photosynthesis.
Retrovirus: Common type of plant virus whose genetic material is single-stranded RNA.
Rhizoid: Delicate root like filament that functions as a root in mosses and ferns. It provides support or performs the absorption function in them.
Rhizome: Horizontally oriented, underground root-like stem that has nodes and internodes.
Ribonucleic Acid (RNA): Type of molecule containing large amount of nucleotide units, wherein each nucleotide contains three elements- nitrogenous base, a ribose sugar, and a phosphate. It is involved in protein synthesis.
Ribosome: Cell organelle composed of proteins and ribonucleic acid (RNA), which is responsible for protein synthesis.
Root: Organ of the plant situated below the ground and absorbs water and mineral salts. Buds, leaves or nodes are absent in root.
Root Cap: Thimble-shaped mass of cells that cover and protect the growing tip of the root.
Root Hair: Hairlike outgrowth arising through the epidermal cell of the root. Located just behind the tip of the root, this root hair helps absorb water and nutrients from the soil.
Root Nodule: Plants forming symbiotic associations with nitrogen-fixing bacteria, exhibit swelling in their roots, at the region where the bacteria comes in contact with the root.
Runner: Slender creeping stem that contains long internodes, growing horizontally along the surface of the ground. E.g. strawberry plant.
Saprobe: Saprobes are heterotrophs which contribute to the various nutrient cycles by feeding on decomposing organic matter.
Sapwood: Sapwood is the outer wood which carries water from roots to the leaves in order to facilitate water storage for future use.
Sclereid: Sclereid is a cell, characterized by the presence of a thick secondary wall and absence of a protoplast.
Sclerenchyma: Sclerenchyma is a supportive tissue, found in plants, which is typically composed of hard, thick and dry cells.
Secondary Phloem: Secondary phloem is the phloem which is derived from vascular cambium.
Secondary Tissues: Secondary tissues are the tissues of the secondary plant body which are produced by vascular cambium.
Secondary Xylem: Secondary xylem is the xylem that is derived from vascular cambium.
Seed Coat: Seed coat, also referred to as testa, is the protective outer covering of seeds of various flowering plants.
Selectively Impermeable Membrane: It is a barrier which regulates the movement of substances, allowing some substances to pass rapidly, and others to slow down.
Selectively Permeable Membrane: It is a membrane that facilitates the transmission of certain molecules through it by the process of diffusion.
Selfing: Selfing is a process wherein a plant’s stigma is pollinated with pollen either from the same plant, or from a plant of identical genetic constitution.
Sepal: The sepal is the outermost part of a flower, resembling a leaf, which forms the calyx of the flower and surrounds its reproductive organs.
Septum: In botany, septum is a partition wall between two tissues.
Sessile: The term sessile, meaning without a stalk, is most often used in context of plants whose flowers or leaves grow directly from the stem.
Seta: Seta is a botanical term used to refer to the stalk of the capsule, which is located in between the foot and the sporangium.
Sieve Cell: Sieve cells are conducting cells of the secondary phloem, which have a narrow diameter and are more elongated in shape as compared to the sieve tube members.
Sieve Plate: Sieve plates are the pores, in the cell walls of the plant, which facilitate the movement of liquid matter.
Sieve Tube: Sieve tube is a tube formed by cells joined end-to-end in order to facilitate the flow of nutrients in flowering plants.
Simple Cone: A simple cone is a cone featuring only one axis or bearing only sporophylls.
Simple Leaf: A simple leaf is a single leaf blade sporting a bud at the base of the leaf-stem.
Sink: Sink is a botanical term used to refer to any tissue which receives the material that is transported by the phloem.
Siphonostele: Siphonostele is a type of stele, usually characterized by the formation of cylinder surrounding the central pith and possessing leaf gaps.
Softwood: Softwood refers to any of the various varieties of trees, usually coniferous, sporting narrow, needle like leaves.
Species: The term species is used to refer to a taxonomic group of plants or animals whose members can interbreed.
Spermatophytes: Spermatophytes are the plants that reproduce by means of seeds, instead of spores.
Spindle: Spindle is the underlying structure of microtubules which pulls away the chromosomes from the center of the cell, towards the poles during the process of nuclear division.
Spirillum: The term spirillum is used to refer to the spirally twisted bacteria, resembling an elongated rod, which is usually found in stagnant water.
Spongy Mesophyll: Spongy mesophyll are irregularly shaped and distinctly spaced parenchyma cells present in plant leaves.
Sporangium: The term sporangium is used to refer to a plant structure which produces and contains spores.
Spore: A spore is a unicellular asexual reproductive body in several nonflowering plants that facilitates the development of a new individual without sexual fusion.
Sporophyll: A sporophyll is a modified leaf bearing sporangia.
Sporophyte: Sporophytes are those plants which produce spores by the process of meiosis in order to produce gametophytes.
Stamen: The male organ of the flower consisting of the anther and the slender filament meant to hold it in position is known as the stamen.
Start Codon: The term start condon is used to refer to a set of three nucleotides which indicate the initiation of information for the process of protein synthesis.
Stigma: The place at the apex end of the style, where the pollen that’s deposited enters the pistil is known as stigma.
Stipules: Stipules are small leafy outgrowths, usually occurring in pairs, observed at the base of a leaf or the stalk.
Stoma: Stoma is a minuscule epidermal pore in the leaf or stem of the plant which allows gases and water vapor to pass through.
Stop Codon: The term stop codon is used to refer to the set of three nucleotides which indicate the termination of information for the process of protein synthesis.
Stroma Reactions: These are the set of reactions which occur in the stroma during the process of photosynthesis, without being directly powered by light.
Stromatolite: The stromatolite is a biological fossil representing colonies of bacteria, usually cyanobacteria, alternating with sediment layers.
Structural Region: It is the part of the gene, comprising nucleotide triplets, that specifies which amino acids are to be incorporated into protein.
Style: In plants, style is a narrow elongated part of the pistil, located between the ovary and the stigma.
Substrate Level Phosphorylation: It is the formation of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) by transferring a phosphate group from a substrate molecule.
Substrate Specificity: In botany, the term substrate specificity is used to refer to the ability of a given enzyme to distinguish one substrate from other similar substrates.
Suspensor: The suspensor is the cell or filament supporting a gamete, most often observed in a zygospore.
Sympatric Speciation: The speciation, i.e. the evolution of a biological species, which occurs within a limited geographical area is known as sympatric speciation.
Symplast: The inner side of the plasma membrane, wherein water and low molecular solutes diffuse freely is known as the symplast of the plant.
Synapsis: The pairing of two homologous chromosomes which occurs during the process of meiosis is known as synapsis.
Syngamy: Syngamy is the process fusion of a sperm and an egg.
Taxis: The movement of a cell that is triggered by external stimulus, towards or away from the stimulus source, is known as taxis.
Tendril: Tendril is a narrow stem-like structure which helps the twining plants in attaching themselves to an object in order to gain support from it.
Test Cross: The test cross is a process wherein a suspected heterozygote is tested by crossing it with a known homozygous recessive.
Thallus: Thallus is a plant which doesn’t feature true stems, roots, leaves or vascular system.
Thorn: Thorns, also referred to as spines, are the leaves of plants which are modified into cylindrical, hard structures featuring sharp ends.
Thylakoid: The thylakoid is a membrane-bound compartment within the chloroplasts and cyanobacteria which is a site for the light-dependent reactions of photosynthesis.
Tinsel Flagellum: A flagellum which is covered with several minuscule hairlike projections is referred to as tinsel flagellum.
Tip Layering: Tip layering is a plant propagation method wherein only the stem tip is buried in order to facilitate the growth of a new plant.
Tissue: A tissue is an ensemble of cells featuring similar structure and performing a specific function.
Tissue Culture: Tissue culture is a process wherein various cells are separated from each other and grown outside the body, on a culture medium.
Tracheid: The elongated cells in the xylem which facilitate the transportation of water and mineral salts within the plants are known as tracheids.
Transcription: A process facilitated by the enzymes to transcribe the information of a DNA strand into a complementary RNA(tRNA) strand is known as transcription.
Transformation: The modification of a cell by the intake and incorporation of an exogenous DNA is known as transformation.
Transgenic Plant: A plant which contains DNA inserted by some form of genetic engineering is known as transgenic plant.
Translation: The term translation is used to refer to a process wherein the sequence of amino acids is facilitated during protein synthesis by the information in an mRNA strand.
Translocation: The process of transportation of dissolved material within a plant is referred to as translocation.
Transpiration: In botanical studies, the process of emission of water vapor from the plant leaves is known as transpiration.
Transposons: The sequences of DNA which can move to different positions within the genome of a single cell through the process of transposition.
Transposition: A form of chromosomal mutation wherein a chromosomal segment is transferred to a new position on the same or some other chromosome.
Trichome: Trichomes are the various extensions developing from the epidermis of the plant which are meant to provide protection to the plant.
Tropism: A biological process, which indicates the growth of a plant, in response to the environmental stimulus is known as tropism.
Tuber: The various types of modified plant structures which are enlarged to store nutrients are known as tubers.
Tubulin: Tubulin is a protein which leads to formation of microtubules on polymerization.
Turgid: In botany, the word turgid is used to refer to a plant with swollen tissues which are filled with moisture.
Turgor Pressure: The outward pressure exerted by the water in the plant cells, which adds to the rigidity of these cells, is known as the turgor pressure.
Tylosis: The tylosis is the process wherein an outgrowth from a parenchyma cell, through the pit cavity into a vessel, leads to the blockage of the vessel.
Unisexual: Flowers that have either the pistil or the stamen are referred to as unisexual flowers.
Uniparental Inheritance: Genetic inheritance obtained from just one parent, and is generally the case for mitochondrial and plastid genes.
Vacuolar Membrane: The membrane sheathing the cell vacuole.
Vacuole: Fluid pocket separated from the cell cytoplasm by a membrane, which mostly occupies about 99% of the cell’s volume, and stores dissolved matter.
Vascular Bundle: Column of tissue comprising mostly phloem and xylem, which are usually enveloped by a bundle sheath.
Vascular Cambium: Meristem present in the form of narrow cylindrical sheath, that produces secondary xylem and phloem in the roots and stems.
Vascular Plant: Plants possessing the vascular tissues i.e. xylem and phloem are termed as vascular plants.
Vein: Branching network formed within the leaves by any of the vascular bundles is termed as vein.
Velamen Root: Aerial root capable of preventing water loss due to its multilayered epidermis.
Venter: Egg’s site in the large basal region of the archegonium.
Vernalization: Cold treatment required to initiate flowering in biennials.
Vessel: Occur in xylem of some vascular plants and most of the angiosperms. They appear as cylindrical tubes, whose cell cytoplasm has been lost. Vessels consist of vessel members that are laid from one end to another.
Vessel Element: Single conducting cells of the xylem featuring a few perforations, which permit flow of water from one vessel to another.
Viability: Seed’s or spore’s ability to germinate.
Water Potential: Amount of water that can be absorbed or released by a substance with respective to another substance is termed as water potential.
Water-splitting (Photolysis): Phenomenon occurring in photosystem II of the process of photosynthesis, wherein water molecules split to release oxygen.
Webbing: According to telome theory of megaphyll origin, the lamina originated from parenchymatic cell production between the telomes.
Whiplash Flagellum: Flagella featuring smooth surfaces are termed as whiplash flagellum.
Whorled: Arrangement of three or more leaves, flowers or other plant structures positioned at a node.
Wood: Secondary xylem produced in the stems of trees and other woody plants is called wood. Wood present in living trees perform the function of transferring water and nutrients to growing tissues.
Xylem: The portion of conducting vascular tissue that conducts water and dissolved minerals. It contains several types of cells such as tracheids, vessel elements, parenchyma, sclereids, fibers, etc.
Yeasts: Unicellular ascomycetes which lack mycelium. In yeasts individual cells itself perform the functions of a large mycelium.
Zone of Elongation: Root tip region which lies toward the root apical mersitem, where pronounced elongation of cells takes place.
Zoospore: Motile spore capable of swimming. Occurs in fungi and algae.
Zosterophyllophytes: Bunch of early vascular plants possessing xylem and exarch prostele. They also feature lateral sporangia which open transversely on the top edge.
Zygosporangium: Large multinucleate sporangium produced by the fusion of two compatible hyphae in Zygomycete fungi.
Zygote: Diploid cell conduced by the fusion of two gametes.
We know plants from time immemorial and they are a part of our day-to-day life, either directly or indirectly, but do we actually know what does a plant cell structure&hellip
The controversy over stem cell research is mainly centered in the creation and/or destruction of human embryos. Read on to know more.
Where is the research in stem cells heading? How much have we achieved and what is yet to be accomplished? Get to know some interesting stem cell research facts and&hellip
The discipline of terminology consists primarily of the following aspects:
- analyzing the concepts and concept structures used in a field or domain of activity
- identifying the terms assigned to the concepts
- in the case of bilingual or multilingual terminology, establishing correspondences between terms in the various languages
- compiling the terminology on paper or in databases
- managing terminology databases
- creating new terms, as required.
A distinction is made between two types of terminology work:
- Ad hoc work on terminology, which deals with a single term or a limited number of terms
- Systematic collection of terminology, which deals with all the terms in a specific subject field or domain of activity, often by creating a structured ontology of the terms within that domain and their interrelationships.
Ad hoc terminology is prevalent in the translation profession, where a translation for a specific term (or group of terms) is required quickly to solve a particular translation problem.
A terminologist intends to hone categorical organization by improving the accuracy and content of its terminology. Technical industries and standardization institutes compile their own glossaries. This provides the consistency needed in the various areas—fields and branches, movements and specialties—to work with core terminology to then offer material for the discipline's traditional and doctrinal literature.
Terminology is also then key in boundary-crossing problems, such as in language translation and social epistemology. Terminology helps to build bridges and to extend one area into another. Translators research the terminology of the languages they translate. Terminology is taught alongside translation in universities and translation schools. Large translation departments and translation bureaus have a Terminology section.
Terminology science is a branch of linguistics studying special vocabulary.
The main objects of terminological studies are special lexical units (or special lexemes), first of all terms. They are analysed from the point of view of their origin, formal structure, their meanings and also functional features. Terms are used to denote concepts, therefore terminology science also concerns itself with the formation and development of concepts, as well as with the principles of exposing the existing relations between concepts and classifying concepts also, with the principles of defining concepts and appraising the existing definitions. Considering the fact that characteristics and functioning of term depend heavily on its lexical surrounding nowadays it is common to view as the main object of terminology science not separate terms, but rather the whole terminology used in some particular field of knowledge (also called subject field).
Terminological research started seventy years ago and was especially fruitful at the last forty years. At that time the main types of special lexical units, such as terms proper, nomens, terminoids, prototerms, preterms and quasiterms were singled out and studied. [ further explanation needed ]
A nomen, or a nomenclature unit, is a name of a single notion or a certain unit of mass production,  e.g. prefix dis- Canon 550D UA-24 etc.
Terminoids, or jargon terms, are special lexical units which are used to name the phenomena that are absolutely new and whose concepts are not interpreted in a monosemantic way. E.g., Salmon Day, mouse potato, etc. 
Prototerms are special lexemes that appeared and were used in prescientific times. 
Preterms are a special group of lexemes which is represented by special lexical units used as terms to name new scientific notions. They are represented by a vast descriptive pattern, e.g. business process reengineering, management by walking about, etc. 
The main principles of terminological work were elaborated, terminologies of the leading European languages belonging to many subject fields were described and analysed. It should be mentioned that at the former USSR terminological studies were conducted on an especially large scale: while in the 1940s only four terminological dissertations were successfully defended, in the 1950s there were 50 such dissertations, in the 1960s their number reached 231, in the 1970s – 463 and in the 1980s – 1110.
As the result of development and specialising of terminological studies, some of the branches of terminology science – such as typological terminology science, semasiological terminology science, terminological derivatology, comparative terminology science, terminography, functional terminology science, cognitive terminology science, historical terminology science and some branch terminology sciences – have gained the status of independent scientific disciplines.
Terminological theories include general theory of terminology,  socioterminology,  communicative theory of terminology,  sociocognitive terminology,  and frame-based terminology. 
Improve your vocabulary by learning the exact meaning of words and how to use them correctly. These lessons are either words lists or lessons which focus on how to use a particular word correctly. For students aiming to reduce the number of errors in their writing and speaking, these lessons are essential.
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Wavelength is the distance between two identical adjacent points in a wave. It is typically measured between two easily identifiable points, such as two adjacent crests or troughs in a waveform. While wavelengths can be calculated for many types of waves, they are most accurately measured in sinusoidal waves, which have a smooth and repetitive oscillation.
Wavelength is inversely proportional to frequency. That means if two waves are traveling at the same speed, the wave with a higher frequency will have a shorter wavelength. Likewise, if one wave has a longer wavelength than another wave, it will also have a lower frequency if both waves are traveling at the same speed. The following formula can be used to determine wavelength:
Λ = v / ƒ
The lowercase version of the Greek letter "lambda" (λ) is the standard symbol used to represent wavelength in physics and mathematics. The letter "v" represents velocity and "ƒ" represents frequency. Since the speed of sound is roughly 343 meters per second at 68° F (20° C), 343 m/s can be substituted for "v" when measuring the wavelength of sound waves. Therefore, only the frequency is needed to determine the wavelength of a sound wave at 68° F. The note A4 (the A key above middle C) has a frequency of 440 hertz. Therefore, the wavelength of an A4 sound wave at 68° F is 343 m/s / 440 hz, which equals 0.7795 meters, or 77.95 cm.
Waves in the electromagnetic spectrum, such as radio waves and light waves, have much shorter wavelengths than sound waves. Therefore, these wavelengths are typically measured in millimeters or nanometers, rather than centimeters or meters.
Cultural definitions for jargon
A special language belonging exclusively to a group, often a profession. Engineers, lawyers, doctors, tax analysts, and the like all use jargon to exchange complex information efficiently. Jargon is often unintelligible to those outside the group that uses it. For example, here is a passage from a computer manual with the jargon italicized: “The RZ887-x current loop interface allows the computer to use a centronics blocked duplex protocol .” ( See slang.)
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