Clone - The entire vegetatively produced descendants from a single original seedling.

Closed (Vascular) Bunddle - A Vascular bundle lacking cambium, and cannot increase in diameter by normal secondary thickening.

Closed Community - A plant community completely covering the ground it occupies, and consequently not allowing the introduction of new species.

Club Fungi - Used for a group of fungi based on the structure of basidiocarp in order Aphylloporales of Hymenomecete fungi in which fruiting body has. a number of fingers or club-like projections e.g., clavulinopsis helvoa.

Club Mosses - Used for pteridophyte Lycopodium of the order Lycopodiales of Lycopsida having about 200 species, cosmopolitan in distribution, herbaceous having dichotomously branched stems bearing numerous small leaves arranged spirally on it and having no ligule.

Club Root (Finger-and-toe disease). Used for the disease of crucifers which is caused by fungus Plasmodiophra brassicae in which roots get swollen and malformed.

Coacervate (Protobiont) - An aggregation of large complex organic molecules bounded by an organic membrane.

Coccus - Any bacterium whose cell is having spherical or elliptical shape.

Cocolith - Used for small intricate plate of calcium carbonate, many of which form complete covering over the cell of certain algae belonging to division Haptophyta.

Cocolithophorids - Used for algal members of division Haptophyta which possess cocoliths over their cells. Such algae are marine and Cretaceous chalks have remains of numerous such algae.

Codominance - Used for describing the phenomenon of expression of both alleles of heterozygote in its phenotype.

Codon - Used for a sequence of 3 nucleotides (triplet) which can code for one specific amino acid in a polypeptide chain. Sequence of cordons will thus determine the sequence of amino acids in a polypeptide.

Coenobium - A group of algal cells which has a definite number and organisation. It behaves as an individual, often shows polarity, and produces identical daughter coenobia.

Coenocentrum. Used for describing a small deeply staining body at the centre of the multinucleate ecosphere of the Peronosporales, to which the egg-nucleus goes.

Coenocytic - Used for a thalloid plant body which is asceptate and multinucleate, structure is often thread-like e.g., hyphae of phycomycete fungi and algae of Xanthophyta.

Coenososros - Used for the condition where sporangia are in a continuous line as in fern pteridium where discrete sore are not formed.

Co-Enzyme - An organic substance which is essential for the activity of a particular enzyme. The co-enzyme can sometimes be separated from the active group of the enzyme.

Coenzyme I (diphosphopyridine nucleotide) Coenzyme II (triphosphopuyridine nucleotide). These are dinuc1eotides having adenine and nicotamide, acting as hydrogen carriers when substances get oxidized by dehydrogenases (See NAD and NADP).

Coenzyme A - A coenzyme which is necessary for the oxidative decarboxylation of pyruvates.
CH3COCOO- + CoA + 2H2O + 2H+ --CH3COO-CoA + HCO3 +H2
acetyl CoA
pyruvate
also:
Acetyl phosphate + CoA -- acetyl CoA + inorganic phosphate then: Acetyl CoA.+ oxaloacetate -- citrate + CoA
Coenzyme Q (Ubiquinone). Used for a lipid soluble electron carrying coenzyme which takes part in transport of electron from NAD to oxygen in the respiratory chain. Molecule is a reversibly reducible quinine.


Cofactor - Used for a non-protein component which is essential for the catalytic activity of some enzyme. It may be a metal ion e.g., zinc ion for alcohol dehydrogenase or a coenzyme.

Cohesion Theory - According to this theory, the reduction in water potential in the leaf due to an increase in the rate of evaporation makes the water to flow through the plant to replace the lost water. This theory explains the ascent of sap in the xylem.

Colchicine - C22H250 6N. An alkaloid drug which is extracted. from the corm of the autumn crocus Colchicum autumnale. It causes abnormal division of nuclei, resulting in an increase of the chromosome number forming a. polyploid.

Coleloptile - The first leaf of a grass seedling which appears above the ground first as a sheath around the plumule, and has little chlorophyll.

Coleorhiza, Coleorhiza - A protective layer of cells which is present around the radical of grass seedlings.

Coliphage - Any DNA bacteriophage which infects any strain of bacterium Escherich coli.

Collateral Bud - An accessory bud which is lying beside the maxillary bud.

Collateral Bundle - A vascular bundle with a strand of xylem, with a strand of phloem external to it on the same radius.

Collecting Cell - A thin-walled cell present in the mesophyll of a leaf below the palisade layer, and in contact with it. The collecting cell transports elaborated food-material from the palisade.

Collective Fruit - A single fruit which is formed from several flowers.

Collenchyma - A mechanical tissue of long cells having cellulose cell-walls thickened at the corners with cellulose. The cells are living and can elongate.

Colonial - Used for a structure made up of numerous cells which are similar in structure and function and more or less loosely aggregated together into the structure of some definite shape. For example, plant body of many algae like Volvox.

Colpus - An oblong to elliptical germinal aperture in a pollen grain atleast twice as long as broad. Pollens having such apertures are known as eolpate.

Columella - 1. Used for the central portion of the root cap of certain roots in which the cells are arranged in longitudinal lines.
2. A rod-like radial element which is. present in a pollen or spore wall.

Commensalisms - Used for any interaction which is taking place between two different living organisms in which one interacting partner is benefited while other is neither benefited nor harmed e.g., relationship of epiphyte with their host.

Community - A group of plants and animals that live together and inter act with one another in the same environmental conditions.

Companion Cell - A nucleated cell having dense cytoplasm, associated with a sieve-tube, with which it is devised from a common parent cell. It apparently plays some role in the functioning of the sieve-tube. Companion cells occur only in Angiosperms.

Comparatives Biochemistry - Used for the identification of discontinuities in biochemical variation and their subsequent use in construction of classification or correlation with existing classiffications.

Compensation Period - 'The time required by a green plant to be in light to make-up the carbohydrate which is lost during respiration in the dark.