Glossary  (Page 5/18)

Condensation The joining of two molecules by taking a water molecule from them (see Hydrolysis)

Cone A photoreceptor cell which is sensitive to bright light and colour

Conjunctiva The transparent membrane covering the eyeball and attached to the eyelids

Connective tissue Any animal tissue that provides support, packing and insulation between the organs of the body; usually the cells are found in a large amount of matrix

Constipation Disease in which it is difficult to release faeces

Constrict To become narrower

Continental drift A theory explaining how the major land masses of earth have moved over time due to plate tectonics

Control The part of an experiment where the manipulated variable is controlled or is missing so the experimenter can check that the variable is causing the effect

Convex With a surface that curves outwards towards the edge

Convoluted Very highly folded and tangled up

Co-ordination Causing separate parts to work together as one unit

Cornea The transparent part of the sclera at the front of the eye

Coronary artery One of the arteries that surround the heart and feed its muscles

Corpus callosum Bundle of nerve fibres making the connection between the right and left cerebral hemispheres

Corolla The collective term for all the petals of one flower

Cortex The outer region of an organ such as the kidney

Cotyledon The part of the embryo of a plant used to provide food; flowering plants have either one (monocots) or two (dicots) in each seed

Counter current A system where two liquids flow close to each other in opposite directions

Cranial nerves Peripheral nerves that come from the brain part of the central nervous system

Cretinism A condition of having a poorly developed brain and body due to lack of thyroxin

Cristae Folds on the inner membrane of a mitochondrion

Cross pollination The transfer of pollen from the male part of one flower to the female part of another flower of the same species

Cupula Jelly-like structure in the ampulla which moves when the head is moved

Cusp The place where two curved surfaces meet

Cuticle The waxy, waterproof outer layer of a plant organ such as the shiny coating on a leaf

Cytoplasm All the living substance of a cell except for the nucleus; it includes the other

organelles.

Cytosol The liquid part of the cell which is the cytoplasm without its membraneous organelles

Dark phase (stage) The part of the process of photosynthesis that is independent of light; when carbon dioxide is fixed and then reduced to make carbohydrate

Data Known facts which can be used for analysis and interpretation

Deamination Removing the amino group (-NH2) from an amino acid to leave C, H and O only

Deficiency When there is not enough of something to do the job properly

Denature When a protein loses its shape due to changes in acidity or to high temperatures; then it can no longer carry out its job

Dendrite A shorter extension of a nerve cell; bringing the impulse to the cell body

Dental formula A statement of the number of each type of teeth in one half of the upper and lower jaw of a mammal species