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Home >>Biology Dictionary >> Cartilage-Bone Replacing Bone - Cataract
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Carrier. A protein that helps in taking the particles from one side of membrane to the other.
Carrying capacity. The capacity of a particular habitat with reference to the maximum support, e.g. the maximum number of wading birds an estuary can support.
Cartilage. Skeletal tissue of vertebrates consisting of rounded cells scattered in a resilient polysaccharide-containing (proteoglycan (q.v.) matrix, with numerous collagen fibres which are very fine in hyaline cartilage, thicker in fibrous cartilage. Many become calcified by deposits of calcium phosphate. Devoid of blood-vessels in adult. A cartilage-like substance occurs in Cephalopoda (squids, octopuses), where it supports the brain.
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Cartilage-Bone (Replacing Bone).
A bone which replaces embryonic cartilage, e.g. limb bones; hip girdle; vertebral column; parts of skull such as auditory capsule.
Cartilaginous fish. A fish o the classes chondrichthyes or Elasmobranchi including the sharks, skates and rays, whose skeleton is entirely cartilaginous.
Caruncle. Warty outgrowth on seeds of a few flowering plants, e.g. castor oil, obscuring micropyle (q.v.).
Caryopsis. A dry single-seeded indehiscent fruit that differs from an achene in that the fruit wall is fused to the testa of the seed. It is the grain of cereals and grasses.
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Caste. A division found in social insects, such as the Hymenoptera (ants, bees, wasps) and the Isoptera (termites), in which the individuals are structurally and physiologically specialized to perform a particular function. For example, in honeybees there are queens (fertile females), workers (sterile females), and drones (males). There are several different castes of workers (all sterile females) among ants.
Castration. Removal of testes in lower animals.
Casual. An introduced plant that has not become established in an area but which may occur away from cultivation.
Catabolism (Katabolism). Breaking down by living things of complex organic molecules. With liberation of energy.
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Catalase
Enzyme which breaks down the poisonous substance hydrogen peroxide, formed during plant and animal metabolism, to water and oxygen, It prosthetic group, containing iron, is the same as that of haemoglobin.
Catalyst. Any substance that increases the rate of a reaction without itself participating in the reaction.
Cataphyll. A simplified leaf form, e.g. a bud scale, cotyledon, scale leaf.
Cataract. It is an opacity of lens. It is caused by denaturation of lens, proteins due to various reasons. It results in the loss of vision and is corrected by the surgical removal of the opaque lenses and the use of spectacle with convex lenses. It can be corrected by introducing an artificial lens surgically into the eye.
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Cat kin. Kind of inflorescence.
Cattle. A domesticated animal, usually oxen, but a term often extended to include sheep and pigs.
Caudad. Towards the tail.
Caudal. Concerning the tail.
Cauliflory. Production of flowering shoots on older, thickened, leafless branches or main trunk. Common among angiosperm tree of lower stories of canopy in tropical forests, e.g. cocoa.
Cauline. Belonging to the stem or arising from it.
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Cell
The structural and functional unit of all living – organisms. Cell size varies, but most cells are microscopic (average diameter 0.01-0.1mm). Cells may exist as independent units of life, as in bacteria and protozoans, or they may from colonies or tissues, as in all higher plants and animals. Each cell consists of a mass of protein material (see protoplasm) that is differentiated into a jelly-like substance (see cytoplasm) and a nucleus, which contains DNA.
Casparian strip
A band of suberized material around the radial walls of the individual cells of the endodermis. It is impervious to water.
Cathepsin
Several intracellular proteolytic enzymes, normally situtated in lysosomes.
The protoplasm is bounded by a cell membrane, which in plant and bacterial cells is surrounded by a cell wall. There are two main types of cells. Prokaryotic cells (bacteria and blue-green algae) are the more primitive.
The nuclear material is not bounded by a membrane and chemicals involved in cell metabolism are associated with the cell membrane. Reproduction is asexual and involves simple cell cleavage.
In eukaryotic cells the nucleus is bounded by a nuclear membrane and the cytoplasm is divided by membranes into a system of interconnected cavities and separate compartments (organelles), e.g. mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and ribosomes. Reproduction can be either asexual (see mitosis) or sexual (see meiosis). Plants and animals consist of eukaryotic cells but plants cells possess chloroplasts and other plastics and bear a rigid cellulose cell wall.
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