Definitions

Question 1

Define Active Transport.

Answer 1

Active transport is the process In which energy is used to move the substance across a membrane against its concentration gradient.
I.e from higher to lower cont

Question 2

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Answer 2

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Question 3

Define Osmosis.

Answer 3

Osmosis is the net movement of water molecules from a solution of higher to lower water potential through a p.p membrane.

Question 4

Define differentiation.

Answer 4

Differentiation is the process by which a cell becomes specialised for a specific function.

Question 5

Define ‘Tissue’

Answer 5

A tissue is a group of cells with similar structures which work together to perform a specific function.

Question 6

Define Diffusion.

Answer 6

Diffusion is the net movement of particles from a region of higher concentration to lower concentration down a concentration gradient.

Question 7

Define Carbohydrates.

Answer 7

Carbs are organic moleqs made up of C/H/O. The H and O atoms are present in 2:1

Question 8

Define Condensation

Answer 8

A condensation rxn is a chemical rxn in which 2 simple moleqs join tgt to form a larger moleq with removal of 1 moleq of H²O

Question 9

Define hydrolysis

Answer 9

Hydrolysis is a rxn in which a H²O moleq is needed to break up a larger moleq into smaller moleq

Question 10

Define fats.

Answer 10

Fats are organic moleqs made up of C/H/O; but contain less O:H as compared to carbs

Question 11

Define Protein

Answer 11

Proteins are organic moleqs made up of elements C/H/O/N. S may be present.

Question 12

Define Enzyme

Answer 12

Enzymes are proteins that function as biological catalysts. They can alter or speed up chemical reactions. They are unchanged at the end of the reaction.

Question 13

Define Digestion

Answer 13

Digestion is the process by which large food molecules are broken down into smaller, soluble molecules that can be absorbed into the body cells.

Question 14

Define absorption

Answer 14

Absorption is the process whereby digested food substances are absorbed into the body cells.

Question 15

Define Assimilation

Answer 15

Assimilation is the process whereby some of the absorbed food substances are converted into new protoplasm or used to provide energy.

Question 16

Define Deamination.

Answer 16

Delamination is the process by which amino groups are removed from amino acids and converted into urea.

Question 17

Define respiration

Answer 17

Respiration is the oxidation of food moleqs with the release of energy in living cells.

Question 18

Define aerobic respiration.

Answer 18

Aerobic respiration us the oxidation of food moleqs in presence of oxygen with the release of a large amount of energy. CO² and H²O are released as waste products.

Question 19

Define Anaerobic Respiration

Answer 19

Oxidation of food moleqs in the absence of oxygen. Releases less energy then aerobic respiration.

Question 20

Define excretion

Answer 20

Excretion is the process by which metabolic waste products and toxic substances are removed from the body of an organism.

Question 21

Define homeostasis

Answer 21

Homeostasis is the maintenance of a constant internal environment within narrow limits

Question 22

Define negative feedback

Answer 22

Negative feedback is a sequence of events to bring about an opposite effect to changes detected to return in to normal.

Question 23

Define reflex action

Answer 23

Reflex actions are an immediate response into a specific stimulus without conscious control.

Question 24

Focusing

Answer 24

Focusing/Accommodation is the adjustment of the lens of the eye so that clear images of objects at different distances are formed on the retina.

Question 25

Hormones

Answer 25

A hormone is a chemical substance produced in minute qtys by an endocrine gland. Transporter in the bloodstream to target organs where they exert its effects. After hormones have performed their functions they are destroyed by the liver.

Question 26

Endocrine Glands

Answer 26

Endocrine glands are ductless glands that secrete hormones directly into the bloodstream to act on target organs.

Question 27

Define Gene.

Answer 27

A DNA moleq may carry gene along its length. A gene is a sequence of DNA nucleotides that control the formation of a single polypeptide. And is a unit of inheritance borne on a particular locus of a chromosome.

Question 28

Define genetic engineering.

Answer 28

Genetic engineering is a technique used to the transfer genes from 1 organism to another. Individual genes may be cut off from the veils of one organism and inserted into the cells of another organism of the same/diff species. The transferred gene should express itself in the recipient organism.

Question 29

Define mitosis

Answer 29

Mitosis is a form of nuclear division that produces daughter nuclei containing the same number of chromosomes as the parent nucleus. The daughter nuclei are genetically equal.

Question 30

Define Meiosis

Answer 30

Meiosis is a form of nuclear division that produces daughter nuclei containing half the number of chromosomes as the parent nucleus.

Question 31

Monohybrid Inheritance

Answer 31

Inheritance involving only one pair of contrasting traits.

Question 32

Codominance

Answer 32

Co-dominance results when the 2 alleles containing a trait both express themselves in the heterozygous condition.

Question 33

Mutation

Answer 33

Mutation is a sudden random change in the structure of a gene or the number of chromosomes.

Question 34

Define PS

Answer 34

PS is the process in which light energy absorbed by chlorophyll is transformed into chemical energy. The chemical energy is used to synthesise carbohydrates from H²O and CO². H²O and CO² are the raw materials for photosynthesis. Oxygen is released during the process.

Question 35

Define Translocation.

Answer 35

The transport of manufactured food substances such as sugars and amino acids in plants is known as translocation.

Question 36

Define Transpiration.

Answer 36

Transpiration is the loss of water vapour from a plant, mainly through the stomata of the leaves.