definitions

Question 1

absorption

Answer 1

the movement of digested food molecules through the wall of the intestine into the blood or lymph

Question 2

accommodation

Answer 2

the change of shape of the lens, in order to focus on objects at different distances

Question 3

active immunity

Answer 3

defence against a pathogen by antibody production in the body

Question 4

active site

Answer 4

the part of an enzyme molecule into which its substrate fits

Question 5

active transport

Answer 5

the movement of molecules and ions in or out of a cell through the cell membrane, from a region of their higher concentration against a concentration gradient, using energy released during respiration

Question 6

adaptation (adaptive feature)

Answer 6

a feature of an organism that helps it survive in its environment

Question 7

adaptive features

Answer 7

the inherited functional features of an organism that increase its fitness

Question 8

adipose tissue

Answer 8

tissue made up of cells in which fat is stored

Question 9

adrenaline

Answer 9

a hormone secreted by the adrenal glands, which prepares the body for “flight or fight”

Question 10

adult stem cell

Answer 10

a cell in an adult that can give rise to a limited range of specialised cells

Question 11

aerobic respiration

Answer 11

the release of a relatively large amount of energy in cells by the breakdown of nutrient molecules in the presence of oxygen

Question 12

allele

Answer 12

any of two or more alternative forms of a gene

Question 13

alimentary canal

Answer 13

part of the digestive system; a long tube running from mouth to anus

Question 14

alveolus (plural: alveoli)

Answer 14

an air sac in the lungs, where gas exchange occurs

Question 15

amino acids

Answer 15

molecules that can link together in long chains to form proteins; they contain carbon, hydrogen, oxygen and nitrogen, and sometimes sulfur

Question 16

amniotic fluid

Answer 16

fluid secreted by the amnion, which supports and protects a developing fetus

Question 17

amylase

Answer 17

an enzyme which breaks down starch to maltose

Question 18

anaerobic respiration

Answer 18

the release of a relatively small amount of energy by the breakdown of nutrient molecules in the absence of oxygen

Question 19

anatomy

Answer 19

the detailed body structure of an organism

Question 20

anther

Answer 20

the part of a stamen in which pollen is produced

Question 21

antibiotic

Answer 21

a drug that kills bacteria in the human body, without damaging human cells

Question 22

antibodies

Answer 22

chemicals secreted by lymphocytes, which attach to antigens and help to destroy them

Question 23

antigens

Answer 23

chemicals on the surfaces of pathogens, which are recognised as foreign by the body

Question 24

artery

Answer 24

a blood vessel that carries blood away from the heart

Question 25

artificial selection

Answer 25

the choice by a farmer or grower of only the “best” parents to breed, generation after generation

Question 26

asexual reproduction

Answer 26

the process resulting in the production of genetically identical offspring from one parent

Question 27

assimilation

Answer 27

the movement of digested food molecules into the cells of the body where they are used, becoming part of the cells

Question 28

atrioventricular valves

Answer 28

valves between the atria and ventricles in the heart that prevent blood flowing from the ventricles to the atria

Question 29

auto-immune disease

Answer 29

a disease caused by a persons own immune system attacking parts of their body

Question 30

auxin

Answer 30

a plant hormone that causes cells to elongate

Question 31

axon

Answer 31

a nerve fibre that conducts impulses away from the cell body

Question 32

balanced diet

Answer 32

a diet containing some of each of the different types of nutrients, in a suitable quantity and proportions

Question 33

base

Answer 33

in DNA, one of four substances (A, C, G and T) that make up the genetic code

Question 34

bile

Answer 34

a liquid made in the liver, stored in the gall bladder and emptied into the small intestine, where it helps to emulsify fats

Question 35

binomial

Answer 35

a two-word Latin name for a species of organism

Question 36

biuret test

Answer 36

a test for protein

Question 37

breathing

Answer 37

muscular movements which cause air to move into and out of the lungs

Question 38

bronchioles

Answer 38

the small tubes into which the bronchi branch

Question 39

bronchus (plural: bronchi)

Answer 39

one of the two tubes into which the trachea branches, carrying air into each lung

Question 40

capillaries

Answer 40

a tiny blood vessel that delivers blood to tissues

Question 41

carbohydrase

Answer 41

an enzyme that catalyses the breakdown of carbohydrates

Question 42

carbohydrates

Answer 42

starches and sugars

Question 43

carcinogen

Answer 43

a substance which increases the risk of a persons body developing cancer

Question 44

cardiac muscle

Answer 44

the muscle of which the heart is made

Question 45

carnivore

Answer 45

an animal that gets its energy by eating other animals

Question 46

carpel

Answer 46

the female part of a flower

Question 47

catalase

Answer 47

an enzyme found in almost all living tissues, which catalyses the breakdown of hydrogen peroxide to water and oxygen

Question 48

catalyst

Answer 48

a substance that speeds up a chemical reaction and is not changed by the reaction

Question 49

cell membrane

Answer 49

a very thin layer of fat and protein that surrounds every living cell

Question 50

cell sap

Answer 50

a solution of sugars and other substances inside the vacuole of a plant cell