definitions - set 3

Question 1

egg

Answer 1

a female gamete

Question 2

embryo

Answer 2

a young organism before birth, and before all the body organs have formed

Question 3

embryonic stem cell

Answer 3

a cell in an embryo that is capable of giving rise to all types of specialised cell

Question 4

emphysema

Answer 4

a disease in which the walls of the alveoli in the lungs break down, reducing the surface area for gas exchange

Question 5

emulsification

Answer 5

breaking large globules of fat into tiny droplets, so that they mix easily with water

Question 6

endocrine glands

Answer 6

the ductless glands that secrete hormones into the blood and together make up the endocrine system

Question 7

endothermic

Answer 7

able to internally regulate body temperature; the body temperature is independent of the temperature of the environment

Question 8

enhanced greenhouse effect

Answer 8

the increase in the greenhouse effect caused by the addition of more greenhouse gases to the atmosphere

Question 9

enzymes

Answer 9

proteins that function as biological catalysts

Question 10

epidermis (mammal)

Answer 10

the outer layer of the skin

Question 11

epidermis (plant)

Answer 11

a tissue made up of a single layer of cells which covers the top and bottom of a leaf, and the outside of the stem and root

Question 12

excretion

Answer 12

removal from organisms of the waste products of metabolism (chemical reactions in cells including respiration) toxic materials and substances in excess of requirements

Question 13

exponential phase

Answer 13

(log phase) the stage in population growth when numbers increase exponentially

Question 14

evolution

Answer 14

the change in adaptive features of a population over time, as a result of natural selection

Question 15

F1 generation

Answer 15

the offspring from a parent homozygous for a dominant allele and a parent homozygous for the recessive allele

Question 16

fermentation

Answer 16

the breakdown of glucose by yeast, using anaerobic respiration; it produces carbon dioxide and alcohol

Question 17

fertilisation

Answer 17

the fusion of the nuclei of two gametes

Question 18

fetus

Answer 18

a young organism before birth, once all the body organs have formed

Question 19

fibrin

Answer 19

an insoluble protein that forms fibres that help in blood clotting

Question 20

fibrinogen

Answer 20

a soluble protein that is converted to insoluble fibrin when blood clots

Question 21

filament

Answer 21

the stalk of the stamen

Question 22

fitness

Answer 22

the probability of an organism surviving and reproducing in the environment in which it is found

Question 23

flaccid

Answer 23

a term used to describe a cell that has lost a lot of water, becoming soft

Question 24

follicle

Answer 24

a space inside an ovary in which an egg develops

Question 25

food chain

Answer 25

a chart showing the flow of energy (food) from one organism to the next beginning with a producer (e.g. mahagony tree - caterpillar - song bird - hawk)

Question 26

food web

Answer 26

a network of interconnected food chains showing the energy flow through part of an ecosystem

Question 27

fovea

Answer 27

the part of the retina where cones are most tightly packed

Question 28

fruit

Answer 28

an ovary of a plant after fertilisation; it contains seeds

Question 29

FSH

Answer 29

follicle stimulating hormone; a hormone secreted by the pituitary gland which causes the development of eggs in the ovaries

Question 30

fully permeable

Answer 30

able to let most substances pass through

Question 31

gametes

Answer 31

sex cells, e.g. eggs and sperm

Question 32

gas exchange

Answer 32

the entry of oxygen into and organisms body, and the loss of carbon dioxide

Question 33

gene

Answer 33

a length of DNA that is the unit of heredity and codes for a specific protein

Question 34

gene mutation

Answer 34

a change in the base sequence of DNA

Question 35

genetic diagram

Answer 35

the conventional way to set out a genetic cross

Question 36

genetic engineering

Answer 36

taking a gene from one species and putting it into another species

Question 37

genotype

Answer 37

the genetic makeup of an organism in terms of the alleles present (e.g. Tt or GG)

Question 38

genus (plural: genera)

Answer 38

a group of similar and related species

Question 39

glomerulus

Answer 39

a tangle of blood capillaries in a Bowman's capsule in the kidney

Question 40

glucagon

Answer 40

a hormone secreted by the pancreas, which increases blood glucose level

Question 41

glycogen

Answer 41

the polysaccharide that is used as an energy store in animal cells and fungi

Question 42

goblet cells

Answer 42

cells which secrete mucus

Question 43

gravitropism

Answer 43

a response in which a plant grows towards or away from gravity

Question 44

greenhouse effect

Answer 44

the warming effect of carbon dioxide, methane and other greenhouse gases, on the Earth

Question 45

growth

Answer 45

a permanent increase in size and dry mass by an increase in cell number or cell size or both

Question 46

guard cell

Answer 46

one of the two sausage-shaped cells in the epidermis in plants, between which there is a hole called stoma; the guard cells can change shape to open and close the stoma

Question 47

habitat

Answer 47

the place where an organism lives

Question 48

haploid

Answer 48

having one set of chromosomes

Question 49

hepatic portal vein

Answer 49

a blood vessel that transports blood from the digestive system to the liver

Question 50

hervibore

Answer 50

an animal that gets its energy by eating plants