ESTAS 2

Question 1

transpiration

Answer 1

loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata

Question 2

translocation

Answer 2

the movement of sucrose and amino acids in phloem:
– from regions of production (source)
– to regions of storage OR to regions where they are used in respiration or growth (sink)

Question 3

pathogen

Answer 3

a disease-causing organism

Question 4

transmissible

Answer 4

a disease in which the pathogen can be passed from one host to another

Question 5

active immunity

Answer 5

defence against a pathogen by antibody production in the body

Question 6

aerobic respiration

Answer 6

the chemical reactions in cells that use oxygen to break down nutrient molecules to release energy

Question 7

anaerobic respiration

Answer 7

the chemical reactions in cells that break down nutrient molecules to release energy without using oxygen

Question 8

deamination

Answer 8

the removal of the nitrogen-containing part of amino acids to form urea

Question 9

synapse

Answer 9

a junction between two neurones

Question 10

sense organs

Answer 10

groups of receptor cells responding to specific stimuli: light, sound, touch, temperature and chemicals

Question 11

hormone

Answer 11

a chemical substance, produced by a gland and carried by the blood, which alters the activity of one or more specific target organs

Question 12

homeostasis

Answer 12

the maintenance of a constant internal environment within set limits

Question 13

gravitropism

Answer 13

a response in which parts of a plant grow towards or away from gravity

Question 14

phototropism

Answer 14

a response in which parts of a plant grow towards or away from the direction from which light is coming

Question 15

drug

Answer 15

any substance taken into the body that modifies or affects chemical reactions in the body

Question 16

asexual reproduction

Answer 16

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

Question 17

sexual reproduction

Answer 17

a process involving the fusion of the nuclei of two gametes (sex cells) to form a zygote and the production of offspring that are genetically different from each other

Question 18

fertilisation

Answer 18

the fusion of gamete nuclei

Question 19

pollination

Answer 19

the transfer of pollen grains from the anther to the stigma

Question 20

self-pollination

Answer 20

the transfer of pollen grains from the anther of a flower to the stigma of the same flower or different flower on the same plant

Question 21

cross-pollination

Answer 21

transfer of pollen grains from the anther of a flower to the stigma of a flower on a different plant of the same species

Question 22

sexually transmitted infection

Answer 22

an infection that is transmitted via body fluids through sexual contact

Question 23

inheritance

Answer 23

the transmission of genetic information from generation to generation

Question 24

chromosome

Answer 24

a thread-like structure of DNA, carrying genetic information in the form of genes

Question 25

gene

Answer 25

a length of DNA that codes for a protein

Question 26

allele

Answer 26

a version of a gene

Question 27

haploid nucleus

Answer 27

a nucleus containing a single set of unpaired chromosomes, e.g. in gametes

Question 28

diploid nucleus

Answer 28

a nucleus containing two sets of chromosomes, e.g. in body cells