definitions

Question 1

Sustainable Resources

Answer 1

A sustainable resource is one which is produced as rapidly as it is removed from the environment so that it does not run out.

Question 2

Sustainable development

Answer 2

development providing for the needs of an increasing human population without harming the environment.

Question 3

Trophic level

Answer 3

position of an organism in a food chain, food web, pyramid of numbers or pyramid of biomass

Question 4

population

Answer 4

a group of organisms of one species, living in the same area, at the same time

Question 5

community

Answer 5

all of the populations of different species in an ecosystem

Question 6

ecosystem

Answer 6

unit containing the community of organisms and their environment, interacting together, e.g. a decomposing log, or a lake

Question 7

genetic engineering

Answer 7

changing the genetic material of an organism by removing, changing or inserting individual genes

Question 8

chromosome

Answer 8

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

Question 9

inheritance

Answer 9

transmission of genetic information from generation to generation

Question 10

gene

Answer 10

length of DNA that codes for a protein

Question 11

allele

Answer 11

version of a gene

Question 12

haploid and diploid nucleus

Answer 12

Define a haploid nucleus as a nucleus containing a single set of unpaired chromosomes, e.g. in gametes
Define a diploid nucleus as a nucleus containing two sets of chromosomes, e.g. in body cells

Question 13

mitosis

Answer 13

nuclear division giving rise to genetically identical cells (details of stages are not required)

Question 14

meiosis

Answer 14

Meiosis is nuclear division that gives rise to four genetically different cells.

reduction division in which the chromosome number is halved from diploid to haploid resulting in genetically different cells

Question 15

genotype and phenotype

Answer 15

Define genotype as the genetic make-up of an organism in terms of the alleles present
Define phenotype as the observable features of an organism

Question 16

homozygous and heterozygous

Answer 16

Define homozygous as having two identical alleles of a particular gene
Define heterozygous as having two different alleles of a particular gene

homozygous XX
heterozygous XY

Question 17

dominant and recessive

Answer 17

Define dominant as an allele that is expressed if it is present
Define recessive as an allele that is only expressed when there is no dominant allele of the gene present

Question 18

sex-linked characteristic

Answer 18

characteristic in which the gene responsible is located on a sex chromosome and this makes it more common in one sex than in the other

Question 19

asexual reproduction

Answer 19

production of genetically identical offspring from one parent

Question 20

sexual reproduction

Answer 20

fusion of the nuclei of two gametes to form a zygote and production of offspring that are genetically different from each other

Question 21

fertilisation

Answer 21

fusion of gamete nuclei

Question 22

self & cross-pollination

Answer 22

transfer of pollen from anther to stigma on the same plant

cross-pollination
transfer of pollen from anther to stigma on a different plant of the same species

Question 23

pollination

Answer 23

transfer of pollen from anther to the stigma

Question 24

STI

Answer 24

sexually transmitted infection
infection that is transmitted via body fluids through sexual contact

Question 25

synapse

Answer 25

junction between two neurons

Question 26

sense organs

Answer 26

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

Question 27

hormone

Answer 27

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

Question 28

homeostasis

Answer 28

maintenance of a constant internal environment

Question 29

gravitropism and phototropism

Answer 29

Define gravitropism as a response in which parts of a plant grow towards or away from gravity Define phototropism as a response in which parts of a plant grow towards or away from the direction from which light is coming

Question 30

circulatory system

Answer 30

circulatory system as a system of blood vessels with a pump and valves to ensure one-way flow of blood

Question 31

Transpiration

Answer 31

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

Question 32

Translocation

Answer 32

Translocation is the movement of sucrose and amino acids in the phloem from sources to sinks.

Question 33

Osmosis

Answer 33

Osmosis is the net movement of water molecules from a region of higher water potential to a region of lower water potential, across a partially permeable membrane.

Question 34

Photosynthesis

Answer 34

Photosynthesis is the process that plants use to manufacture carbohydrates (glucose) from raw materials (carbon dioxide and water) using energy from light

Question 35

Limiting factor

Answer 35

something present in the environment in such short supply that it restricts life

Question 36

Decomposer

Answer 36

organism that gets energy by feeding on dead/ waste material

Question 37

movement

Answer 37

action by an organism causing change of place or position

Question 38

aerobic respiration

Answer 38

series of chemical reactions in cells that uses oxygen to break down nutrient molecules to release energy glucose + 6O2 => 6CO2 + 6H2O

Question 39

anaerobic respiration

Answer 39

series of chemical reactions in cells that breaks down nutrient molecules to release energy without using oxygen glucose => lactic acid anaerobic respiration in yeast glucose => alcohol(C2H5OH) + carbon dioxide

Question 40

transmissible disease

Answer 40

disease where pathogen can be passed from one host to another

Question 41

active and passive immunity

Answer 41

Active - defence against a pathogen by the production of antibodies in the body