topic 4 key terms

Question 1

Captive breeding programme

Answer 1

Breeding wild animals in a safe environment like a zoo or sanctuary to increase population size.

Question 2

Double blind trial

Answer 2

A drug trial is completed where neither the researcher or patient know which drug is a placebo and which is the working drug in order to remove researcher bias.

Question 3

Phase 1 clinical trial

Answer 3

A clinical trial where the drug is tested on a small group of healthy volunteers to test for safety and side effects.

Question 4

Phase 2 clinical trial

Answer 4

A clinical trial where the drug is tested on a small group of patients suffering from the disease to determine how effective the drug is and what the most appropriate dose is.

Question 5

Phase 3 clinical trial

Answer 5

The final phase in clinical trials where the drug is tested to observe its effects in a much larger group of patients

Question 6

Placebo

Answer 6

A replica of the drug being tested that is indistinguishable from the real drug yet it exerts no effects on the patient whatsoever.

Question 7

Reintroduction programmes

Answer 7

Releasing animals from captivity back into the wild in a controlled and safe manner.

Question 8

William Withering’s digitalis soup

Answer 8

One of the first examples of drug testing where the correct dose of digitalis from the poisonous foxglove plant to treat heart disease was determined by William Withering

Question 9

Calcium ion

Answer 9

A type of ion with the formula Ca2+ which is used to form pectins and is very important for the structure of the cell wall in plants.

Question 9

Amyloplasts

Answer 9

Organelles found in the cytoplasm of plant cells that are used to store starch

Question 10

Cellulose

Answer 10

A polysaccharide made of beta glucose monomers joined by β-1,4 bonds that is used as a structural polysaccharide which provides strength to plant cell walls.

Question 11

Cell vacuole

Answer 11

A membrane bound structure found in plant cells that contains cell sap.

Question 12

Cell wall

Answer 12

A permeable layer that surrounds plant, algae and fungi cells made of polysaccharides which provides strength to the cell.

Question 13

Chloroplast

Answer 13

An organelle found in plants and algae that is the site of photosynthesis.

Question 14

Magnesium ions

Answer 14

A type of ion with the formula Mg2+ which is needed for chlorophyll to function so that plants can carry out photosynthesis.

Question 15

Middle lamella

Answer 15

A layer made up of pectins which joins the cell walls of adjacent plant cells together.

Question 16

Nitrate ion

Answer 16

A type of ion with the formula NO3 -which is taken up by plants from the soil and is used to make proteins.

Question 17

Phloem sieve tubes

Answer 17

Living phloem cells joined together to create a long tube for the efficient transport of assimilates.

Question 17

Phloem

Answer 17

A tissue found in plants which is specialised for the transport of assimilates from their site of production to different parts of the plant where they are needed.

Question 18

Pits

Answer 18

Thin sections of the cell wall that allow for the exchange of water and minerals between adjacent cells.

Question 19

Plasmodesmata

Answer 19

Cytoplasmic bridges between adjacent plant cells that allow the transport of molecules between the cells.

Question 20

Sclerenchyma

Answer 20

Plant tissue made up of cells with thickened cell walls which is used for strength and support.

Question 21

Tonoplast membrane

Answer 21

The membrane which surrounds the cell vacuole.

Question 22

Xylem

Answer 22

A tissue found in plants which is specialised for the transport of water and dissolved
minerals up the plant.

Question 23

Adaptation

Answer 23

The changes organisms undergo to become more suited to their environment.

Question 24

Anatomical adaptations

Answer 24

Changes to the physical features of an organism that help it cope with factors in its environment.

Question 25

Behavioural adaptations

Answer 25

The ways in which an organism acts differently to cope with factors in its environment.

Question 26

Biodiversity

Answer 26

A measure of the variety of life in an area.

Question 27

Classification

Answer 27

A means of organising the variety of life based on relationships between organisms using differences and similarities in phenotypes and in genotypes.✢

Question 28

Endemism

Answer 28

A species which only exists in a certain area.

Question 29

Evolution

Answer 29

The change in a population’s inherited characteristics over time.

Question 30

Hardy-Weinberg principle

Answer 30

A principle that states that the frequency of alleles in a population will not change over time unless evolutionary factors are present. It can be used to calculate the frequencies of the other two genotypes when given the frequency of one genotype using the equation given below: p^2 + 2pq + q^2 = 1 p^2 = Frequency of homozygous dominant 2pq = Frequency of heterozygous q^2 = Frequency of homozygous dominant

Question 31

p^2

Answer 31

Frequency of homozygous dominant

Question 32

2pq

Answer 32

Frequency of heterozygous

Question 33

q^2

Answer 33

Frequency of homozygous dominant

Question 34

Heterozygosity index (H)

Answer 34

A measure of the proportion of a population which is heterozygotic which can be calculated using the following equation: H = Number of heterozygous / Number of individuals in the population

Question 35

Index of diversity (D)

Answer 35

A measure of the diversity of a population which takes into account the number and abundance of a species and can be used to compare different habitats - it is calculated using the following equation: D = N(N-1) / sum of n(n-1) N = Total number of organisms n = Total number of organisms of the species of interest

Question 36

N

Answer 36

Total number of organisms

Question 37

n

Answer 37

Total number of organisms of the species of interest

Question 38

Natural selection

Answer 38

The phenomenon seen where better adapted organisms are able to survive and reproduce which causes the population to become better adapted over time.

Question 39

Niche

Answer 39

The position occupied by an organism in its ecosystem.

Question 40

Physiological adaptations

Answer 40

The internal body changes that an organism undergoes to cope factors in its environment.

Question 41

Reproductive isolation

Answer 41

The inability of some organisms of a species to breed with other members of the same species due to barriers.

Question 42

Species

Answer 42

Organisms that can breed together to produce fertile offspring.

Question 43

Species richness

Answer 43

The number of different species in a habitat.