3.4.4 Genetic diversity and adaptation

Question 1

what is genetic diversity

Answer 1

the number of different alleles of genes in a population

Question 2

what is the importance of genetic diversity

Answer 2

it allows the population to adapt to changes in environment

Question 3

what factors can increase genetic diveristy

Answer 3

mutations in DNA and new alleles are formed
different alleles are being introduced

Question 4

what is a gentic bottleneck

Answer 4

an event that causes a big reduction in a population

Question 5

what are the principles of natural selection? (5 marks)

Answer 5

• variation of alleles due to DNA mutation
• there is a selection pressure/ change in environment
• those with advantageous alleles are able to survive and reproduce
• advantageous alleles are passed onto offsprings
• allelic frequency increases over many generations

Question 6

what type of environment does directional selection occur in?

Answer 6

a changing one

Question 7

what is directional selection

Answer 7

• a change in the environment
• selection pressure accts on one side of the mean
• the extreme phenotype can survive and reproduce
  -mean phenotype changes

Question 8

what type of environment is present in stabilising selection

Answer 8

a stable environment

Question 9

explain what happens during stabilisng selection

Answer 9

a stable environment
- selection pressure acts on either side of the mean
- extreme phenotypes are less likely to survive and reproduce

Question 10

what happens to the mean phenotype in stabilising selection

Answer 10

remains the same

Question 11

what is an example of stabilisng selection

Answer 11

baby birth weights

Question 12

whatt does natural selection result in

Answer 12

better adapted species

Question 13

what are anatomical adaptations

Answer 13

structural features of an organism which increases its chances of survival w

Question 14

what is an example of an anatomical adaptation

Answer 14

whales have thick layers of bubbler (fat) which keeps them warm

Question 15

what are physiological adaptations

Answer 15

processes that occur inside the body which increases the chances of survival

Question 16

what is an example of a physiologiccal adaptation

Answer 16

when bears hibernate, lower metabolism to conserve energy

Question 17

what are behavioural adaptations

Answer 17

the way an organism acts which increases its chances of survival

Question 18

what is an example of a behavioural adaptation

Answer 18

possums play dead when they are being threatened by a redator

Question 19

what is a species

Answer 19

two organisms that are able to produce fertile offsprings

Question 20

when mating why are offsprings from 2 different species infertile

Answer 20

• there are odd number of chromosomes
  so meiosis cant be performed

Question 21

what is courtship behaviour

Answer 21

when organisms attract a mate of the same species

Question 22

explain how courtship behaviour is species specific

Answer 22

only members of the same species will respond to the courtship behaviour

Question 23

what does courtship behaviour prevent

Answer 23

prevents interbreeding

Question 24

what 4 things increase genetic variation

Answer 24

• independant segration and crossing over of homologus chromosomes
• random fertilisation
  -mutation

Question 25

what is chromosome non-disjunction

Answer 25

the failure of chromosomes to separate

Question 26

how mutations arise in chromosomes

Answer 26

spontaneously by chromosome non-disjunction by meiosis

Question 27

what is a phylogenic classification system

Answer 27

arranges species into groups based on their evolutionary origins

Question 28

what is a hierarchy

Answer 28

small groups are placed within larger groups theres no overlap between each group

Question 29

what is each group called in hierachy

Answer 29

taxon

Question 30

what are the taxa groups

Answer 30

domain kingdom phylum class order family genus species

Question 31

how is each speices universally identified by

Answer 31

genus and species

Question 32

how does genome sequencing help to clarify the evolutionary relationships between organisms

Answer 32

compares the order of base sequences of the genome of different species

Question 33

how does immunology help to clarify the evolutionary relationships between organisms

Answer 33

if same antibody binds to a specific antigen that is closely related

Question 34

what is biodiversity

Answer 34

the variety of living organisms in an area

Question 35

what is species richness

Answer 35

a measure of the number of different species in a community

Question 36

what is species diversity

Answer 36

the number of different species and the number of individuals of each species within a community

Question 37

what is a habitat

Answer 37

the place where an organism lives

Question 38

what is a community

Answer 38

all the populations of different species in a habitat

Question 39

what is local biodiversity

Answer 39

the variety of species in a small habitat

Question 40

what is global biodiversity

Answer 40

the variety of species living on earth

Question 41

what does index of diversity describe

Answer 41

describes the relationship between the number of species in a community and the number of individuals in each species

Question 42

what does a high value of D suggest in index diversity

Answer 42

theres more diversity

Question 43

what reduces biodiversity

Answer 43

farming

Question 44

what are the affects of pesticides on reduction of biodiversity

Answer 44

the chemicals kills organisms that feed on organisms that feed on crops.

Question 45

what is monoculture

Answer 45

when one type of plant is farmed the single type reduces biodiversity cause it supports fewer organisms

Question 46

what is hedgegrow removal

Answer 46

turns lots of small fields into larger fields .

Question 47

what is woodland clearance and how does this reduce biodiversity

Answer 47

reduces the number of trees and the number of different tree species destroys habitats, species lose their shelter causes thee other species to migrate