Genetic diversity and adaptation

Question 1

genetic diversity

Answer 1

number of different alleles in a population

allows natural selection to occur

Question 2

allele frequency

Answer 2

proportion of individuals who have a copy of an allele

change over time in response to selection pressure due to natural selection

Question 3

natural selection process

Answer 3

random mutation of gene occurs and results in new alleles of a gene
new allele may be favourable to some in a population
individuals with advantageous allele are more likely to survive and reproduce
allele passed on through generations
over many generations, allele increases in frequency in the population

Question 4

directional selection

Answer 4

change in environment occurs and one extreme is favoured to survive and reproduce
on graph- curve is moved to one side
changes selection pressure so different individuals have an advantage

Question 5

antibiotic resistance

Answer 5

mutation occurs that mean one bacteria are resistant to antibiotic
they will have huge selective advantage over the other bacteria eg in a hospital
they won’t be killed by antibiotics and other bacteria will
will be able to reproduce and colonise the environment without any competition
DS

Question 6

stabilising selection

Answer 6

keeps allele frequencies constant over time
individuals with alleles for characteristics towards the middle of the range are more likely to survive and reproduce
selection against extremes
occurs when environment isn’t changing so the individuals do not need to change

Question 7

human birth weight

Answer 7

babies with very low or very high birth weight are less likely to survive and reproduce
won’t pass on their alleles for high or low birth weight
allele frequency will decrease in the population over time over time
SS

Question 8

adaptations

Answer 8

certain alleles may make an individual more suited to their environment- adaptations
natural selection selects for favourable alleles that cause adaptations

Question 9

anatomical adaptations

Answer 9

physical/structural features

eg white fur of polar bear to make it camouflaged

Question 10

behavioural adaptations

Answer 10

the way an organism behaves to increase chance of survival

eg possums play dead when they are being attacked/threatened

Question 11

physiological adaptations

Answer 11

biological processes within the organism

eg bears hibernate in the winter by lowering rate of metabolism to conserve energy