[Unit 4.4] Genetic Diversity and Adaptation

Question 1

name some mutagenic agents

Answer 1

ionising radiation
UV light
Carcinogens

Question 2

define genetic diversity

Answer 2

total number of different alleles within a population

Question 3

define allele frequency

Answer 3

how often a particular allele occurs within a population

Question 4

define reproductive success

Answer 4

how successful organisms are at reproducing.

Question 5

what is natural selection

Answer 5

process leading to evolution
changing allele frequency over generations
results in species becoming better adapted

Question 6

what are the three types of adaptation

Answer 6

anatomical - structural (beak shape)
physiological - chemical reaction (venom)
behavioural - expressed behaviour (penguins huddling)

Question 7

what are the three types of selection

Answer 7

directional
stabilising
disruptive

Question 8

what is directional selection

Answer 8

• one of the extremes has a selection advantage
• occurs when there is a change in environment
• modal trait changes

Question 9

what is stabilising selection

Answer 9

• modal trait has selective advantage
• occurs when there is no change in environment.
• modal trait remains the same
• standard deviation decreases as individuals with extreme trait decreases.

Question 10

describe how antibiotic resistance bacteria comes to be

Answer 10

• mutation enabled production of new protein (penicillinase)
• when they are treated, they have survival advantage
• they can then divide by binary fission
• population of resistant bacteria builds up
• allele frequency that enables production of penicillinase increases.