Genetic diversity and adaptations

Question 1

What is genetic diversity?

Answer 1

Number of different alleles of a gene in a population

Question 2

define population

Answer 2

group of interbreeding individuals of the same species

Question 3

natural selection

Answer 3

Variation of alleles exists in population due to random DNA mutations
Selection pressure(change in environment)
Those with advantageous allele have increased chance of survival and reproduction
Those reproducing pass advantageous allele to offspring
Frequency of advantageous allele and characteristic increases in the population
Over many generations it leads to change in gene pool
Evolution=change in allele frequency over time)

Question 4

Explain the process of directional selection e.g. antibiotic resistance in bacteria

Answer 4

Change to the environment
Selection pressure acts one side of the mean
One extreme phenotype more likely to survive and reproduce
e.g. Bacteria with gene for antibiotic resistance
Mean phenotype changes

Question 5

Describe the process of stabilising selection e.g. human birth weight

Answer 5

Stable environment
Selection pressure acts either side of the mean
Both extremes of phenotype less likely to survive and reproduce (very small or very large babies)
Mean phenotype remains the same

Question 6

state the 3 types of adaptation that arises from Natural selection

Answer 6

Anatomical
Physiological
Behavioural

Question 7

anatomical adaptations

Answer 7

Structural features of organisms body / observed structures E.g. whales
thick layer of blubber helps keep warm in cold sea

Question 8

physiological adaptations

Answer 8

Processes inside the body E.g. brown bears hibernate in the winter, lower metabolism to conserve energy so they don’t need to look for food when its scarce

Question 9

behavioural adaptations

Answer 9

Ways an organism acts E.g. possum plays dead if they’re being threatened by a predator, to escape attack