4 Genetics - Natural Selection

Question 1

What is natural selection?

Answer 1

The process driving evolution, the better adapted to the environment are more likely to survive and breed.

Question 2

What are 2 types of selection?

Answer 2

• Stabilising selection (favours the mean, normal distribution)
• Directional selection (favours one side of the mean)

Question 3

Whats an example of directional selection?

Answer 3

Antibiotic resistance, vertical transmission
- Binary fission occurs, antibiotic resistance mututation happens, these are better adapted to survive and more likely to reproduce as they have the advantageous phenotype, therefore the allele increases this is because they have an extreme allele which is well suited to their environment

Question 4

Example of stabilising selection

Answer 4

birthweigh of babies
underweight - can’t self thermoregulate
overweight - high blood pressure, complications during birth

Question 5

Types of adaptation

Answer 5

• Anatomical (Mole: very good hearing, large paws for digging)
• Physiological (Tuna: high respiration rate)
• Behavioural (Possum: playing dead when exposed to threats)

Question 6

Genetic diversity meaning

Answer 6

The total number of alleles in a population

Question 7

Population meaning

Answer 7

Group of individuals of the same species that live in the same place

Question 8

What are some selection pressures?

Answer 8

• Disease
• Predation
• Competition for resources

Question 9

What selection process is common within stable environments?

Answer 9

Stable selection, under regular circumstances, more extreme phenotypes are less sucessful and distribution will maintain from one generation to the next

Question 10

Stabilising Selection

Answer 10

Individuals with characteristics toward the middle of the range are more likely to survive and reproduce, this occurs when the environment does not change