Genetic Information, Variation and Relationships Between Organisms: Genetic Diversity & Adaptations - Natural Selection

Question 1

What is natural selection?

Answer 1

• Process where an allele becomes more common in a population because it codes for a characteristic that makes an organism more likely to survive, reproduce and pass on its gene to its offspring

Question 2

How can genetic mutations lead to natural selection?

Answer 2

• Mutations may result in a new allele being formed
• Some mutations can produce beneficial characteristics to an organism, helping them to survive and reproduce
• The allele that codes this characteristic, increases the organism’s chance of survival so its frequency within the population can increase

Question 3

What process does natural selection lead to?

Answer 3

• Evolution

Question 4

Define the term evolution

Answer 4

• The gradual change in species over time

Question 5

What are the different types of adaptations natural selection can lead to?

Answer 5

• Behavioural adaptations
• Physiological adaptations
• Anatomical adaptations

Question 6

Define the term behavioural adaptation

Answer 6

• Ways an organism acts that increase its chance of survival

Question 7

Define the term physiological adaptations

Answer 7

• Processes inside an organisms body that increase its chance of survival

Question 8

Define the term anatomical adaptation

Answer 8

• Structural features of an organism’s body that increase its chance of survival

Question 9

What are the different types of natural selection?

Answer 9

• Directional selection
• Stabilising selection
• Disruptive selection

Question 10

What is directional selection?

Answer 10

• Where individuals with alleles for characteristics of an extreme type are more likely to survive and reproduce
• Could be in response to an environmental change
• E.g antibiotic resistance in bacteria

Question 11

What is stabilising selection?

Answer 11

• Where individuals with alleles for characteristics toward the middle of the range are more likely to survive and reproduce
• Occurs in an unchanging environment
• E.g human birth weights

Question 12

What is disruptive selection?

Answer 12

• Where individuals with alleles for characteristics for both extremes are favoured and where alleles in the middle range aren’t favoured