Component 2.1 - Natural Selection

Question 1

What are the 6 stages of natural selection?

Answer 1

1) Mutation
2) Variation
3) Competitive advantage
4) Survival of the fittest
5) Reproduction
6) Pass advantageous alleles to offspring

Question 2

How does natural selection increase biodiversity?

Answer 2

As a habitat changes, individuals that are more adapted to the environment reproduce until lots of the population has these alleles. Then the environment changes again and the makeup of the population changes creating biodiversity.

Question 3

How does natural selection decrease biodiversity?

Answer 3

For example if a selective insecticide kills all the aphids in a habitat this would decreases biodiversity

Question 4

What is an adaptation?

Answer 4

The change in a species as a useful characteristic becomes more common and this characteristic is called an adaptive trait

Question 5

What are the environmental factors that effect an individuals reproductive success

Answer 5

Selection pressures

Question 6

What is an anatomical trait held by an animal that helps it live?

Answer 6

Sharks have streamlined bodies. Without this body shape they would be less efficient at catching food or escaping predators

Question 7

What is a physiological trait held by an animal to help it survive?

Answer 7

Animals do not want to waste energy to maintain body their temperature. Polar bears drop their body temperature to 2 Celsius rather than 37 Celsius during hibernation to use less energy.

Question 8

What is a behaviour trait of plant that helps it to survive?

Answer 8

Many plants like the hawthorn flower in spring when it’s pollinating insects have emerged, if it did not flower then it would not be pollinated

Question 9

Selective predation

Answer 9

Individuals less adapted get eaten