Selection

Question 1

What is population?

Answer 1

A group of organisms at the same place at the same time.

Question 2

What is an allele?

Answer 2

A different version of the same gene.

Question 3

What is the model answer for natural selection (with polar bears)?

Answer 3

-Mutations lead to variation for example white and brown fur polar bears.
-The snow in the environment is also whit so the white fur polar bears will be able to survive and reproduce passing the white fur allele down to an offspring.
-Those with brown fur will die out.
-So the allele for white fur increases in frequency within the population of polar bears.

Question 4

What is artificial selection?

Answer 4

-Selection which is forced by humans.

Question 5

What is selection pressures?

Answer 5

An environmental force which can alter the frequency of alleles in a population.
-E.G: temperature, disease, predators.

Question 6

What is directional selection?

Answer 6

After an environmental change pressure is exerted on a specific portion of the population so optimum shifts.

Question 7

What is stabilising selection?

Answer 7

Both ends of the population are selected against.
-So no longer any advantageous alleles.

Question 8

What is disruptive selection?

Answer 8

-Middle/mean is selected against so leads to two separate species.