7.2: Natural Selection

Question 1

What is a phenotype?

Answer 1

The organism’s physical characteristics

Question 2

What does natural selection act on (phenotype or genotype)?

Answer 2

Phenotypes

Question 3

What does natural selection modify (phenotype or genotype)?

Answer 3

Genotypes

Question 4

How does natural selection act on and modify different levels of genes?

Answer 4

An phenotype that is best suited to the environment will be selected for, and the genes of subsequent populations will be modified to reflect the advantageous phenotype.

Question 5

What are selective pressures?

Answer 5

Abiotic or biotic factor that is able to influence survival of an organism (disease, climate, food avial, ect)

Question 6

How does an environment apply a selective pressure to a population?

Answer 6

It determines which adaptations are affordable depending on the environmental conditions.

Question 7

Identify one examples of a phenotypic variation that increases fitness of an organism in a particular
environment.

Answer 7

Dark colored flies were able to better blend in with trees that were covered in soot, so they had increased fitness as they were able to reproduce more.