Natural Selection

Question 1

Steps of natural selection

Answer 1

1. Variation (of phenotype) must exist within a species
2. The environment, possible a changing environment must favour the survival, to reproductive age of certain phenotype over others.
3. The phenotype must be inheritable, it must be due to genetic control
4. Over generations the reproduction and survival rate of those individuals with the favoured genotype so will be greater
5. After generations frequency of the allele for the favourable characteristic, in the gene pool will increase

Question 2

What is natural selection

Answer 2

The process where an environmental factor acts on a population and results in some organisms having more off springs than others

Question 3

Selective agent

Answer 3

The environmental factor that acts on a population and results in some organisms having more offsprings than others.

Question 4

Selective pressures

Answer 4

The effect of natural selection on the population is referred to as the selective pressure

Question 5

Factors that cause individuals not to survive to reproductive age (4)

Answer 5

1. Competition for food
2. Predators
3. Inability to find a mate
4. Inability to survive disease

Question 6

Artificial selection

Answer 6

The process in which people chose what individuals will be bred with the desirable characteristics

Question 7

4 pieces of evidence that evolution has occurred

Answer 7

1. Fossils
2. Comparative anatomy: comparing the structure of living organisms with fossils
3. DNA
4. Embryology: Embryos show similarities and differences in early stages of development