Natural selection

Question 1

What are selection pressures?

Answer 1

These are factors present in an organism’s environment that affect the chances of survival and reproduction.
Examples -> competition for food, the threat of predators , disease

Question 2

Process of natural selection.

Answer 2

• Organisms show genetic variation due to new alleles arising from time to time.
• Random mutations in the DNA base sequence cause genes to alter.
• It is the presence of different alleles that gives genetic variation within the population.
• When a particular selection pressure exerts itself on a population, those individuals that are best adapted are more likely to survive and breed. They will pass on their useful alleles to their offspring, so the offspring spring show similar characteristics to the parents.