Natural selection

Question 1

Explain how natural variation occurs

Answer 1

Mutation occurs
Providing advantageous variation
Organisms with mutation survives longer
Reproduces and allele passed on to offspring

Question 2

Explain anitbiotic resistance

Answer 2

A random mutation may occur in a bacterium that gives it resistance to an antibiotic.
When an antibiotic is used, it kills the non-resistant bacteria, but those with the mutation survive.
The resistant bacteria then reproduce, passing on the resistance gene to their offspring.
Over time, the population of resistant bacteria increases.
As more bacteria become resistant, infections become harder to treat with standard antibiotics.