Practise describing how genetic variation, many offspring and competition create a struggle for survival, so better-adapted individuals have a greater chance to reproduce and pass on their alleles.
The photograph shows a species of fish called a leafy sea-dragon.
Leafy sea-dragons live in areas of the sea where seaweed is present.
Which statements explain how natural selection caused the leafy sea-dragon species to develop?
1 Leafy sea-dragons that looked like seaweed were better adapted to their environment.
2 Leafy sea-dragons that survived passed on the allele for their appearance to their offspring.
3 Humans selected leafy sea-dragons that looked like seaweed.
1, 2 and 3
1 and 2 only
1 and 3 only
2 and 3 only