Practise selection questions by sequencing natural selection, applying selective breeding steps and explaining antibiotic resistance or artificial-selection differences.
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
Anthocyanin is a red pigment found in carnation flowers. Some carnation plants have a gene for making anthocyanin.
A flower grower bred red carnations.
Describe how growers selectively breed plants.
Tasmania is an island off the south coast of Australia. Sheep were introduced to Tasmania in the nineteenth century.
Fig. 3.1 shows the population of sheep in Tasmania from 1820 to 1940. The dashed line shows the trend in the population growth.
The sheep that were first introduced to Tasmania were not well adapted to the environment.
Describe how farmers can use selective breeding to improve their sheep so that they are better adapted to the environment.