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.
Fig. 5.1 shows Mackinlay's cuckoo-dove, Macropygia mackinlayi, which is found on most of the islands in the south-west of the Pacific Ocean.
Fig. 5.1
Karkar Island is one island where Mackinlay's cuckoo-dove is found. This species is part of many communities that are adapted to the different habitats on the island.
Complete the passage with the most appropriate word or phrase.
Adaptation is sometimes defined as the process resulting from ______ by which populations become more suited to their ______ over many generations.
A scientist tested the resistance of one strain of bacteria to different antibiotics.
The scientist tested solutions of five different antibiotics, A to E.
She soaked a paper disc in each antibiotic solution.
The paper discs with antibiotics were placed in a Petri dish containing bacteria on agar jelly.
Fig. 4.2 is a diagram of the appearance of the Petri dish after 48 hours. The shaded areas show where bacteria grew. The clear areas show where bacteria did not grow.
Fig. 4.2
The results in Fig. 4.2 show that this strain of bacteria is resistant to antibiotic A.
Five years ago, a similar investigation found that the clear area for antibiotic A was the same size as antibiotic B is in Fig. 4.2.
Explain how bacteria become resistant to antibiotics.
Describe how artificial selection differs from natural selection.