Selection and evolution: past paper questions
Real questions on selection and evolution
The newest 20 of 110 written questions, plus 1 multiple-choice. Open one to see it on the real paper.
- 9700/41 · May/June 2025 · Q3b[3]
Variegate porphyria occurs in 1 in 100 000 people in Europe. In the 1600s, approximately 100 Dutch people migrated from Europe to South Africa. The population of people of Dutch descent in South Africa is now 2.5 million. Variegate porphyria occurs in 1 in 1000 people in this population. Suggest and explain why variega...
See it on the paper → - 9700/41 · May/June 2025 · Q5a(i)[1]
State the type of natural selection that occurred in the G. fortis population on Daphne Major as a result of the drought.
See it on the paper → - 9700/41 · May/June 2025 · Q5a(ii)[1]
Fig. 5.2 shows the distribution of bill size in the G. fortis population before the drought in 1977. number of G. fortis bill size Fig. 5.2 Sketch a new curve on Fig. 5.2 to show the distribution of bill size in the G. fortis (ii)
See it on the paper → - 9700/41 · May/June 2025 · Q5b[4]
G. fortis also lives on Santa Cruz, another island in the Galápagos. Most of the seeds available for G. fortis to eat on Santa Cruz are either small or large. There are few intermediate sizes of seed. Fig. 5.3 shows the distribution of bill size in the G. fortis population on Santa Cruz. number of G. fortis bill size F...
See it on the paper → - 9700/42 · May/June 2025 · Q3b[1]
It is common for wild rice plants to have grains with awns present. Suggest a selective advantage to wild rice of having awns present on their grains.
See it on the paper → - 9700/42 · February/March 2025 · Q2a(i)[1]
There are two distinct types of orca in the Northeast Atlantic Ocean: Type 1 and Type 2. Type 1 orca feed mainly on fish. Type 2 orca feed mainly on aquatic mammals, such as seals. Fig. 2.2 shows the locations in the Northeast Atlantic Ocean where Type 1 orca and Type 2 orca have been observed. Orca do not occur only i...
See it on the paper → - 9700/42 · February/March 2025 · Q2a(ii)[3]
Suggest examples of behavioural separation that would contribute to sympatric speciation of Type 1 orca and Type 2 orca.
See it on the paper → - 9700/42 · February/March 2025 · Q2b(i)[1]
With reference to Fig. 2.4, state one way in which the Type D orca is different from both the Type B orca and the Type C orca.
See it on the paper → - 9700/42 · February/March 2025 · Q2b(ii)[3]
Phenotypic differences between Type D orca and the other types of orca shown in Fig. 2.4 could have resulted from the process of genetic drift, including the founder effect. Suggest how genetic drift could result in phenotypic differences between Type D orca and the other types of orca shown in Fig. 2.4.
See it on the paper → - 9700/42 · February/March 2025 · Q2c[2]
In the future, the different types of orca may be classified as separate species. If so, some of these newly classified species will have very small population sizes. Suggest two factors, other than population size, that should be monitored when assessing the conservation status of any newly classified species of orca....
See it on the paper → - 9700/41 · October/November 2024 · Q7a(i)[3]
In pond 1, the scientists observed: • • • a high density of tadpoles a low abundance of food that most of the tadpoles they counted were either detritus feeders or carnivores, with very few intermediates present. Describe and suggest explanations for the type of natural selection that appears to be acting in pond 1.
See it on the paper → - 9700/41 · October/November 2024 · Q7a(ii)[3]
In pond 2, the scientists observed: • • • a low density of tadpoles sufficient food availability for all tadpoles that most of the tadpoles they counted were intermediates, with fewer detritus feeders or carnivores. Describe and suggest explanations for the type of natural selection that appears to be acting in pond 2.
See it on the paper → - 9700/41 · October/November 2024 · Q7a(iii)[1]
The intestine length of S. multiplicata tadpoles shows continuous variation. Sketch a curve on Fig. 7.2 to show how intestine length varies in the tadpole population in pond 2. length of intestine number of tadpoles
See it on the paper → - 9700/41 · October/November 2024 · Q7a(iv)[2]
A student suggested that the variation in S. multiplicata tadpoles could lead to sympatric speciation in some populations. Outline the features of sympatric speciation. (iv)
See it on the paper → - 9700/41 · October/November 2024 · Q7b[3]
Fig. 7.3 shows the evolutionary relationships between three species of American spadefoot toad. Spea multiplicata Spea hammondii Spea bombifrons 60 40 20 0 time / millions of years ago Fig. 7.3 Explain how analysis of DNA allowed the evolutionary relationships shown in Fig. 7.3 to be determined.
See it on the paper → - 9700/43 · October/November 2024 · Q7a(i)[3]
In pond 1, the scientists observed: • • • a high density of tadpoles a low abundance of food that most of the tadpoles they counted were either detritus feeders or carnivores, with very few intermediates present. Describe and suggest explanations for the type of natural selection that appears to be acting in pond 1.
See it on the paper → - 9700/43 · October/November 2024 · Q7a(ii)[3]
In pond 2, the scientists observed: • • • a low density of tadpoles sufficient food availability for all tadpoles that most of the tadpoles they counted were intermediates, with fewer detritus feeders or carnivores. Describe and suggest explanations for the type of natural selection that appears to be acting in pond 2.
See it on the paper → - 9700/43 · October/November 2024 · Q7a(iii)[1]
The intestine length of S. multiplicata tadpoles shows continuous variation. Sketch a curve on Fig. 7.2 to show how intestine length varies in the tadpole population in pond 2. length of intestine number of tadpoles
See it on the paper → - 9700/43 · October/November 2024 · Q7a(iv)[2]
A student suggested that the variation in S. multiplicata tadpoles could lead to sympatric speciation in some populations. Outline the features of sympatric speciation. (iv)
See it on the paper → - 9700/41 · May/June 2024 · Q9c[2]
The body size of adult H. axyridis varies from 5 mm to 8 mm. Adult ladybirds do not grow or change size. Adults develop from larvae that hatch from eggs. State two environmental factors that may affect adult body size in H. axyridis.
See it on the paper →
What examiners said
Most candidates were able to use the information in Fig. 2.2 to explain why this type of speciation is sympatric. Some referred to features of sympatric speciation that could not be deduced from the figure, such as behavioural isolation.
— Examiner report, February/March 2025, 9700/42 Q2(a)(i) (Cambridge)
Differences in diet and differences in mating behaviour were the two most frequent examples of behavioural separation suggested by candidates. Fewer candidates identified other examples, such as differences in social group sizes.
— Examiner report, February/March 2025, 9700/42 Q2(a)(ii) (Cambridge)
Nearly all candidates identified at least one difference between the Type B, Type C and Type D orca. The black colouration present along the back and dorsal fin of Type B and Type C orca, but absent from Type D orca, was the most commonly stated difference.
— Examiner report, February/March 2025, 9700/42 Q2(b)(i) (Cambridge)
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