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Secondary 4 Combined Science Biology Evolution Diversity Quiz
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Secondary 4 Combined Science Biology Quiz - Evolution Diversity
Name: _________________________ Class: _________________________ Date: _________________________ Score: ______ / 40
Duration: 45 minutes Total Marks: 40
Instructions:
- This quiz contains 20 questions on Evolution and Diversity.
- Answer ALL questions in the spaces provided.
- The number of marks for each question is shown in brackets.
- Read each question carefully before answering.
- Where calculations are required, show your working clearly.
Section A: Short Answer (10 marks) Answer all questions in this section.
1. State what is meant by the term "natural selection." [2 marks]
2. Define the term "species" as used in biological classification. [1 mark]
3. State one piece of evidence from comparative anatomy that supports the theory of evolution. [1 mark]
4. Explain why antibiotic resistance in bacteria is considered an example of evolution by natural selection. [3 marks]
5. State the binomial (scientific) name for modern humans. [1 mark]
Section B: Structured Questions (10 marks) Answer all questions in this section.
6. Distinguish between continuous variation and discontinuous variation. Give one example of each. [2 marks]
7. The diagram below shows the forelimb bones of four different vertebrates: a human, a whale, a bat, and a bird.
(a) Name the structure formed by these similar bone arrangements in different species. [1 mark]
(b) Explain how these structures provide evidence for evolution from a common ancestor. [2 marks]
(c) Suggest why the forelimbs of these vertebrates have different external appearances despite having similar bone structures. [2 marks]
8. The peppered moth (Biston betularia) exists in two forms: a light-coloured (typical) form and a dark-coloured (melanic) form. Before the Industrial Revolution in England, the light form was more common. During the Industrial Revolution, tree trunks became darkened by soot, and the dark form became more common.
(a) Explain why the dark form of the peppered moth became more common during the Industrial Revolution. [3 marks]
(b) After clean air legislation was introduced, the light form became more common again. Explain this observation. [2 marks]
9. The graph below shows the distribution of two species of fish, Species X and Species Y, along a river system. Species X is found in the upper reaches (cooler water), while Species Y is found in the lower reaches (warmer water). A third species, Species Z, is found in a separate lake connected to the river.
(a) Suggest how Species X and Species Y may have evolved from a common ancestral population. [3 marks]
(b) Explain why Species Z in the lake may have evolved different characteristics from Species X and Species Y in the river. [2 marks]
10. The table below shows the percentage similarity of DNA sequences between humans and four other primate species.
| Primate Species | DNA Similarity to Humans (%) |
|---|---|
| Chimpanzee | 98.8 |
| Gorilla | 98.4 |
| Orangutan | 96.9 |
| Gibbon | 94.7 |
(a) Using the data, state which primate is most closely related to humans. Explain your answer. [1 mark]
(b) Explain how DNA sequencing provides evidence for evolutionary relationships between species. [2 marks]
Section C: Data-Based Questions (10 marks) Answer all questions in this section.
11. A scientist studied a population of snails on a small island. The snails showed variation in shell colour: some had light shells and others had dark shells. The island had both light-coloured rocks and dark-coloured soil patches. Birds were the main predators of the snails.
The scientist recorded the number of light and dark snails eaten by birds on different backgrounds over one month. The results are shown below.
| Background Colour | Light Snails Eaten | Dark Snails Eaten |
|---|---|---|
| Light rocks | 12 | 48 |
| Dark soil | 52 | 8 |
(a) Describe the pattern shown by the data. [2 marks]
(b) Explain how natural selection could lead to the evolution of different shell colours in snail populations living on different backgrounds. [4 marks]
(c) Suggest why both light and dark snails continue to exist on the island, rather than only one form. [2 marks]
12. The theory of evolution by natural selection was proposed by Charles Darwin and Alfred Russel Wallace. Despite strong evidence supporting the theory, some people do not accept it.
(a) Describe how the development of antibiotic resistance in bacteria supports the theory of evolution by natural selection. [3 marks]
(b) Suggest one reason why some people may not accept the theory of evolution. [1 mark]
13. The diagram below shows the evolutionary relationships among four species of flightless birds: the ostrich (Africa), rhea (South America), emu (Australia), and kiwi (New Zealand). These birds are found on different continents separated by oceans.
Explain how the theory of evolution accounts for the distribution of these flightless birds on different continents. [2 marks]
14. A population of insects is exposed to a new pesticide. Initially, the pesticide kills almost all the insects. After several years of repeated pesticide use, the pesticide becomes much less effective.
Explain how the insect population evolved resistance to the pesticide. [3 marks]
15. The table below shows the number of differences in the amino acid sequence of cytochrome c, a protein found in all aerobic organisms, between humans and five other organisms.
| Organism | Number of Amino Acid Differences in Cytochrome c (compared to humans) |
|---|---|
| Chimpanzee | 0 |
| Rhesus monkey | 1 |
| Dog | 11 |
| Tuna fish | 21 |
| Yeast | 44 |
(a) State the relationship between the number of amino acid differences and the time since two species shared a common ancestor. [1 mark]
(b) Explain how molecular evidence, such as cytochrome c comparisons, supports the theory of evolution. [2 marks]
Section D: Extended Response (10 marks) Answer all questions in this section.
16. Discuss how the fossil record provides evidence for evolution. In your answer, you should include reference to the formation of fossils and what the fossil record shows about changes in organisms over time. [4 marks]
17. Explain how geographical isolation can lead to the formation of a new species. Use a named example to support your answer. [4 marks]
18. A farmer uses a herbicide to control weeds in a crop field. After several years, the herbicide becomes less effective at killing the weeds.
Explain how the weed population has evolved resistance to the herbicide. [3 marks]
19. Compare the processes of artificial selection and natural selection. Give one example of each. [4 marks]
20. Discuss the importance of genetic variation within a population for the survival of a species in a changing environment. Use a specific example to support your answer. [3 marks]
END OF QUIZ
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Answers
Secondary 4 Combined Science Biology Quiz - Evolution Diversity
ANSWER KEY AND MARKING SCHEME
Total Marks: 40
Section A: Short Answer (10 marks)
1. State what is meant by the term "natural selection." Answer: Natural selection is the process by which organisms with characteristics better adapted to their environment are more likely to survive and reproduce, passing on these favourable characteristics to their offspring. [2 marks]
- Award 1 mark for: organisms with favourable/better-adapted characteristics survive.
- Award 1 mark for: these organisms reproduce and pass on characteristics to offspring.
2. Define the term "species" as used in biological classification. Answer: A species is a group of organisms that can interbreed to produce fertile offspring. [1 mark]
- Accept: organisms that share similar characteristics and can reproduce naturally to produce fertile offspring.
3. State one piece of evidence from comparative anatomy that supports the theory of evolution. Answer: Any one of the following [1 mark]:
- Pentadactyl limb (five-fingered limb structure) in different vertebrates.
- Homologous structures (similar bone arrangements) in forelimbs of mammals, birds, reptiles.
- Vestigial organs (e.g., appendix in humans, pelvic bones in whales).
4. Explain why antibiotic resistance in bacteria is considered an example of evolution by natural selection. Answer: [3 marks]
- Within a bacterial population, there is genetic variation; some bacteria possess genes for antibiotic resistance due to random mutations (1 mark).
- When antibiotics are used, non-resistant bacteria are killed, while resistant bacteria survive (1 mark).
- The resistant bacteria reproduce and pass on the resistance genes to their offspring, increasing the proportion of resistant bacteria in the population over generations (1 mark).
5. State the binomial (scientific) name for modern humans. Answer: Homo sapiens [1 mark]
- Must be correctly formatted: genus name capitalised, species name lowercase, both italicised or underlined.
Section B: Structured Questions (10 marks)
6. Distinguish between continuous variation and discontinuous variation. Give one example of each. Answer: [2 marks]
- Continuous variation: characteristics that show a range of phenotypes with no distinct categories (e.g., height, body mass, skin colour). (1 mark for correct distinction and example)
- Discontinuous variation: characteristics that fall into distinct categories with no intermediates (e.g., blood groups, tongue rolling ability, eye colour). (1 mark for correct distinction and example)
- Award 1 mark for each correct distinction with example.
7. Forelimb bones of vertebrates.
(a) Name the structure formed by these similar bone arrangements in different species. Answer: Pentadactyl limb / homologous structures [1 mark]
(b) Explain how these structures provide evidence for evolution from a common ancestor. Answer: [2 marks]
- The similar bone arrangement (basic structural plan) in different vertebrates suggests they inherited this structure from a common ancestor (1 mark).
- The differences in shape and function are due to adaptation to different environments/modes of life (divergent evolution), while the underlying similarity indicates shared ancestry (1 mark).
(c) Suggest why the forelimbs of these vertebrates have different external appearances despite having similar bone structures. Answer: [2 marks]
- Each species has adapted to a different environment or way of life (1 mark).
- Natural selection has favoured different modifications of the basic limb structure for different functions (e.g., flying in bats, swimming in whales, grasping in humans) (1 mark).
8. Peppered moth.
(a) Explain why the dark form of the peppered moth became more common during the Industrial Revolution. Answer: [3 marks]
- Before the Industrial Revolution, tree trunks were light-coloured; light moths were camouflaged and less likely to be eaten by birds (1 mark).
- During the Industrial Revolution, soot darkened tree trunks; dark moths became better camouflaged on darkened trees (1 mark).
- Dark moths survived and reproduced more than light moths, passing on the dark colour gene to offspring; over generations, the dark form became more common (1 mark).
(b) After clean air legislation was introduced, the light form became more common again. Explain this observation. Answer: [2 marks]
- Clean air legislation reduced soot pollution; tree trunks became lighter again (1 mark).
- Light moths became better camouflaged once more, survived and reproduced more successfully; the light form increased in frequency (1 mark).
9. Fish species distribution.
(a) Suggest how Species X and Species Y may have evolved from a common ancestral population. Answer: [3 marks]
- The ancestral population may have become separated into two groups (geographical isolation), one in the upper reaches and one in the lower reaches of the river (1 mark).
- Each group experienced different environmental conditions (e.g., different water temperatures, food sources, predators) and therefore different selection pressures (1 mark).
- Over many generations, natural selection favoured different characteristics in each group; eventually, they became so different that they could no longer interbreed, forming two separate species (1 mark).
(b) Explain why Species Z in the lake may have evolved different characteristics from Species X and Species Y in the river. Answer: [2 marks]
- Species Z is geographically isolated from the river populations; there is no gene flow between the lake and river populations (1 mark).
- The lake environment has different selection pressures (e.g., different predators, food availability, water conditions); natural selection favours different adaptations in the lake population, leading to divergence (1 mark).
10. DNA similarity data.
(a) Using the data, state which primate is most closely related to humans. Explain your answer. Answer: Chimpanzee [1 mark]
- Chimpanzees have the highest percentage DNA similarity to humans (98.8%), indicating the most recent common ancestor / closest evolutionary relationship.
(b) Explain how DNA sequencing provides evidence for evolutionary relationships between species. Answer: [2 marks]
- DNA sequencing allows comparison of the base sequences in the DNA of different species (1 mark).
- Species that share a more recent common ancestor have more similar DNA sequences (fewer differences/mutations accumulated); the greater the similarity, the closer the evolutionary relationship (1 mark).
Section C: Data-Based Questions (10 marks)
11. Snail shell colour study.
(a) Describe the pattern shown by the data. Answer: [2 marks]
- On light rocks, more dark snails (48) were eaten than light snails (12) (1 mark).
- On dark soil, more light snails (52) were eaten than dark snails (8) (1 mark).
- Accept: Snails with shell colour matching the background were eaten less; snails with contrasting shell colour were eaten more.
(b) Explain how natural selection could lead to the evolution of different shell colours in snail populations living on different backgrounds. Answer: [4 marks]
- There is variation in shell colour within the snail population (light and dark shells) due to genetic differences (1 mark).
- On light rocks, light-shelled snails are better camouflaged; they are less likely to be seen and eaten by birds, so they survive and reproduce more than dark snails (1 mark).
- On dark soil, dark-shelled snails are better camouflaged; they survive and reproduce more than light snails (1 mark).
- Over many generations, the frequency of the advantageous shell colour allele increases in each population; the population on light rocks evolves to be predominantly light-shelled, while the population on dark soil evolves to be predominantly dark-shelled (1 mark).
(c) Suggest why both light and dark snails continue to exist on the island, rather than only one form. Answer: [2 marks]
- The island has a variety of backgrounds (light rocks and dark soil patches), providing different selective pressures in different microhabitats (1 mark).
- Snails may move between backgrounds, or both colour forms may have some advantage in different areas; this maintains both alleles in the population (balanced polymorphism) (1 mark).
12. Theory of evolution.
(a) Describe how the development of antibiotic resistance in bacteria supports the theory of evolution by natural selection. Answer: [3 marks]
- Within a bacterial population, there is genetic variation; some bacteria possess genes for antibiotic resistance due to random mutations (1 mark).
- When antibiotics are used, non-resistant bacteria are killed, while resistant bacteria survive (1 mark).
- The resistant bacteria reproduce and pass on the resistance genes to their offspring, increasing the proportion of resistant bacteria in the population over generations (1 mark).
(b) Suggest one reason why some people may not accept the theory of evolution. Answer: [1 mark]
- Any one of the following:
- Religious beliefs that conflict with evolutionary theory (e.g., belief in creationism).
- Lack of understanding of the scientific evidence.
- Belief that evolution cannot explain the complexity of life.
- Preference for alternative explanations.
13. Flightless birds distribution. Answer: [2 marks]
- The distribution of flightless birds on different continents suggests they evolved from a common ancestor that lived when the continents were joined together (Gondwana) (1 mark).
- After the continents separated (continental drift), populations became geographically isolated and evolved independently into different species on each continent (1 mark).
14. Insect pesticide resistance. Answer: [3 marks]
- Within the insect population, there was genetic variation; some insects possessed genes for pesticide resistance due to random mutations (1 mark).
- When the pesticide was applied, susceptible insects were killed, while resistant insects survived (1 mark).
- The resistant insects reproduced and passed on the resistance genes to their offspring; over generations, the proportion of resistant insects increased, making the pesticide less effective (1 mark).
15. Cytochrome c data.
(a) State the relationship between the number of amino acid differences and the time since two species shared a common ancestor. Answer: The greater the number of amino acid differences, the longer the time since the two species shared a common ancestor. [1 mark]
(b) Explain how molecular evidence, such as cytochrome c comparisons, supports the theory of evolution. Answer: [2 marks]
- All aerobic organisms share the same basic protein (cytochrome c), indicating a common ancestry (1 mark).
- The number of differences in the amino acid sequence reflects the degree of evolutionary divergence; species that diverged more recently have fewer differences, supporting the branching pattern of evolution (1 mark).
Section D: Extended Response (10 marks)
16. Discuss how the fossil record provides evidence for evolution. Answer: [4 marks]
- Fossils are the preserved remains or traces of organisms that lived in the past; they form when organisms are buried quickly in sediments and hard parts are replaced by minerals (1 mark).
- The fossil record shows that organisms have changed over time; simpler organisms are found in older rocks, while more complex organisms appear in younger rocks (1 mark).
- Fossils show transitional forms (e.g., Archaeopteryx between reptiles and birds) that link different groups of organisms (1 mark).
- The sequence of fossils supports the idea that life has evolved gradually over millions of years, with new species arising from pre-existing ones (1 mark).
17. Explain how geographical isolation can lead to the formation of a new species. Use a named example to support your answer. Answer: [4 marks]
- Geographical isolation occurs when a population is divided by a physical barrier (e.g., a mountain range, river, or ocean), preventing gene flow between the separated groups (1 mark).
- The separated populations experience different environmental conditions and selection pressures (1 mark).
- Over many generations, natural selection and random mutations lead to the accumulation of different genetic changes in each population (1 mark).
- Eventually, the populations become so genetically different that they can no longer interbreed to produce fertile offspring, forming new species. Example: Darwin's finches on the Galapagos Islands, where different beak shapes evolved on different islands due to different food sources (1 mark).
18. Herbicide resistance in weeds. Answer: [3 marks]
- Within the weed population, there was genetic variation; some weeds possessed genes for herbicide resistance due to random mutations (1 mark).
- When the herbicide was applied, susceptible weeds were killed, while resistant weeds survived (1 mark).
- The resistant weeds reproduced and passed on the resistance genes to their offspring; over generations, the proportion of resistant weeds increased, making the herbicide less effective (1 mark).
19. Compare the processes of artificial selection and natural selection. Give one example of each. Answer: [4 marks]
- Artificial selection: humans select organisms with desirable traits to breed; selection is based on human needs/wants. Example: breeding of different dog breeds from wolves, or selective breeding of crops for higher yield (2 marks).
- Natural selection: the environment selects organisms with traits that enhance survival and reproduction; selection is based on environmental pressures. Example: antibiotic resistance in bacteria, or camouflage in peppered moths (2 marks).
- Award 1 mark for each correct description and 1 mark for each correct example.
20. Discuss the importance of genetic variation within a population for the survival of a species in a changing environment. Use a specific example to support your answer. Answer: [3 marks]
- Genetic variation provides the raw material for natural selection; without variation, a population cannot adapt to changing conditions (1 mark).
- In a changing environment, individuals with advantageous traits are more likely to survive and reproduce, ensuring the survival of the species (1 mark).
- Example: In the peppered moth, genetic variation in colour allowed the population to adapt to changes in tree trunk colour during and after the Industrial Revolution; if all moths were the same colour, the population might have been wiped out when the environment changed (1 mark).
END OF ANSWER KEY