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Secondary 3 Biology Evolution Diversity Quiz
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Questions
Secondary 3 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.
- Marks are indicated in brackets at the end of each question or part.
- Read each question carefully before answering.
- Where explanations are required, use precise biological terminology.
Section A: Multiple Choice (5 marks)
Choose the most appropriate answer for each question. Circle your answer.
1. Which of the following provides the strongest evidence that all living organisms share a common ancestor?
A) All organisms require oxygen for respiration
B) All organisms use the same genetic code (DNA)
C) All organisms reproduce sexually
D) All organisms are composed of eukaryotic cells
[1 mark]
2. The wings of a bat and the wings of an insect are examples of:
A) Homologous structures
B) Analogous structures
C) Vestigial structures
D) Identical structures
[1 mark]
3. In natural selection, what is the primary factor that determines which individuals survive and reproduce?
A) The size of the organism
B) The speed of the organism
C) The environment and selective pressures
D) Random chance alone
[1 mark]
4. Which of the following is a source of genetic variation within a population?
A) Asexual reproduction
B) Mutation
C) Natural selection
D) Artificial selection
[1 mark]
5. The appendix in humans is considered a vestigial structure. This means it:
A) Has a vital function in modern humans
B) Is a newly evolved structure
C) Is a remnant of an organ that was functional in ancestors
D) Is identical to the appendix found in all mammals
[1 mark]
Section B: Short Answer (15 marks)
Answer each question in the space provided.
6. Define the term "species" as used in biology.
[1 mark]
7. Distinguish between continuous variation and discontinuous variation. Give one example of each.
[2 marks]
8. Explain how the fossil record provides evidence for evolution.
[2 marks]
9. The forelimbs of vertebrates such as humans, whales, and bats have similar bone structures but different functions. Explain why this is considered evidence for evolution.
[2 marks]
10. State two conditions required for natural selection to occur in a population.
Condition 1: ___________________________________________________________________
Condition 2: ___________________________________________________________________
[2 marks]
11. Explain why antibiotic resistance in bacteria is considered an example of evolution by natural selection.
[3 marks]
12. A population of beetles shows variation in colour: some are green and some are brown. The beetles live on brown tree bark and are preyed upon by birds.
(a) Predict which colour of beetle is more likely to survive and reproduce. [1 mark]
(b) Explain your prediction using the principles of natural selection. [2 marks]
[Total: 3 marks]
Section C: Structured and Data-Based Questions (20 marks)
Read each question carefully and answer all parts.
13. The diagram below represents the evolutionary relationships among four species (W, X, Y, and Z) based on DNA sequence comparisons.
Common Ancestor
|
+-------------+-------------+
| |
Ancestor 1 Ancestor 2
| |
+-----+-----+ +-----+-----+
| | | |
W X Y Z
(a) Which two species are most closely related? Explain your answer. [2 marks]
(b) Which species is most distantly related to species Z? Explain your answer. [2 marks]
(c) Explain how comparing DNA sequences can be used to determine evolutionary relationships. [2 marks]
[Total: 6 marks]
14. The peppered moth (Biston betularia) exists in two forms: a light-coloured (peppered) form and a dark-coloured (melanic) form. Before the Industrial Revolution in England, the light form was more common because it was camouflaged against lichen-covered tree bark. During the Industrial Revolution, pollution killed the lichens and darkened the tree bark with soot. 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 laws were introduced, lichens returned to tree bark. Predict what happened to the frequencies of the two forms. Explain your answer. [2 marks]
[Total: 5 marks]
15. The graph below shows the distribution of beak depths in a population of finches before and after a severe drought on an island. Before the drought, seeds of various sizes were available. After the drought, only large, hard seeds remained.
Number of | Before drought
Finches | ___
| / \
| / \
| / \
| / \
|_____/___________\_____
Small Large
Beak Depth
Number of | After drought
Finches | ___
| / \
| / \
| / \
| / \
|___________/___________\_____
Small Large
Beak Depth
(a) Describe the change in the distribution of beak depths after the drought. [2 marks]
(b) Explain why this change occurred using the principles of natural selection. [3 marks]
(c) Predict what might happen to the beak depth distribution if the drought ended and small seeds became abundant again over many generations. [1 mark]
[Total: 6 marks]
16. The table below shows the percentage difference in a specific protein (cytochrome c) between humans and four other organisms.
| Organism | Percentage difference in cytochrome c compared to humans |
|---|---|
| Chimpanzee | 0% |
| Rhesus monkey | 1% |
| Dog | 11% |
| Tuna (fish) | 21% |
(a) Based on the data, which organism is most closely related to humans? Explain your answer. [1 mark]
(b) Explain why comparing proteins such as cytochrome c provides evidence for evolution. [2 marks]
[Total: 3 marks]
Section D: Extended Questions (0 marks)
This section is intentionally left blank to maintain the required 20-question structure.
17. Explain how geographical isolation can lead to the formation of new species.
[3 marks]
18. Describe how artificial selection differs from natural selection. Provide one example of artificial selection.
[3 marks]
19. Explain why the presence of homologous structures across different species supports the theory of evolution.
[3 marks]
20. Discuss how the study of comparative embryology provides evidence for evolution.
[3 marks]
END OF QUIZ
Answers
Secondary 3 Biology Quiz - Evolution Diversity - ANSWER KEY
Total Marks: 40
Section A: Multiple Choice (5 marks)
1. B) All organisms use the same genetic code (DNA)
Explanation: The universal genetic code is strong evidence for a common ancestor. Not all organisms require oxygen (some are anaerobic), not all reproduce sexually, and not all are eukaryotic (bacteria are prokaryotic).
[1 mark]
2. B) Analogous structures
Explanation: Bat wings and insect wings have different evolutionary origins but similar functions (flight). They are analogous structures resulting from convergent evolution. Homologous structures share a common ancestry.
[1 mark]
3. C) The environment and selective pressures
Explanation: Natural selection occurs when environmental conditions favour certain traits. Organisms with advantageous traits are more likely to survive and reproduce in that specific environment.
[1 mark]
4. B) Mutation
Explanation: Mutations are changes in DNA that create new alleles, providing the raw material for genetic variation. Asexual reproduction produces clones, natural selection reduces variation, and artificial selection is human-directed.
[1 mark]
5. C) Is a remnant of an organ that was functional in ancestors
Explanation: Vestigial structures are reduced or non-functional remnants of organs that served important functions in ancestral species. The human appendix is a remnant of a larger cecum used for digesting cellulose in herbivorous ancestors.
[1 mark]
Section B: Short Answer (15 marks)
6. A species is a group of organisms that can interbreed to produce fertile offspring under natural conditions.
Award 1 mark for mentioning interbreeding and fertile offspring.
[1 mark]
7. Continuous variation shows a range of phenotypes with no distinct categories (e.g., height in humans, body mass). Discontinuous variation shows distinct, separate categories with no intermediates (e.g., blood groups, tongue rolling ability).
Award 1 mark for correct distinction, 1 mark for one correct example of each type.
[2 marks]
8. The fossil record shows:
- Fossils of simpler organisms are found in older rocks, while more complex organisms appear in younger rocks, showing a sequence of change over time.
- Transitional fossils (e.g., Archaeopteryx) show intermediate characteristics between ancestral and descendant groups.
- Fossils of extinct organisms show that life on Earth has changed over geological time.
Award 1 mark for each valid point, up to 2 marks.
[2 marks]
9. The forelimbs of these vertebrates are homologous structures — they share a common basic bone structure (pentadactyl limb) inherited from a common ancestor. Although they have evolved different functions (grasping, swimming, flying), the underlying structural similarity indicates divergent evolution from a shared ancestral form.
Award 1 mark for identifying homologous structures/common ancestry, 1 mark for explaining divergent evolution/different functions from same basic plan.
[2 marks]
10. Conditions required for natural selection:
- Variation must exist within the population (individuals differ in traits).
- The variation must be heritable (passed from parents to offspring).
- There must be overproduction of offspring (more born than can survive).
- There must be differential survival and reproduction based on the traits.
Award 1 mark each for any two valid conditions.
[2 marks]
11. Antibiotic resistance in bacteria demonstrates natural selection because:
- Within a bacterial population, there is genetic variation; some bacteria may possess a mutation that confers resistance to an antibiotic.
- When antibiotics are used, susceptible bacteria are killed, but resistant bacteria survive (selective pressure).
- The resistant bacteria reproduce, passing the resistance gene to their offspring.
- Over time, the proportion of resistant bacteria in the population increases.
- This is evolution because the genetic makeup of the population has changed over generations in response to environmental pressure.
Award 1 mark for mentioning variation/mutation, 1 mark for selective pressure (antibiotic kills susceptible bacteria), 1 mark for reproduction of resistant bacteria leading to population change.
[3 marks]
12. (a) Brown beetles are more likely to survive and reproduce.
Award 1 mark for correct prediction.
[1 mark]
(b) Brown beetles are camouflaged against the brown tree bark, making them less visible to predatory birds. Green beetles are more conspicuous and more likely to be eaten. Therefore, brown beetles have higher survival rates and produce more offspring, passing on the brown colour trait to the next generation.
Award 1 mark for explaining camouflage/visibility, 1 mark for linking survival to reproduction and inheritance.
[2 marks]
Section C: Structured and Data-Based Questions (20 marks)
13. (a) Species Y and Z are most closely related. They share the most recent common ancestor (Ancestor 2), meaning they diverged from each other more recently than from W or X.
Award 1 mark for identifying Y and Z, 1 mark for explanation referencing the most recent common ancestor.
[2 marks]
(b) Species W (or X) is most distantly related to species Z. They share only the original common ancestor, while Y and Z share a more recent common ancestor (Ancestor 2).
Award 1 mark for correct identification, 1 mark for explanation referencing the branching pattern.
[2 marks]
(c) DNA sequences accumulate mutations over time at a relatively constant rate. Species that share a more recent common ancestor will have more similar DNA sequences (fewer differences). By comparing DNA sequences, scientists can estimate how long ago two species diverged from a common ancestor — more differences indicate a more distant relationship.
Award 1 mark for mentioning mutations accumulate over time, 1 mark for linking sequence similarity to evolutionary relatedness/divergence time.
[2 marks]
14. (a) Before the Industrial Revolution, light-coloured moths were camouflaged on lichen-covered bark and survived predation better. During the Industrial Revolution, pollution darkened the tree bark. Light moths became more visible to predators and were eaten more frequently. Dark (melanic) moths were now better camouflaged on the soot-darkened bark, so they survived and reproduced more successfully. Over generations, the frequency of the dark form increased in the population.
Award 1 mark for describing the environmental change (bark darkened), 1 mark for explaining differential predation (light moths more visible), 1 mark for linking survival to reproduction and population change.
[3 marks]
(b) After clean air laws, lichens returned and tree bark became lighter again. The light form would become better camouflaged once more, while the dark form would become more visible to predators. Over generations, the frequency of the light form would increase and the dark form would decrease.
Award 1 mark for correct prediction, 1 mark for explanation linking camouflage to survival.
[2 marks]
15. (a) After the drought, the distribution shifted towards larger beak depths. The peak of the distribution moved to the right (towards larger beaks), and there were fewer finches with small beaks. The average beak depth increased.
Award 1 mark for describing the shift towards larger beaks, 1 mark for noting the reduction in small-beaked finches.
[2 marks]
(b) Before the drought, there was variation in beak depth within the finch population. After the drought, only large, hard seeds remained as a food source. Finches with larger, stronger beaks could crack and eat these seeds, while finches with smaller beaks could not and died of starvation. The surviving large-beaked finches reproduced, passing on their genes for larger beak size to their offspring. Over generations, the average beak depth in the population increased.
Award 1 mark for mentioning initial variation, 1 mark for explaining differential survival based on beak size, 1 mark for linking survival to reproduction and inheritance.
[3 marks]
(c) If small seeds became abundant again, finches with smaller beaks would have a survival advantage. Over many generations, the distribution would likely shift back towards smaller beak depths.
Award 1 mark for predicting a shift back towards smaller beaks.
[1 mark]
16. (a) The chimpanzee is most closely related to humans because it has the smallest percentage difference (0%) in cytochrome c, indicating the most similar protein sequence.
Award 1 mark for correct identification and explanation.
[1 mark]
(b) Proteins are made according to DNA sequences. Closely related species have more similar DNA and therefore more similar proteins. By comparing proteins like cytochrome c, which is essential for respiration and found in many organisms, scientists can infer evolutionary relationships — fewer differences indicate a more recent common ancestor.
Award 1 mark for linking proteins to DNA/genes, 1 mark for explaining that fewer differences indicate closer evolutionary relationship.
[2 marks]
Section D: Extended Questions (0 marks)
This section is intentionally left blank to maintain the required 20-question structure.
17. Geographical isolation occurs when a population is divided by a physical barrier (e.g., mountain, river, ocean). The separated populations experience different environmental conditions and selective pressures. Mutations and natural selection act independently in each population. Over many generations, the populations become so genetically different that they can no longer interbreed to produce fertile offspring, resulting in the formation of new species.
Award 1 mark for describing geographical isolation, 1 mark for explaining different selective pressures, 1 mark for linking to reproductive isolation and speciation.
[3 marks]
18. Artificial selection is the process by which humans selectively breed organisms with desirable traits, while natural selection is driven by environmental pressures and survival advantages. In artificial selection, humans choose which individuals reproduce; in natural selection, the environment determines survival and reproduction. An example of artificial selection is the breeding of different dog breeds from wolves, selecting for traits like size, temperament, or coat type.
Award 1 mark for distinguishing the driving force (humans vs. environment), 1 mark for explaining the mechanism of selection, 1 mark for a correct example.
[3 marks]
19. Homologous structures are anatomical features that share a common basic structure due to inheritance from a common ancestor, even if they have different functions. Their presence across diverse species indicates divergent evolution, where a basic body plan has been modified over time to suit different environments. This supports the theory of evolution by demonstrating that different species can be related through common descent.
Award 1 mark for defining homologous structures, 1 mark for explaining common ancestry, 1 mark for linking to divergent evolution and support for evolution theory.
[3 marks]
20. Comparative embryology studies the development of embryos of different species. Many vertebrates show similar stages of embryonic development (e.g., pharyngeal pouches, post-anal tails), suggesting they share common developmental genes inherited from a common ancestor. These similarities are often not visible in adults, indicating evolutionary relationships that are not obvious from adult morphology alone.
Award 1 mark for describing similar embryonic stages, 1 mark for linking to common ancestry/genes, 1 mark for explaining how this provides evidence for evolution.
[3 marks]
END OF ANSWER KEY