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Secondary 4 Pure Biology Evolution Diversity Quiz

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Questions

Secondary 4 Pure Biology Quiz - Evolution Diversity

Name: __________________________
Class: __________________________
Date: __________________________
Score: _________ / 40

Duration: 45 minutes
Total Marks: 40

Instructions:

Answer all questions.
Write your answers in the spaces provided.
The number of marks for each question or part question is given in brackets [ ].
You may use a calculator.

Section A: Multiple Choice Questions (Questions 1–5)

Choose the correct answer and write the letter in the box provided.

1. Which of the following best describes the process of natural selection?
A. Organisms change their characteristics during their lifetime to suit the environment.
B. Individuals with advantageous traits are more likely to survive and reproduce.
C. All individuals in a population evolve at the same rate.
D. Environmental changes cause mutations to occur in organisms.

Answer: [ ] [1]

2. The diagram below shows the forelimbs of a human, a bat, and a whale.
(Diagram description: Three skeletal structures showing similar bone arrangements—humerus, radius, ulna, carpals, metacarpals, phalanges—but different shapes and sizes suited for grasping, flying, and swimming.)

What evolutionary concept do these structures illustrate?
A. Convergent evolution
B. Adaptive radiation
C. Homologous structures
D. Analogous structures

Answer: [ ] [1]

3. Antibiotic resistance in bacteria is an example of evolution by natural selection. Which sequence correctly describes this process?

Resistant bacteria survive and reproduce.
A mutation occurs in some bacteria, making them resistant.
Antibiotics are applied, killing non-resistant bacteria.
The population of resistant bacteria increases.

A. 2 → 3 → 1 → 4
B. 1 → 2 → 3 → 4
C. 3 → 2 → 1 → 4
D. 2 → 1 → 3 → 4

Answer: [ ] [1]

4. Scientists compare the amino acid sequences of hemoglobin in different species. Species A and Species B have 98% identical sequences, while Species A and Species C have 85% identical sequences. What can be concluded?
A. Species A and C are more closely related than A and B.
B. Species A and B share a more recent common ancestor than A and C.
C. Species B and C cannot interbreed.
D. Species C evolved from Species B.

Answer: [ ] [1]

5. Which of the following is NOT a condition required for natural selection to occur?
A. Variation exists within the population.
B. Traits are heritable.
C. More offspring are produced than can survive.
D. Individuals consciously choose to adapt to their environment.

Answer: [ ] [1]

Section B: Structured Questions (Questions 6–15)

6. The Peppered Moth (Biston betularia) exists in two forms: light-colored and dark-colored (melanic).
In the 19th century, industrial pollution in England killed lichens on tree trunks and covered them in soot, turning the trees dark.

(a) Before industrialization, the light-colored moths were more common. Explain why, using the concept of camouflage.

_________________________________________________________________________ [2]

(b) During the industrial revolution, the population of dark-colored moths increased significantly. Explain this change in terms of natural selection.

_________________________________________________________________________ [3]

7. Darwin’s Finches on the Galapagos Islands show variations in beak size and shape.

(a) Define the term variation.

_________________________________________________________________________ [1]

(b) State two sources of variation in a population.

______________________________________________________________________ [2]

(c) On an island where the main food source is large, hard seeds, finches with larger, stronger beaks survived better than those with small beaks. Explain how this leads to speciation over a long period.

_________________________________________________________________________ [3]

8. The diagram below shows a timeline of horse evolution from Eohippus (50 million years ago) to the modern horse Equus.
(Diagram description: Shows a progression from a small, multi-toed animal to a large, single-hoofed animal.)

(a) Identify one trend in the evolution of the horse’s limbs.
_________________________________________________________________________ [1]

(b) Suggest one environmental change that might have driven this evolution.

_________________________________________________________________________ [1]

9. Compare homologous and analogous structures.

(a) Complete the table below.

Feature	Homologous Structures	Analogous Structures
Ancestry	Derived from a _______________ ancestor.	Derived from _______________ ancestors.
Function	May have _______________ or different functions.	Have _______________ functions.
Example	Human arm and whale flipper.	Bird wing and insect wing.

[3]

(b) Why do analogous structures not provide evidence for common ancestry?

_________________________________________________________________________ [1]

10. The graph below shows the change in average beak depth of a finch population during a drought.
(Graph description: X-axis is Time (Years), Y-axis is Average Beak Depth (mm). The line rises sharply during the drought years and stabilizes at a higher level afterwards.)

(a) Describe the relationship between the drought and beak depth.

_________________________________________________________________________ [1]

(b) Explain why the average beak depth did not return to its original size after the drought ended, assuming the large seeds remained available.

_________________________________________________________________________ [2]

11. Artificial selection is used by farmers to improve crop yields.

(a) Distinguish between artificial selection and natural selection.

_________________________________________________________________________ [2]

(b) Give one disadvantage of artificial selection in crops regarding genetic diversity.

_________________________________________________________________________ [1]

12. Fossils provide evidence for evolution.

(a) State two limitations of the fossil record.

______________________________________________________________________ [2]

(b) Despite these limitations, explain why fossils are still crucial evidence for evolution.

_________________________________________________________________________ [1]

13. A population of rabbits is introduced to an island with no predators. Initially, the population grows rapidly, then levels off.

(a) Name the type of growth curve shown.
_________________________________________________________________________ [1]

(b) Suggest two factors that caused the population to level off.

______________________________________________________________________ [2]

14. Molecular biology provides evidence for evolution through DNA sequencing.

(a) Explain why closely related species have more similar DNA sequences than distantly related species.

_________________________________________________________________________ [2]

(b) Why is cytochrome c (a protein involved in respiration) often used to compare evolutionary relationships?

_________________________________________________________________________ [1]

15. The diagram shows a phylogenetic tree of four species: A, B, C, and D.
(Diagram description: A and B branch from a recent node. C branches from an older node shared with A/B. D branches from the oldest node.)

(a) Which two species are most closely related?
_________________________________________________________________________ [1]

(b) Identify the most recent common ancestor of species A and C.
_________________________________________________________________________ [1]

Section C: Free Response Questions (Questions 16–20)

16. Explain how geographic isolation can lead to the formation of new species (allopatric speciation).

_________________________________________________________________________ [4]

17. "Evolution is not goal-oriented." Discuss this statement with reference to random mutations and environmental selection pressures.

_________________________________________________________________________ [3]

18. Describe the role of genetic drift in evolution, particularly in small populations.

_________________________________________________________________________ [2]

19. A new pesticide is introduced to control a pest insect. After 5 years, the pesticide is no longer effective.

(a) Explain this phenomenon using the principles of natural selection.

_________________________________________________________________________ [3]

(b) Suggest one strategy farmers could use to delay the development of resistance.
_________________________________________________________________________ [1]

20. Compare the evidence for evolution provided by the comparative anatomy of vertebrates and the comparative biochemistry of proteins.

_________________________________________________________________________ [4]

End of Quiz

Answers

Secondary 4 Pure Biology Quiz - Evolution Diversity (Answer Key)

Total Marks: 40

Section A: Multiple Choice Questions

1. B
[1]
Reasoning: Natural selection acts on existing variation; individuals with advantageous traits survive/reproduce more. A is Lamarckian; C is incorrect as rates vary; D is incorrect as mutations are random, not caused by need.

2. C
[1]
Reasoning: Same basic structure (bone arrangement) but different functions indicates common ancestry (homologous).

3. A
[1]
Reasoning: Mutation (variation) exists first -> Selection pressure (antibiotic) applied -> Survivors reproduce -> Population shifts.

4. B
[1]
Reasoning: Higher similarity in amino acid sequences implies fewer mutations have accumulated since divergence, indicating a more recent common ancestor.

5. D
[1]
Reasoning: Evolution is not conscious. A, B, and C are the three necessary conditions for natural selection.

Section B: Structured Questions

6. (a)

Light-colored moths blended in with the lichen-covered trees (camouflage).
Predators (birds) could not see them easily, so they survived and reproduced more than dark moths.
[2]

(b)

The trees became dark due to soot, making light moths visible to predators.
Dark moths were now camouflaged and had a survival advantage.
Dark moths survived predation, reproduced, and passed the dark allele to offspring.
Over time, the frequency of the dark allele increased in the population.
[3] (1 mark for survival advantage/camouflage, 1 mark for reproduction/passing alleles, 1 mark for change in allele frequency)

7. (a)

Differences in characteristics/features between individuals of the same species.
[1]

(b)

Mutation / Genetic recombination (meiosis/crossing over) / Sexual reproduction.
[2] (Any two)

(c)

Finches with larger beaks could crack hard seeds and survive; those with small beaks starved.
Large-beaked finches reproduced, passing the trait to offspring.
Over many generations, the population shifted to have larger beaks.
If isolated, this could lead to reproductive isolation and speciation.
[3]

8. (a)

Reduction in the number of toes (from multiple to one).
OR Increase in limb length/size.
[1]

(b)

Change from forest to grassland/prairie.
Need for faster running to escape predators in open terrain.
[1]

9. (a)

Homologous: Common ancestor; Same or different functions.
Analogous: Different ancestors; Same functions.
[3] (1 mark per correct blank, max 3)

(b)

They arise due to similar environmental pressures (convergent evolution), not shared ancestry.
[1]

10. (a)

As the drought progressed, the average beak depth increased.
[1]

(b)

The genetic variation for large beaks became fixed or more common in the gene pool.
Even if small seeds returned, the population had already evolved; or large seeds remained the dominant food source.
Evolution is not reversible in the short term without specific selection pressure against large beaks.
[2]

11. (a)

Artificial selection: Humans choose the traits; Natural selection: Environment chooses the traits.
Artificial selection is much faster.
[2]

(b)

Reduces genetic diversity/variations.
Makes the population vulnerable to diseases or environmental changes.
[1]

12. (a)

Fossilization is rare (requires specific conditions).
Soft tissues rarely fossilize.
Incomplete record (gaps in transitional forms).
[2] (Any two)

(b)

They show direct evidence of past life forms and transitional features linking groups.
They allow dating of evolutionary events.
[1]

13. (a)

Sigmoid (S-shaped) curve / Logistic growth.
[1]

(b)

Limited food/resources.
Accumulation of waste/toxins.
Disease/Competition.
[2] (Any two)

14. (a)

Mutations accumulate over time.
Closely related species diverged recently, so fewer mutations have accumulated, resulting in more similar sequences.
[2]

(b)

It is a fundamental protein found in almost all aerobic organisms.
It evolves slowly, allowing comparison across distant species.
[1]

15. (a)

A and B.
[1]

(b)

The node where the lineage leading to C diverges from the lineage leading to A and B.
[1]

Section C: Free Response Questions

16. Allopatric Speciation

A physical barrier (e.g., mountain, river) separates a population into two groups.
The two groups experience different environmental conditions/selection pressures.
Mutations occur randomly in each group.
Natural selection favors different traits in each group.
Over time, genetic differences accumulate.
Eventually, the groups become reproductively isolated (cannot interbreed) even if the barrier is removed.
[4] (1 mark per distinct point, max 4)

17. "Evolution is not goal-oriented"

Mutations are random; they do not occur because an organism "needs" them.
Natural selection acts on existing variation; it does not create traits.
Environmental changes are unpredictable; what is advantageous now may not be later.
Evolution has no end goal or perfect state; it is simply adaptation to current conditions.
[3]

18. Genetic Drift

Random changes in allele frequencies due to chance events (not selection).
Significant in small populations (e.g., bottleneck effect, founder effect).
Can lead to loss of alleles or fixation of harmful alleles purely by chance.
[2]

19. (a) Pesticide Resistance

Variation exists in the insect population; some have a mutation for resistance.
Pesticide kills non-resistant insects.
Resistant insects survive and reproduce.
Offspring inherit the resistance gene.
Over generations, the population becomes predominantly resistant.
[3]

(b) Strategy

Rotate pesticides with different modes of action.
Use biological control agents.
Leave untreated refuges for non-resistant insects to maintain susceptible genes.
[1]

20. Comparative Anatomy vs. Biochemistry

Anatomy: Looks at structural similarities (homologous structures). Good for visible traits but can be misleading due to convergent evolution (analogous structures).
Biochemistry: Compares DNA/protein sequences. More precise and quantitative. Can compare very different organisms (e.g., bacteria and humans).
Conclusion: Both support common ancestry, but biochemistry provides a molecular clock and resolves relationships where anatomy is ambiguous.
[4] (2 marks for describing each, 1 mark for comparison/limitation, 1 mark for synthesis)