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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:

Answer all questions.
Write your answers in the spaces provided.
The number of marks is given in brackets [ ] at the end of each question or part question.
This quiz covers the topic of Evolution and Diversity.

Section A: Multiple Choice Questions (10 Marks)

Choose the correct answer for each question.

1. Which of the following best defines biological evolution?
A. The change in an individual organism’s traits during its lifetime.
B. The change in the inherited characteristics of a population over generations.
C. The process by which organisms become perfectly adapted to their environment.
D. The migration of species from one habitat to another.
[1]

2. Fossils provide evidence for evolution. Which of the following is a limitation of using fossils as evidence?
A. Fossils cannot show the soft tissue structures of ancient organisms.
B. Fossils are only found in volcanic rock.
C. Fossils provide DNA sequences for all extinct species.
D. Fossils show that species have never changed over time.
[1]

3. In a population of beetles, green colouration is dominant (G) and brown colouration is recessive (g). If the environment changes such that brown beetles are better camouflaged, what is likely to happen to the frequency of the 'g' allele over time?
A. It will decrease.
B. It will remain constant.
C. It will increase.
D. It will disappear completely.
[1]

4. 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. Organisms produce more offspring than the environment can support.
D. Individuals consciously choose to adapt to their environment.
[1]

5. The forelimbs of humans, bats, and whales have similar bone structures but different functions. This is an example of:
A. Convergent evolution.
B. Homologous structures.
C. Analogous structures.
D. Artificial selection.
[1]

6. Antibiotic resistance in bacteria is a modern example of evolution. How does resistance arise in a bacterial population?
A. Bacteria learn to survive the antibiotic.
B. The antibiotic causes mutations in all bacteria.
C. Random mutations occur, and resistant bacteria survive and reproduce.
D. Bacteria share resistance genes only when exposed to antibiotics.
[1]

7. Which factor is most likely to lead to speciation (the formation of new species)?
A. Gene flow between two populations.
B. Geographic isolation of a population.
C. High rates of interbreeding.
D. Stable environmental conditions.
[1]

8. Darwin’s finches on the Galapagos Islands have different beak shapes. This variation is primarily due to:
A. Differences in the birds' diet and food sources.
B. Differences in the birds' singing abilities.
C. Random genetic drift only.
D. The birds choosing different mates based on beak size.
[1]

9. What is the role of mutation in evolution?
A. It ensures that all offspring are identical to the parents.
B. It provides the raw material for genetic variation.
C. It always results in harmful traits.
D. It occurs only in response to environmental stress.
[1]

10. Which of the following statements about natural selection is correct?
A. It acts on phenotypes, but evolution acts on genotypes.
B. It acts on genotypes, but evolution acts on phenotypes.
C. It creates new traits that an organism needs.
D. It guarantees the survival of the strongest individual.
[1]

Section B: Structured Questions (20 Marks)

11. The peppered moth (Biston betularia) exists in two forms: light-coloured and dark-coloured (melanic). Before the Industrial Revolution in England, light-coloured moths were common because they blended in with lichen-covered trees. During the Industrial Revolution, soot darkened the tree trunks, and the dark-coloured moths became more common.

(a) Explain why the dark-coloured moths became more common during the Industrial Revolution.

[2]

(b) After clean air laws were introduced and tree trunks became lighter again, the population of light-coloured moths increased. Explain this change using the principles of natural selection.

[2]

12. Figure 1 shows the skeletal structure of the forelimb of a human and a bat.

Image pending generation for this question.

(a) State the term used to describe structures that have a similar underlying anatomy but different functions.

[1]

(b) Explain how these structures provide evidence for evolution from a common ancestor.

[2]

[1]

13. A species of plant grows on a mountain slope. Plants at the bottom of the slope are tall with large leaves, while plants at the top are short with small, waxy leaves.

(a) Suggest one environmental factor that differs between the top and bottom of the mountain that could cause this variation.

[1]

(b) Explain how natural selection could lead to the short, waxy-leaved plants becoming dominant at the top of the mountain.

[3]

(c) If seeds from the top of the mountain are planted at the bottom, and they grow into tall plants with large leaves, is this variation genetic or environmental? Explain your answer.

[2]

14. Antibiotic resistance is a serious global health issue.

(a) Describe how the overuse of antibiotics accelerates the evolution of resistant bacteria.

[2]

(b) Suggest two strategies doctors can use to slow down the development of antibiotic resistance.

[2]

15. Galapagos tortoises on different islands have different shell shapes. On islands with lush vegetation close to the ground, tortoises have dome-shaped shells. On islands with sparse, high-growing cacti, tortoises have saddle-backed shells (raised front) that allow them to stretch their necks higher.

(a) Explain how geographic isolation contributed to the development of these two different shell shapes.

[3]

(b) Describe the process of natural selection that would lead to the saddle-backed shell becoming common on the island with high-growing cacti. Include the terms: variation, survival, reproduction, and alleles.

[4]

(c) If tortoises from the two different islands were brought together and could interbreed, what might happen to the distinct shell shapes over time? Explain your answer.

[3]

Section C: Application and Analysis (10 Marks)

16. A small population of birds is blown by a storm to a remote island where there are no other birds of that species. The founding population happens to have a higher frequency of blue feathers than the original mainland population, purely by chance.

(a) Name the evolutionary mechanism described in this scenario.

[1]

(b) Explain how this mechanism differs from natural selection.

[2]

17. Comparative biochemistry provides strong evidence for evolution. Scientists compare the amino acid sequences of haemoglobin in different species.

(a) What would you expect to find when comparing the haemoglobin sequence of humans and chimpanzees?

[1]

(b) What would you expect to find when comparing the haemoglobin sequence of humans and fish?

[1]

[3]

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

(a) Define artificial selection.

[1]

(b) Give one example of a trait in crops that might be selected for by farmers.

[1]

[3]

19. The concept of "Survival of the Fittest" is often misunderstood.

(a) In the context of evolution, what does "fitness" actually refer to?

[2]

(b) An organism may be physically strong but have low evolutionary fitness. Suggest a reason for this.

[2]

[1]

20. Evolution is an ongoing process.

(a) Why do some species appear to change very little over millions of years (e.g., the coelacanth)?

[2]

(b) If the environment changes rapidly, why might a species with low genetic variation be at risk of extinction?

[3]

End of Quiz

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Answers

Secondary 4 Combined Science Biology Quiz - Evolution Diversity (Answer Key)

Section A: Multiple Choice Questions

1. B
Explanation: Evolution is defined as the change in inherited characteristics of a population over generations, not changes in an individual.

2. A
Explanation: Fossilization usually preserves hard parts (bones, shells). Soft tissues decay rapidly and are rarely preserved, limiting our understanding of soft anatomy.

3. C
Explanation: If brown beetles are better camouflaged, they are less likely to be eaten. They survive and reproduce more, passing the 'g' allele to offspring, increasing its frequency.

4. D
Explanation: Natural selection is not a conscious choice. Individuals do not "choose" to adapt; those with advantageous traits survive by chance/nature.

5. B
Explanation: Homologous structures share a common evolutionary origin (same bone structure) but may have different functions (grasping, flying, swimming).

6. C
Explanation: Resistance arises from random mutations that exist before exposure. The antibiotic selects for these pre-existing resistant mutants.

7. B
Explanation: Geographic isolation prevents gene flow, allowing populations to diverge genetically until they can no longer interbreed (speciation).

8. A
Explanation: Beak shape is an adaptation to the specific food sources available on each island (e.g., hard seeds vs. insects vs. cactus flowers).

9. B
Explanation: Mutations are the primary source of new genetic variations (new alleles) upon which natural selection acts.

10. A
Explanation: Natural selection acts on the physical traits (phenotype) that affect survival. However, evolution is the change in the frequency of genes (genotypes/alleles) in the population.

Section B: Structured Questions

11. (a) Explanation: The soot darkened the trees, making light moths visible to predators. Dark moths were better camouflaged (1), so they survived predation and reproduced more, passing on the dark allele (1). (b) Explanation: With cleaner air, trees became lighter. Dark moths became visible to predators and were eaten (1). Light moths were better camouflaged, survived, and reproduced (1), increasing the frequency of the light allele.

12. (a) Homologous structures. [1] (b) Explanation: The similar bone arrangement suggests they inherited this structure from a common ancestor (1). Over time, natural selection modified the limbs for different functions (flying vs. grasping) in different environments (1). (c) Explanation: To support the wing membrane for flight / to reduce weight for flying. [1]

13. (a) Wind speed / Temperature / Soil depth / Water availability. (Any one valid abiotic factor). [1] (b) Explanation: There is variation in plant height/leaf size in the population (1). At the top, strong winds/cold favour short/waxy plants (less damage/water loss) (1). These plants survive and reproduce more successfully than tall plants (1). Over generations, the alleles for short/waxy traits become more common. (c) Explanation: This variation is environmental (phenotypic plasticity) (1). Because the genotype did not change, the plants expressed different traits based on the new environment (more resources/warmer at the bottom) (1). If it were genetic, they would remain short at the bottom.

14. (a) Explanation: Overuse kills susceptible bacteria, leaving only resistant mutants (1). These resistant bacteria reproduce without competition, passing resistance genes to the next generation, rapidly increasing the resistant population (1). (b) Strategies:

Only prescribe antibiotics for bacterial infections (not viral).
Ensure patients complete the full course of antibiotics. (Other valid answers: Rotate antibiotics, develop new drugs). [2]

15. (a) Explanation: The tortoises were separated by water (geographic barrier) preventing interbreeding (1). Each island had different environmental conditions (food sources) (1). This led to independent evolution in each population as they adapted to their specific local environment (1).

(b) Process of Natural Selection:

Variation: There was natural variation in shell shape and neck length in the ancestral tortoise population (1).
Survival: On the island with high cacti, tortoises with saddle-backed shells (longer neck reach) could access food better and were more likely to survive starvation (1).
Reproduction: These survivors reproduced and passed the alleles for saddle-backed shells to their offspring (1).
Alleles: Over many generations, the frequency of alleles for saddle-backed shells increased in the population, while dome-shell alleles decreased (1).

(c) Explanation: If they interbreed, gene flow would occur (1). The distinct alleles for shell shape would mix in the population (1). This might result in intermediate shell shapes or a loss of the distinct specialized traits, depending on the environment they are placed in (1).

Section C: Application and Analysis

16. (a) Genetic Drift (specifically Founder Effect). [1] (b) Explanation: Genetic drift is a change in allele frequency due to chance/random events (1), whereas natural selection is a change due to advantageous traits improving survival/reproduction (1). (c) Explanation: In small populations, chance events have a larger impact on the gene pool (1). The loss or fixation of alleles happens more quickly than in large populations where statistical averages hold true (1).

17. (a) Very few differences / Highly similar sequences. [1] (b) Many differences / Less similar sequences. [1] (c) Explanation: Species that are closely related share a more recent common ancestor (1). Therefore, they have had less time to accumulate mutations in their DNA/protein sequences (1). Greater similarity indicates closer evolutionary relationship (1).

18. (a) Definition: The process by which humans breed plants or animals for particular genetic traits (1). (b) Example: Larger fruit size / Higher yield / Disease resistance / Drought tolerance. (Any one). [1] (c) Explanation: Artificial selection often involves breeding from a small number of individuals with desired traits (1). This reduces the overall genetic diversity of the population (1). Low diversity makes the crop vulnerable to new diseases or environmental changes, as there may be no resistant alleles present (1).

19. (a) Explanation: Fitness refers to an organism's ability to survive and reproduce in its specific environment (1), passing its genes to the next generation (1). (b) Explanation: The organism may fail to find a mate, or may be sterile, or may die before reaching reproductive age despite being strong (1). If it does not reproduce, its fitness is zero (1). (c) Explanation: Natural selection drives evolution through the passing of genes. Physical strength only matters if it helps the organism reproduce; if an organism is strong but leaves no offspring, its traits are not passed on (1).

20. (a) Explanation: Their environment has remained stable (1), so there is no selective pressure forcing change. Their current traits are already well-adapted (stabilising selection) (1). (b) Explanation: Low genetic variation means there are fewer different alleles in the population (1). If the environment changes, there is a lower chance that any individual possesses a trait/allele that allows survival in the new conditions (1). Consequently, the whole population may die out (1).