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Secondary 4 Pure Biology Evolution Diversity Quiz

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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 is given in brackets [ ].
This quiz covers the topic of Evolution and Diversity, including natural selection, variation, classification, and evidence for evolution.

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.

Image pending generation for this question.

What does the similarity in bone structure suggest about these three mammals?
A. They live in similar environments.
B. They share a common ancestor.
C. They use their limbs for the same function.
D. They evolved independently of each other.

Answer: [ ] [1]

3. Which of the following is an example of continuous variation in humans?
A. Blood group
B. Ability to roll tongue
C. Height
D. Presence of dimples

Answer: [ ] [1]

4. Antibiotic resistance in bacteria is a modern example of evolution. How does this occur?
A. Antibiotics cause bacteria to mutate and become resistant.
B. Bacteria learn to avoid antibiotics over time.
C. Resistant bacteria survive antibiotic treatment and reproduce.
D. All bacteria become resistant after exposure to antibiotics.

Answer: [ ] [1]

5. In the classification hierarchy, which group contains organisms that are most closely related?
A. Kingdom
B. Phylum
C. Genus
D. Family

Answer: [ ] [1]

Section B: Structured Questions (Questions 6–15)

6. Define the term variation.

_________________________________________________________________________ [1]

7. State two causes of variation in organisms.

_______________________________________________________________________ [2]

8. The peppered moth (Biston betularia) exists in two forms: light-colored and dark-colored.
Before the Industrial Revolution, light-colored moths were common because they camouflaged well against lichen-covered trees. During the Industrial Revolution, soot darkened the trees, and dark-colored moths became more common.

(a) Explain why the population of dark-colored moths increased during the Industrial Revolution.

_________________________________________________________________________ [2]

(b) Name the type of selection described in this scenario.
_________________________________________________________________________ [1]

9. Fig. 9.1 shows a phylogenetic tree of four species: A, B, C, and D.
(Imagine a tree where A and B branch from a recent node, C branches earlier, and D is the outgroup)

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

(b) Explain how you determined your answer from the diagram.

_________________________________________________________________________ [1]

10. Fossils provide evidence for evolution.
(a) Define the term fossil.

_________________________________________________________________________ [1]

(b) State one limitation of using fossils as evidence for evolution.

_________________________________________________________________________ [1]

11. Compare continuous and discontinuous variation by completing the table below.

Feature	Continuous Variation	Discontinuous Variation
Example in humans	(a) ___________________	(b) ___________________
Influence of environment	(c) ___________________	(d) ___________________

[4]

12. Scientists compare the amino acid sequences of hemoglobin in different species to determine evolutionary relationships.
Species X and Species Y have very similar hemoglobin sequences, while Species Z has a very different sequence.

(a) What does this suggest about the evolutionary relationship between Species X and Species Y?

_________________________________________________________________________ [1]

(b) Why do differences in amino acid sequences accumulate over time?

_________________________________________________________________________ [1]

13. Describe the role of mutations in evolution.

_________________________________________________________________________ [2]

14. The Galapagos finches have different beak shapes depending on the food available on their respective islands.
(a) Explain how natural selection led to the development of different beak shapes.

_________________________________________________________________________ [3]

15. State two pieces of evidence, other than fossils, that support the theory of evolution.

_______________________________________________________________________ [2]

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

16. Explain the difference between artificial selection and natural selection.

_________________________________________________________________________ [2]

17. A population of rabbits is introduced to an island with no predators. Initially, the population grows rapidly, but eventually, the growth rate slows down.
Explain this pattern of growth using the concept of competition.

_________________________________________________________________________ [2]

18. Why is genetic diversity important for the survival of a species when the environment changes?

_________________________________________________________________________ [2]

19. Describe how selective breeding has been used to improve crop plants. Give one specific example.

_________________________________________________________________________ [2]

20. "Evolution is just a theory, not a fact."
Using scientific evidence, explain why evolution is accepted as a scientific theory rather than just a guess.

_________________________________________________________________________ [2]

End of Quiz

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Answers

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

Total Marks: 40

Section A: Multiple Choice Answers

1. B
Explanation: Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It does not involve individuals changing during their lifetime (Lamarckism) or environmental induction of specific mutations.

2. B
Explanation: Homologous structures (similar bone arrangement) indicate common ancestry, even if the functions (grasping, flying, swimming) differ.

3. C
Explanation: Height is continuous variation (range of values, influenced by genetics and environment). Blood group, tongue rolling, and dimples are discontinuous (distinct categories).

4. C
Explanation: Antibiotics do not cause mutations; they select for pre-existing resistant mutants. Resistant bacteria survive, reproduce, and pass on the resistance gene.

5. C
Explanation: The classification hierarchy is Kingdom > Phylum > Class > Order > Family > Genus > Species. Organisms in the same Genus are more closely related than those in the same Family, Phylum, or Kingdom.

Section B: Structured Answers

6. Definition of variation:
Differences in characteristics between individuals of the same species. [1]

7. Causes of variation:

Genetic factors (mutations / meiosis / sexual reproduction). [1]
Environmental factors. [1]

8. Peppered Moth:
(a) Explanation:

Soot darkened the trees, making light moths visible to predators. [1]
Dark moths were better camouflaged, survived predation, and reproduced more, passing on the dark allele. [1]

(b) Type of selection:
Directional selection. [1]

9. Phylogenetic Tree:
(a) Most closely related:
Species A and Species B. [1]

(b) Explanation:
They share the most recent common ancestor (branch point/node) on the tree. [1]

10. Fossils:
(a) Definition:
Remains or traces of ancient organisms preserved in rock/sediment. [1]

(b) Limitation:

Fossil record is incomplete (not all organisms fossilize).
Soft tissues rarely fossilize.
Dating methods may have margins of error.
(Any one valid point) [1]

11. Continuous vs. Discontinuous Variation:
(a) Example Continuous: Height / Weight / Skin color. [1]
(b) Example Discontinuous: Blood group / Eye color (specific categories) / Tongue rolling. [1]
(c) Influence on Continuous: Significant influence (environment affects phenotype). [1]
(d) Influence on Discontinuous: Little or no influence (determined mainly by genetics). [1]

12. Amino Acid Sequences:
(a) Relationship:
Species X and Y are closely related and shared a common ancestor recently. [1]

(b) Accumulation of differences:
Mutations occur randomly in DNA over time, leading to changes in amino acid sequences. The longer since divergence, the more differences accumulate. [1]

13. Role of Mutations:

Mutations create new alleles/genetic variation. [1]
This variation provides the raw material for natural selection to act upon. [1]

14. Galapagos Finches:

Variation existed in beak shapes in the original population. [1]
Different islands had different food sources (e.g., hard seeds vs. insects). [1]
Finches with beak shapes suited to the local food survived and reproduced (natural selection). [1]
Over time, the population evolved distinct beak shapes. [1]
(Max 3 marks)

15. Other Evidence for Evolution:

Comparative anatomy (homologous structures). [1]
Molecular biology (DNA/protein sequence comparison). [1]
(Accept: Embryology, Biogeography)

Section C: Free Response Answers

16. Artificial vs. Natural Selection:

Natural Selection: Environment determines which traits are advantageous; process is slow; leads to adaptation to nature. [1]
Artificial Selection: Humans choose desirable traits; process is rapid; leads to traits useful to humans (e.g., high yield). [1]

17. Rabbit Population Growth:

Initially, resources (food/space) are abundant, so population grows exponentially. [1]
As population increases, competition for limited resources intensifies, causing the growth rate to slow (carrying capacity). [1]

18. Importance of Genetic Diversity:

High diversity means some individuals may possess alleles that allow survival in new conditions (e.g., disease, climate change). [1]
Low diversity increases the risk that the entire population will be wiped out by a single threat. [1]

19. Selective Breeding Example:

Humans select plants with desirable traits (e.g., larger fruit, disease resistance) to breed. [1]
Example: Breeding wheat for higher grain yield or drought resistance. [1]

20. Evolution as a Scientific Theory:

A scientific theory is a well-substantiated explanation supported by a vast body of evidence (fossils, DNA, anatomy). [1]
It is not a "guess"; it has been tested and confirmed through observation and experimentation over many years. [1]