From Real Exams Quiz
A Level H1 Biology Evolution Diversity Quiz
Free A Level H1 Biology Evolution Diversity quiz, HY3 Exam version, with questions, answers, and A Level-style practice for Singapore students.
These static practice materials are generated from the site's syllabus and paper-generation workflow, with source and model context shown so students and parents can evaluate the material before use.
Questions
Free quiz and exam paper access
Enter your details to view this paper
Your access is remembered on this device.
Answers
A-Level Biology H1 Quiz - Evolution Diversity: Answer Key
Total Marks: 40
Topic: Evolution & Diversity
Section A: Multiple Choice
1. B (1 mark)
Teaching note: The biological species concept (Mayr) defines species as groups of actually or potentially interbreeding natural populations reproductively isolated from others. A is niche concept; C is morphological; D is geographic.
2. B (1 mark)
Teaching note: Directional selection favours one extreme phenotype (dark) after environmental change (dark soil). Genetic drift is random; stabilising favours intermediate; disruptive favours both extremes.
3. B (1 mark)
Teaching note: Homologous structures (e.g., forelimbs of vertebrates) indicate common ancestry despite different functions. Convergent evolution gives analogous structures.
4. C (1 mark)
Teaching note: Hardy–Weinberg requires large population (no drift). Small population violates condition. H1 does not calculate but should know assumptions: no mutation, random mating, no migration, large population, no selection.
5. B (1 mark)
Teaching note: Resistance arises from variation; antibiotics select survivors that reproduce. Not vaccine use or Lamarckian.
Section B: Structured Short Answers
6. (2 marks)
- Mutation (1)
- Sexual reproduction / recombination / meiosis (1)
Teaching: Variation sources include random mutation and allele shuffling during reproduction.
7. (2 marks)
Convergent evolution: unrelated species face similar environmental pressures (1) and independently evolve similar traits for same function (1). Example not needed but analogous wings of bird/insect.
8. (2 marks)
Any one: comparative anatomy / homologous structures / molecular biology (DNA/protein similarity) / biogeography / direct observation (e.g., antibiotic resistance). (2 for naming + brief)
9. (2 marks)
Reproductive isolation = members of different populations cannot interbreed to produce fertile offspring (2). Or barrier to gene flow.
10. (2 marks)
One reason: habitat loss / temperature shift beyond tolerance / new predator / food source removed (2 with explanation).
Section C: Data-Based and Extended Response
11. (4 marks total)
(a) % increase = (10.4 – 9.1) / 9.1 × 100 = 1.3 / 9.1 × 100 ≈ 14.3% (2 marks: 1 for method, 1 for answer)
(b) Drought reduced small seeds; birds with deeper beaks accessed remaining food, survived, reproduced → directional selection (2 marks).
12. (3 marks)
Strain Y survives at high antibiotic concentration while X dies (1); antibiotic acts as selective agent (1); resistant alleles increase in population (1). Ref to graph needed.
13. (3 marks)
Homologous: same origin, different function (e.g., human arm / whale flipper) (1.5). Analogous: different origin, same function (e.g., insect wing / bird wing) (1.5).
14. (3 marks)
(a) A–B (1).
(b) Fewer differences = closer relation (1); molecular similarity supports common ancestry (1).
15. (3 marks)
Fossils show chronological sequence (1); transitional forms (1); extinct intermediates link groups (1). E.g., Archaeopteryx.
16. (3 marks)
(a) Directional (1).
(b) Dark allele frequency increases (1); light allele decreases due to predation (1).
17. (3 marks)
River separates P and Q (1); no gene flow (1); independent mutation/selection → reproductive isolation (1).
18. (3 marks)
Mutation creates variation (1); selection favours beneficial alleles (1); repeated over generations → adaptation (1).
19. (2 marks)
Bacteria reproduce asexually (1); species concept based on interbreeding not applicable / horizontal gene transfer (1).
20. (3 marks)
(a) Adaptive radiation from common ancestor (1); different beaks for different food (1).
(b) Compare DNA sequences / phylogenetic tree (1).