A Level H1 Biology Evolution Diversity Quiz

Answer Key - A-Level Biology H1 Quiz: Evolution Diversity

1. Natural Selection [2]

• The process by which organisms with favorable traits are more likely to survive and reproduce (1).
• These traits are passed to the next generation, increasing the frequency of these alleles in the population (1).

2. Sources of Genetic Variation [2]

• Random mutation (1).
• Meiosis (crossing over/independent assortment) OR Random fertilization (1).

3. Homologous vs. Analogous [2]

• Homologous: Structures with similar anatomy/origin but different functions (e.g., pentadactyl limb) (1).
• Analogous: Structures with similar functions but different evolutionary origins (e.g., wings of insect vs. bird) (1).

4. Incomplete Fossil Record [2]

• Not all organisms possess hard parts (bones/shells) that fossilize (1).
• Many fossils are destroyed by geological processes or remain undiscovered (1).

5. Role of Mutations [3]

• Mutations create new alleles/genetic variation (1).
• This provides the raw material upon which natural selection can act (1).
• Beneficial mutations increase fitness and are preserved in the population (1).

6. Individuals vs. Populations [2]

• Evolution is a change in allele frequencies of a population over generations (1).
• An individual's genotype is fixed at birth and does not change in response to selection (1).

7. Divergent vs. Convergent [2]

• Divergent: Related species evolve different traits due to different pressures (1).
• Convergent: Unrelated species evolve similar traits due to similar environmental pressures (1).

8. Molecular Evidence [3]

• Morphology can be misleading due to convergent evolution (analogous structures) (1).
• Amino acid sequences provide a quantitative measure of similarity (1).
• Fewer differences in sequences indicate a more recent common ancestor (1).

9. Beetle Population Shift [4]

• Variation in color exists in the population (1).
• Brown beetles are better camouflaged against brown foliage, reducing predation (1).
• Brown beetles survive longer and reproduce more successfully (1).
• Frequency of "brown" alleles increases in subsequent generations (1).

10. Adaptive Radiation [3]

• Rapid evolution of many species from a single common ancestor (1).
• Occurs when organisms occupy different ecological niches (1).
• Example: Darwin's Finches evolving different beak shapes for different food sources (1).

11. Antibiotic Resistance [4]

• Variation exists; some bacteria have mutations for resistance (1).
• Antibiotics act as a selection pressure, killing susceptible bacteria (1).
• Resistant bacteria survive and multiply (1).
• The population evolves to be predominantly antibiotic-resistant (1).

12. Genetic Drift vs. Natural Selection [3]

• Natural selection is non-random and based on fitness/adaptation (1).
• Genetic drift is a random change in allele frequencies (1).
• Drift is more pronounced in small populations (1).

13. Speciation [2]

• The formation of new and distinct species in the course of evolution (1).
• Allopatric and Sympatric speciation (1).

14. Reproductive Isolation [3]

• Prevents interbreeding between two populations (1).
• Prevents gene flow between the groups (1).
• Allows the populations to diverge genetically until they can no longer produce fertile offspring (1).

15. Three Domains [2]

• Bacteria, Archaea, Eukarya (1).
• Bacteria have peptidoglycan in cell walls; Archaea do not (or differences in membrane lipids/RNA polymerase) (1).

16. Dichotomous Key [2]

• A tool used to identify organisms based on a series of choices between two alternative characteristics (1).
• Allows for systematic and objective identification of unknown specimens (1).

17. Fungi vs. Plantae [3]

• Nutrition: Fungi are saprotrophs/heterotrophs; Plants are autotrophs (photosynthetic) (1).
• Cell Wall: Fungi have chitin; Plants have cellulose (1).
• (Any correct pairing of the two) (1).

18. Morphological to Phylogenetic [3]

• Morphology can be deceptive due to convergence (1).
• Phylogenetics uses DNA/protein sequences to determine actual evolutionary relationships (1).
• Provides a more accurate "tree of life" based on genetic heritage (1).

19. Allopatric Speciation [5]

• A population is split by a geographic barrier (e.g., mountain, river) (1).
• The two populations are physically isolated, preventing gene flow (1).
• Each population faces different selection pressures/mutations (1).
• Genetic differences accumulate over time (1).
• Eventually, they become reproductively isolated and cannot interbreed even if the barrier is removed (1).

20. Vestigial Structures [3]

• Structures that have lost their original function (e.g., human appendix) (1).
• Suggests the organism evolved from an ancestor where the structure was functional (1).
• Evidence of a transition from one form to another over time (1).