Ziauddin University Medical Entry Test Biology Evolution Set 3

Ziauddin University Medical Entry Test Biology Evolution — Set 3

Question 1
Q1. What is the term for the process by which organisms become better suited to their environments?
- A) Natural selection
- B) Genetic drift
- C) Gene flow
- D) Mutation
Answer: Natural selection
Explanation: Natural selection drives adaptation, others are random or genetic changes.
Question 2
Q2. The evolution of the horse is an example of what type of evolutionary trend?
- A) Cope's rule
- B) Dollo's law
- C) Williston's law
- D) Gould's law
Answer: Cope's rule
Explanation: Cope's rule describes the trend towards increased body size, horse evolution is a classic example.
Question 3
Q3. What is the term for the idea that evolution occurs in rapid bursts followed by long periods of stability?
- A) Punctuated equilibrium
- B) Gradualism
- C) Saltationism
- D) Phyletic evolution
Answer: Punctuated equilibrium
Explanation: Punctuated equilibrium describes rapid evolution followed by stability, others describe continuous change.
Question 4
Q4. The fossil record shows that the evolution of whales from land-dwelling mammals occurred in a series of gradual steps. What type of evolution is this an example of?
- A) Punctuated equilibrium
- B) Gradualism
- C) Saltationism
- D) Phyletic evolution
Answer: Gradualism
Explanation: Gradualism describes continuous, slow evolution, whale evolution is a classic example.
Question 5
Q5. What is the term for the idea that evolution is driven by the interaction between organisms and their environments?
- A) Niche construction theory
- B) Gene-culture co-evolution
- C) Symbiogenesis
- D) Ecological genetics
Answer: Niche construction theory
Explanation: Niche construction theory describes the role of environment in evolution, others describe related concepts.
Question 6
Q6. As populations evolve, genetic drift acts on variation through what mechanism?
- A) Natural selection
- B) Gene flow
- C) Random sampling error
- D) Mutation
Answer: Random sampling error
Explanation: Genetic drift occurs due to random sampling error
Question 7
Q7. Which of the following types of speciation occurs when a new species emerges from an existing one without geographic isolation?
- A) Allopatric speciation
- B) Sympatric speciation
- C) Parapatric speciation
- D) Peripatric speciation
Answer: Sympatric speciation
Explanation: Sympatric speciation occurs without geographic isolation
Question 8
Q8. A fossil record shows a sudden appearance of complex life forms. What is this phenomenon called?
- A) Cambrian explosion
- B) Mass extinction
- C) Gradualism
- D) Punctuated equilibrium
Answer: Cambrian explosion
Explanation: Cambrian explosion refers to sudden appearance of complex life
Question 9
Q9. A species has a high degree of genetic variation. What is the primary advantage of this variation?
- A) Increased susceptibility to disease
- B) Reduced ability to adapt to changing environments
- C) Increased fitness in a stable environment
- D) Increased potential for evolution
Answer: Increased potential for evolution
Explanation: Genetic variation increases potential for evolution
Question 10
Q10. Which of the following statements about homologous structures is true?
- A) They have similar functions but different anatomy
- B) They have different functions but similar anatomy
- C) They have similar functions and similar anatomy
- D) They are found only in closely related species
Answer: They have different functions but similar anatomy
Explanation: Homologous structures have similar anatomy but different functions
Question 11
Q11. A population has a high frequency of a particular allele. What can be inferred about this allele?
- A) It is deleterious and will be selected against
- B) It is neutral and has no effect on fitness
- C) It is beneficial and has been selected for
- D) It is a new mutation and has not yet been selected for
Answer: It is beneficial and has been selected for
Explanation: High frequency allele is likely beneficial
Question 12
Q12. Which of the following statements about analogous structures is true?
- A) They have similar functions but different anatomy
- B) They have different functions but similar anatomy
- C) They have similar functions and similar anatomy
- D) They are found only in closely related species
Answer: They have similar functions but different anatomy
Explanation: Analogous structures have similar functions but different anatomy
Question 13
Q13. What is the term for the process by which a new species emerges from an existing one through geographic isolation?
- A) Allopatric speciation
- B) Sympatric speciation
- C) Parapatric speciation
- D) Peripatric speciation
Answer: Allopatric speciation
Explanation: Allopatric speciation occurs through geographic isolation
Question 14
Q14. A fossil record shows a gradual change in the characteristics of a species over time. What is this phenomenon called?
- A) Gradualism
- B) Punctuated equilibrium
- C) Mass extinction
- D) Cambrian explosion
Answer: Gradualism
Explanation: Gradualism refers to gradual change in characteristics
Question 15
Q15. What is the term for the ability of an organism to survive and reproduce in a particular environment?
- A) Fitness
- B) Adaptation
- C) Natural selection
- D) Genetic drift
Answer: Fitness
Explanation: Fitness refers to ability to survive and reproduce
Question 16
Q16. A population has a high degree of gene flow. What can be inferred about this population?
- A) It is genetically diverse
- B) It is genetically uniform
- C) It is in genetic equilibrium
- D) It is undergoing speciation
Answer: It is genetically uniform
Explanation: High gene flow leads to genetic uniformity
Question 17
Q17. In a population of finches on an island, a severe drought leads to a scarcity of small seeds, resulting in the survival of finches with larger beaks. What is the primary mechanism driving this evolutionary change?
- A) Genetic drift due to the bottleneck effect
- B) Natural selection acting on beak size
- C) Mutation introducing a new beak size gene
- D) Gene flow from a neighboring island
Answer: Natural selection acting on beak size
Explanation: Natural selection favors larger beaks, most tempting wrong option fails as genetic drift is random.
Question 18
Q18. A species of bird undergoes a rapid evolutionary change in response to a change in its environment. Which of the following is the most likely reason for this rapid evolution?
- A) A sudden mutation in a key gene
- B) Genetic variation already present in the population
- C) Introduction of a new species that competes for resources
- D) Change in the species' migration pattern
Answer: Genetic variation already present in the population
Explanation: Pre-existing variation allows for quick adaptation, most tempting wrong option fails as mutation is rare.
Question 19
Q19. In a study of the evolution of antibiotic resistance in bacteria, researchers find that resistance is more likely to develop in bacteria that are exposed to low levels of antibiotics. What is the primary mechanism driving this evolutionary change?
- A) Horizontal gene transfer from resistant bacteria
- B) Natural selection acting on pre-existing genetic variation
- C) Mutation introducing a new resistance gene
- D) Genetic drift due to the bottleneck effect
Answer: Natural selection acting on pre-existing genetic variation
Explanation: Natural selection favors resistant bacteria, most tempting wrong option fails as mutation is less common.
Question 20
Q20. A group of scientists are studying the evolution of a particular trait in a population of animals. They find that the trait is influenced by multiple genes, each with a small effect. What is the most likely explanation for the evolution of this trait?
- A) A single mutation with a large effect
- B) Polygenic inheritance with multiple genes contributing
- C) Epigenetic factors influencing gene expression
- D) Gene-environment interaction
Answer: Polygenic inheritance with multiple genes contributing
Explanation: Polygenic inheritance explains small effect sizes, most tempting wrong option fails as single mutation is rare.