- Which of the following best describes the term “speciation”?
A) The process of extinction of a species
B) The formation of new and distinct species in the course of evolution
C) The adaptation of species to their environment
D) The migration of species to new habitats
Answer: B) The formation of new and distinct species in the course of evolution
Explanation: Speciation is the evolutionary process by which populations evolve to become distinct species. It typically involves reproductive isolation, genetic divergence, and adaptation to different environments.
- What is the significance of homologous structures in evolutionary biology?
A) They indicate that species are unrelated.
B) They show that organisms can adapt to different environments.
C) They suggest common ancestry among different species.
D) They demonstrate the effects of natural selection.
Answer: C) They suggest common ancestry among different species.
Explanation: Homologous structures are anatomical features that share a common ancestry but may serve different functions in different species. Their similarities provide evidence for the evolutionary relationships among species.
- Which of the following types of natural selection favors individuals at both extremes of a phenotypic range?
A) Stabilizing selection
B) Directional selection
C) Disruptive selection
D) Artificial selection
Answer: C) Disruptive selection
Explanation: Disruptive selection occurs when individuals at both extremes of a phenotypic range have a higher fitness than individuals with intermediate traits. This type of selection can lead to speciation if the extremes become distinct over time.
- Which of the following is a characteristic of a r-strategist species?
A) Long lifespan
B) High parental investment
C) Many offspring with low survival rates
D) Slow population growth
Answer: C) Many offspring with low survival rates
Explanation: R-strategist species tend to produce a large number of offspring with low parental investment, leading to high mortality rates. They thrive in unstable environments where rapid reproduction is advantageous.
- Which mechanism of evolution is most likely to result in adaptive changes within a population over time?
A) Gene flow
B) Genetic drift
C) Natural selection
D) Mutation
Answer: C) Natural selection
Explanation: Natural selection is the primary mechanism that leads to adaptive changes in populations over time. It favors traits that enhance survival and reproductive success, gradually shaping the population to be better suited to its environment.
- The concept of genetic drift is most pronounced in which type of population?
A) Large, stable populations
B) Small, isolated populations
C) Migratory populations
D) Populations with high mutation rates
Answer: B) Small, isolated populations
Explanation: Genetic drift has a more significant impact on small, isolated populations because random events can lead to larger changes in allele frequencies compared to larger populations, where the effects of random sampling are minimized.
- Which of the following processes can lead to the development of new traits in a species?
A) Gene flow
B) Genetic drift
C) Mutations
D) All of the above
Answer: D) All of the above
Explanation: All the listed processes—gene flow, genetic drift, and mutations—can contribute to the development of new traits in a species. Mutations introduce new genetic material, gene flow can add variations, and genetic drift can change allele frequencies in a population.
- What is a possible outcome of polyploidy in plants?
A) Increased susceptibility to diseases
B) Increased genetic diversity and speciation
C) Decreased reproductive success
D) Loss of traits
Answer: B) Increased genetic diversity and speciation
Explanation: Polyploidy, the condition of having more than two complete sets of chromosomes, can lead to increased genetic diversity in plants. It can also result in speciation, as polyploid individuals may become reproductively isolated from their diploid relatives.
- Which of the following best describes the term “adaptive trait”?
A) A trait that enhances an organism’s ability to survive and reproduce in its environment
B) A trait that is beneficial only in certain environments
C) A trait that has no effect on an organism’s survival
D) A trait that is exclusively found in one species
Answer: A) A trait that enhances an organism’s ability to survive and reproduce in its environment
Explanation: An adaptive trait is a characteristic that improves an organism’s fitness, allowing it to survive and reproduce more effectively in its specific environment. These traits are favored by natural selection.
- Which of the following scenarios exemplifies coevolution?
A) A species of bird developing a long beak to feed on flowers with deep corollas
B) A population of rabbits becoming faster due to predation pressure from foxes
C) A species of fish developing resistance to pollution
D) A new species of plant emerging after a mass extinction event
Answer: A) A species of bird developing a long beak to feed on flowers with deep corollas
Explanation: Coevolution occurs when two or more species exert selective pressures on each other, leading to adaptations. The bird’s long beak evolves in response to the flower’s structure, which requires specific adaptations for feeding.
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