PCB 4674- Final Exam Study Guide - Questions with
Correct Answers (Verified Update)
100 questions with answers
Topic: PCB 4674- Final Exam Study Guide
1. A definition of species as the smallest group of individuals that share a common
ancestor, forming one branch on the tree of life.
Answer: Phylogenetic Species Concept
2. A definition of species in terms of measurable anatomical criteria.
Answer: Morphological Species Concept
3. Definition of a species as a population or group of populations whose members
have the potential to interbreed in nature and produce viable, fertile offspring, but
are not able to produce viable, fertile offspring with members of other populations.
Answer: Biological Species Concept
4. Describes factors that prevent the fertilization of an egg.
Answer: Pre-zygotic Isolation
5. Species occur in the same area, but they occupy different habitats and rarely
encounter each other
Answer: Ecological Isolation
6. Form of reproductive isolation in which two populations reproduce at different
times
Answer: Temporal Isolation
7. Form of reproductive isolation in which two populations have differences in
courtship rituals or other types of behavior that prevent them from interbreeding
Answer: Behavioral Isolation
8. Morphological differences prevent fertilization.
Answer: Mechanical Isolation
9. Type of premating barrier in which different plants use different pollinators
Answer: Pollinator Isolation
10. Sperm of one species may not be able to fertilize eggs of another species
Answer: Gametic Isolation
11. Reproductive isolation that occurs after members of two different species have
mated and produced a hybrid offspring. Such hybrids are usually unable to
reproduce
Answer: Postzygotic Isolation
12. A postzygotic barrier in which hybrid zygotes fail to develop or to reach sexual
maturity.
Answer: Hybrid Inviability
13. Hybrid offspring mature but are sterile as adults
Answer: Hybrid Sterility
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, 14. Hybrid is fertile, but when they breed the next generation is sterile.
Answer: Hybrid Breakdown
15. The formation of new and distinct species in the course of evolution.
Answer: Speciation
16. The formation of new species in populations that are geographically isolated
from one another.
Answer: Allopatric Speciation
17. Initial: - Populations isolated from each other - No gene flow possible Changes: -
Populations diverge and become distinct Immediate Outcomes: - 2 distinct
populations - Populations coalesce into a single species upon secondary contact -
3rd species arrises from hybridization - Reinforcement to prevent hybridization
occurs at 2nd contact.
Answer: Allopatric Speciation conditions
18. The formation of new species in populations that live in the same geographic
area.
Answer: Sympatric Speciation
19. Initial: - Only 1 population located in a single location - Gene flow possible
Changes: - Some members of population have high degree of reproductive isolation
from other members Immediate Outcomes: - 2 distinct species occupy same area
Answer: Sympatric Speciation conditions
20. Speciation pattern in which populations speciate while in contact along a
common border
Answer: Parapatric Speciation
21. Initial: - Adjactent to one another and gene flow is possible Changes: -
Populations diverge and accumulate differences, due to different selection regimes
driven by different habitats Outcomes: - 2 species with adjacent range boundaries
but different ecological niches
Answer: Parapatric Speciation conditions
22. Natural selection that results in assortative mating in recently diverged
populations in secondary contact; also known as reproductive character
displacement.
Answer: Reinforcement
23. Model of how gene variants sampled from a population may have originated from
a common ancestor.
Answer: Parental Population Coalescence
24. Forms because habitat is favorable to hybrids.
Answer: Stable Hybrid Zone
25. How old is the Earth?
Answer: 4.6 billion years old
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Correct Answers (Verified Update)
100 questions with answers
Topic: PCB 4674- Final Exam Study Guide
1. A definition of species as the smallest group of individuals that share a common
ancestor, forming one branch on the tree of life.
Answer: Phylogenetic Species Concept
2. A definition of species in terms of measurable anatomical criteria.
Answer: Morphological Species Concept
3. Definition of a species as a population or group of populations whose members
have the potential to interbreed in nature and produce viable, fertile offspring, but
are not able to produce viable, fertile offspring with members of other populations.
Answer: Biological Species Concept
4. Describes factors that prevent the fertilization of an egg.
Answer: Pre-zygotic Isolation
5. Species occur in the same area, but they occupy different habitats and rarely
encounter each other
Answer: Ecological Isolation
6. Form of reproductive isolation in which two populations reproduce at different
times
Answer: Temporal Isolation
7. Form of reproductive isolation in which two populations have differences in
courtship rituals or other types of behavior that prevent them from interbreeding
Answer: Behavioral Isolation
8. Morphological differences prevent fertilization.
Answer: Mechanical Isolation
9. Type of premating barrier in which different plants use different pollinators
Answer: Pollinator Isolation
10. Sperm of one species may not be able to fertilize eggs of another species
Answer: Gametic Isolation
11. Reproductive isolation that occurs after members of two different species have
mated and produced a hybrid offspring. Such hybrids are usually unable to
reproduce
Answer: Postzygotic Isolation
12. A postzygotic barrier in which hybrid zygotes fail to develop or to reach sexual
maturity.
Answer: Hybrid Inviability
13. Hybrid offspring mature but are sterile as adults
Answer: Hybrid Sterility
Page 1
, 14. Hybrid is fertile, but when they breed the next generation is sterile.
Answer: Hybrid Breakdown
15. The formation of new and distinct species in the course of evolution.
Answer: Speciation
16. The formation of new species in populations that are geographically isolated
from one another.
Answer: Allopatric Speciation
17. Initial: - Populations isolated from each other - No gene flow possible Changes: -
Populations diverge and become distinct Immediate Outcomes: - 2 distinct
populations - Populations coalesce into a single species upon secondary contact -
3rd species arrises from hybridization - Reinforcement to prevent hybridization
occurs at 2nd contact.
Answer: Allopatric Speciation conditions
18. The formation of new species in populations that live in the same geographic
area.
Answer: Sympatric Speciation
19. Initial: - Only 1 population located in a single location - Gene flow possible
Changes: - Some members of population have high degree of reproductive isolation
from other members Immediate Outcomes: - 2 distinct species occupy same area
Answer: Sympatric Speciation conditions
20. Speciation pattern in which populations speciate while in contact along a
common border
Answer: Parapatric Speciation
21. Initial: - Adjactent to one another and gene flow is possible Changes: -
Populations diverge and accumulate differences, due to different selection regimes
driven by different habitats Outcomes: - 2 species with adjacent range boundaries
but different ecological niches
Answer: Parapatric Speciation conditions
22. Natural selection that results in assortative mating in recently diverged
populations in secondary contact; also known as reproductive character
displacement.
Answer: Reinforcement
23. Model of how gene variants sampled from a population may have originated from
a common ancestor.
Answer: Parental Population Coalescence
24. Forms because habitat is favorable to hybrids.
Answer: Stable Hybrid Zone
25. How old is the Earth?
Answer: 4.6 billion years old
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