ASU BIO182 GENERAL
BIOLOGY II EXAM 2
PRACTICE EXAM
Question 1: Which statement best describes the biological species concept?
Choices:
1) A species is a group of organisms that looks nearly identical 2) A species is a group whose members can interbreed and produce fertile o�spring under natural conditions 3) A species is any group occupying the same habitat 4) A species is any lineage with the same chromosome number Correct Answer: A species is a group whose members can interbreed and produce fertile o�spring under natural conditions Explanation: The biological species concept de�nes species by reproductive compatibility and reproductive isolation from other groups.Page 1
Question 2: Two bird populations live on opposite sides of a newly formed canyon and no longer exchange genes. Which process has begun?
Choices:
1) Allopatric speciation 2) Sympatric speciation 3) Arti�cial selection 4) Convergent evolution
Correct Answer: Allopatric speciation
Explanation: A geographic barrier that interrupts gene �ow can initiate allopatric speciation.
Question 3: Which situation is the best example of sympatric speciation?
Choices:
1) A river separates one rodent population into two 2) A plant lineage becomes polyploid and can no longer breed with nearby diploid plants 3) A storm carries lizards to a distant island 4) A glacier divides a forest population Correct Answer: A plant lineage becomes polyploid and can no longer breed with nearby diploid plants Explanation: Sympatric speciation occurs without a geographic barrier; polyploidy can create immediate reproductive isolation in plants.Page 2
Question 4: A mating song di�erence prevents two closely related frog species from mating. This is what type of isolating mechanism?
Choices:
1) Hybrid breakdown 2) Behavioral prezygotic isolation 3) Reduced hybrid fertility 4) Temporal postzygotic isolation
Correct Answer: Behavioral prezygotic isolation
Explanation: Behavioral di�erences that prevent mating act before fertilization and are therefore prezygotic barriers.Question 5: Two plant species release pollen at di�erent times of year. What reproductive barrier is operating?
Choices:
1) Temporal isolation 2) Mechanical isolation 3) Hybrid sterility 4) Gametic isolation
Correct Answer: Temporal isolation
Explanation: Breeding at di�erent times prevents mating or fertilization and is a prezygotic temporal barrier.Page 3