Genetics Quiz 1

Genetics Quiz

Genetics Quiz #1

Mendel’s Laws: 1. Principle of Segregation: Two members of a gene pair segregate from each other in the formation of gametes; half the gametes carry one allele, and the other half carry the other allele What it means: each gene has two copies (alleles) and a parent will give only one copy to a child. The other parent will give another copy, and thus the child will receive two copies (alleles) – one from each parent. Each child will literally be half-mom and half-dad!

1. According to the biological species concept, horses and donkeys are not considered in the same species because

  • A) they never mate.
  • B) they do not produce fertile offspring.
  • C) they look different.
  • D) they do not share a relatively recent common ancestor.
ANS: {B}  they do not produce fertile offspring.


2. Semispecies are

  • A) samples of fossils that look rather different, although we cannot be sure if they were indeed different species.
  • B) populations that are partially, but not completely, reproductively isolated from each other.
  • C) species that have split off from a common ancestor, and then later merged back together to form a single species.
  • D) species that are on the verge of becoming extinct.
ANS: {B}  populations that are partially, but not completely, reproductively isolated from each other


3. How many human species exist today?

  • A) 1
  • B) 3
  • C) 5
  • D) We do not know.
ANS: {A} 1


4. The transformation of a species over time is known as

  • A) polygenesis.
  • B) monogenesis.
  • C) cladogenesis.
  • D) anagenesis.
ANS: {D} anagenesis.


5. A chronospecies is) 

  • a) population that will eventually become a new species, given enough time.
  • B) a species that, though reproductively isolated, looks exactly like another species.
  • C) a label used for a stage of a single species evolving over time.
  • D) a measure of how many new species appear in a given period of time.
ANS: {C} a label used for a stage of a single species evolving over time.


6. The origin of a new species first requires

  • A) reduced gene flow.
  • B) increased gene flow.
  • C) reduced mutation rates.
  • D) increased mutation rates.
ANS: {A} reduced gene flow.


7. Someone comes up to you and states that an early species of ape could not have evolved into the first humans because both apes and humans are alive today. This person has failed to grasp the nature of

  • A) polygenesis.
  • B) monogenesis.
  • C) cladogenesis.
  • D) anagenesis.
ANS: {C} cladogenesis.


8. ________________ is when a species gives rise to a new and separate species.

  • A) Polygenesis.
  • B) Monogenesis.
  • C) Cladogenesis.
  • D) Anagenesis.
ANS: {C} Cladogenesis.


9. _______________ acts to inhibit reproductive isolation.

  • A) Mutation
  • B) Natural selection
  • C) Genetic drift
  • D) Gene flow
ANS: {D} Gene flow


10. When we place fossil specimens into different species based on their physical appearance, we are using the ___________ concept.

  • A) biological species
  • B) paleospecies
  • C) anagenetic species
  • D) monospecies
ANS: {B}  paleospecies


11. Rapid speciation following the availability of new environments is known as

  • A) gradualism.
  • B) adaptive radiation.
  • C) species selection.
  • D) punctuated equilibrium.
ANS: {B}  adaptive radiation.


12. In your study of the fossil record of early mammals, you notice a changing environment is followed by the initial appearance of a tree-climbing species, which is then followed by many later tree-climbing species. This is an example of

  • A) anagenesis.
  • B) gradualism.
  • C) species selection.
  • D) adaptive radiation.
ANS: {D} adaptive radiation.


13. According to the idea of gradualism, macroevolution usually involves

  • A) slow and gradual change.
  • B) most species becoming extinct in a relatively short time.
  • C) alternating periods of stasis (no change) and rapid change.
  • D) species selection.
ANS: {A} slow and gradual change.


14. According to the idea of punctuated equilibrium, macroevolution usually involves

  • A) slow and gradual change.
  • B) alternating periods of stasis (no change) and rapid change.
  • C) most species becoming extinct in a relatively short time.
  • D) species selection.
ANS: {B} alternating periods of stasis (no change) and rapid change.


15. How common has extinction been in the fossil record?

  • A) Over 99 percent of all past species have become extinct.
  • B) Roughly 50 percent of all past species have become extinct.
  • C) Roughly 25 percent of all past species have become extinct.
  • D) Very few species have ever become extinct.
ANS: {A} Over 99 percent of all past species have become extinct.


16. A mass extinction is

  • A) the extinction of small-sized species.
  • B) the extinction of large-sized species.
  • C) the simultaneous extinction of many species.
  • D) something that has never been seen in the fossil record.
ANS: {C}  the simultaneous extinction of many species.


17. The idea that evolution will continue in the same direction is known as orthogenesis. This idea

  • A) is always correct.
  • B) is incorrect—not all structures continue to change in the same direction.
  • C) is correct for all organisms except for humans.
  • D) is also known as natural selection.
ANS: {B}  is incorrect—not all structures continue to change in the same direction.

18. The idea that natural selection will always select for larger organisms (“bigger is better”)

  • A) is totally supported by both the fossil evidence and field studies of living species.
  • B) fails to consider the fact that smaller individuals often require less food and are therefore sometimes at an advantage.
  • C) fails to consider the fact that smaller individuals often have an advantage in terms of disease resistance.
  • D) is true for mammals and reptiles, but seldom for other groups of animals.
ANS: {B} fails to consider the fact that smaller individuals often require less food and are therefore sometimes at an advantage.


19. The more recent a trait has evolved

  • A) the “better” it is in an evolutionary sense.
  • B) the more quickly a species will become extinct.
  • C) the more likely the effect of genetic drift.
  • D) has no bearing on its worth compared with other traits that are older.
ANS: {D} has no bearing on its worth compared with other traits that are older.


20. Natural selection

  • A) always works.
  • B) always produces perfect structures.
  • C) always leads to an increase in size.
  • D) None of these.
ANS: {D} None of these.


21. Groups within a species that are physically distinct but are still capable of interbreeding are often classified as

  • A) subspecies.
  • B) semispecies.
  • C) quasispecies.
  • D) pseudo species.
ANS: {A} subspecies.


22. Homology refers to

  • A) similarity due to descent from a common ancestor.
  • B) the independent development of similar structures in unrelated species.
  • C) two species having the same number of chromosomes.
  • D) anatomical structures are seen in humans but not found in other primate species.
ANS: {A}  similarity due to descent from a common ancestor.


23. The independent evolution of similar traits in two species is known as

  • A) homology.
  • B) homoplasy.
  • C) acquired characteristics (Lamarck’s hypothesis).
  • D) cladogenesis.
ANS: {B} homoplasy.


24. Parallel evolution and convergent evolution are examples of

  • A) speciation.
  • B) homology.
  • C) homoplasy.
  • D) punctuated equilibrium.
ANS: {C}  homoplasy.


25. Parallel evolution is the independent evolution of the same trait in

  • A) closely related species.
  • B) distantly related species.
  • C) males and females within the same species.
  • D) mammalian and reptilian species.
ANS: {A} closely related species.


26. Convergent evolution is the independent evolution of the same trait in

  • A) closely related species.
  • B) distantly related species.
  • C) males and females within the same species.
  • D) mammalian and reptilian species.
ANS: {B} distantly related species.


27. The limbs of humans and many other vertebrates consist of an upper limb bone and two lower limb bones. This similarity among many vertebrates is an example of

  • A) convergent evolution.
  • B) parallel evolution.
  • C) homoplasy.
  • D) homology.
ANS: {D} homology.


28. Both birds and insects have wings that they use to fly. Here, wings are an example of

  • A) homology.
  • B) homoplasy.
  • C) adaptive radiation.
  • D) neutral traits.
ANS: {B} homoplasy. 


29. An example of a primitive trait in modern humans is

  • A) five digits on hands and feet.
  • B) a large brain.
  • C) small canine teeth.
  • D) tool use.
ANS: {A}  five digits on hands and feet.


30. An example of a derived trait in humans (compared to apes) is

  • A) forward-facing eyes.
  • B) five digits on hands and feet.
  • C) the number of molar teeth.
  • D) upright walking.
ANS: {D} upright walking.