Question

1. Which of the following is true of a population that is evolving by means of natural selection? (1 point)
A.)Acquired characteristics are passed down from parent to offspring.
B.)Organisms best adapted to their environment have the highest fitness.
C.)Allele frequencies of all mutations are continuously increasing.
D.)Alleles become more or less common in the population through a series of chance occurrences.

2. Which of the following explains the relationship between alleles and natural selection? (1 point)
A.) Alleles control an organism’s genotype. Natural selection works directly on the genotype.
B. )Alleles control an organism’s genotype. Natural selection works directly on the phenotype.
C.) Alleles control an organism’s phenotype. Natural selection works directly on the genotype.
D.)Alleles control an organism’s phenotype. Natural selection works directly on the phenotype.

3. Which of the following must occur in order for speciation to take place? (1 point)
A.) Populations within a species must be reproductively isolated.
B.)Populations within a species must be geographically isolated.
C.) Populations within a species must be behaviorally isolated.
D. )Populations within a species must be temporally isolated.

4. Which of the following describes an adaptation? (1 point)
A. an adaptation increases the fitness of the individual
B. an adaptation decreases the fitness of the individual
C. an adaptation does not affect the fitness of an individual
D. an adaptation results from genetic drift

5. What does each node on a cladogram represent? (1 point)
A. the point at which a derived character appeared
B. the point at which a new clade begins
C. the point at which two groups shared a common ancestor
D. the point at which two groups no longer look like each other

6. Which of the following is not an observation that was made by Darwin? (1 point)
A. different animals living in similar environments often had similar characteristics
B. closely related animals living in different environments often had different features
C. fossilized, ancient creatures sometimes had similar features to living creatures
D. all living things share a universal genetic code

7. What is the principle of common descent? (1 point)
A. The principle of common descent is the idea that all living and extinct organisms shared a common ancestor at some point in their evolutionary history.
B. The principle of common descent is the idea that organisms that evolve in the same environment will have the same characteristics.
C. The principle of common descent is the idea that the fittest members of a population will survive and produce more offspring.
D. The principle of common descent is the idea that organisms evolve at a slow and steady rate.

8. The area in which a population of white and brown mice live has started getting much more snow than it has in the past. If this trend continues, what would you expect to happen to the alleles that code for white and brown fur? (1 point)
A. The allele for brown fur would probably increase as genetic drift works on the population.
B. The allele for white fur would probably increase as genetic drift works on the population .
C. The allele for brown fur would probably increase as natural selection works on the population.
D. The allele for white fur would probably increase as natural selection works on the population.

9. At one time, there were many more cheetahs than there are today. About 10,000 years ago, a change in climate caused all but a relatively small number of cheetahs to go extinct. What type of evolutionary mechanism acted on the remaining cheetahs? (1 point)
A. the founder effect
B. the bottleneck effect
c. genetic equilibrium
D. punctuated equilibrium

10. Two important patterns of macroevolution are (1 point)
RNA world and microfossils.
phylogeny and cladistics.
adaptive radiation and convergent evolution.
geographic and temporal isolation.

Answer 1

1. Natural selection is the process in which organisms who have the ability to survive more in the environment are favored than the other ones. In this type of evolution, the ones who do not adapt well with the environment gradually die off and the one with the best traits are left standing. Among the choices, choice B reflects this explanation.

ANSWER: B.

2. Alleles are forms of a gene which determine the phenotype, or the observable traits, of an organism. Natural selection, on the other hand, is a form of evolution where the organisms with the better phenotype are favored and allowed to survive. Thus, allele controls the phenotype while natural selection works directly on it.

ANSWER: D.

3. Speciation is the process of evolution in which a new species is formed. To obtain this, populations within a species should be reproductively isolated. That is, they should be restricted from mating with each other so that the species is forced to accumulate the genetic differences within different populations and overtime form into a completely different species.

ANSWER: A.

4. As explained earlier, evolution through natural selection favors the organisms who are well adapted to the environment. Thus, it only makes sense to conclude that adaptation increases the fitness of the individual because it allows them to survive longer.

ANSWER: A.

5. A cladogram is a form of diagram which illustrates the relationship of different species. The node in the cladogram is found on the main branch and each one represents a point where two groups shared a common ancestor. While it is true that nodes also represent a new clade, the terminal node or the tip of the cladogram do not form a new one.

ANSWER: C.

6. Charles Darwin is best known for developing the theory of evolution. In this theory, Darwin observed the statements given among the choices EXCEPT for the one in choice D. Darwin only observed physical traits or characteristics and did not delve into the genetic code of organisms.

ANSWER: D.

7. Through the literal meaning of the phrase itself, “common descent” tells us that all organisms descended from one common ancestor. That is, we all shared a common ancestor some time in our evolutionary history. Among the choices, choice A accurately describes this.

ANSWER: A.

8. As the environment where white and brown mice live starts to get more snow, white mice will adapt better to the new environment since their white fur would allow them to camouflage better. Natural selection will act on the population and brown mice will soon decrease in population as the allele for white fur increases.

ANSWER: D.

9. Since most of the cheetahs went extinct during a single generation, they experienced what we call the bottleneck effect. The effect is called as such since the number of species figuratively passed through a bottleneck. For instance, billions of cheetah passing through a barrier (change in climate) only allowed thousands of them to get through.

ANSWER: B.

10. Macroevolution is a term for the event where evolution happens at a bigger scale. Key patterns for this event would be adaptive radiation or when organisms start filling different ecological niches and convergent evolution or the development of similar traits among different organisms as a response to the same environment or niche.

ANSWER: adaptive radiation and convergent evolution