BSC 385 Exam 1 Questions
How does inbreeding depression arise?
Rare recessive alleles become expressed in a homozygous state. Inbreeding is compounded with selection.
Which statement best describes the concept known as the Great Chain of Being?
Species are arranged on a scale from lower to higher forms.
Organisms benefit from having homologous pairs of chromosomes because
a deleterious allele can be masked by the presence of a functional copy.
Tasmanian devils once inhabited most of present-day Australia, but only an isolated population on the island of Tasmania has survived to the present day. Which of the following processes has likely affected Tasmanian devils as a result of this history?
a genetic bottleneck
Which of the following could not be described as a phenotype?
a sequence of nucleotides
The graph below shows the change in allele frequency for a beneficial allele over time (the x axis shows generations). Based on the shape of the curve, this allele is most likely...
a. recessive.
alleles are
found at genetic loci always dominant or recessive
Which of the following was not proposed by Darwin?
genetic drift DNA as the hereditary material
The process of changes arising due to random chance is
genetic drift.
Inbreeding results in a higher frequency of ________ in a population. Inbreeding depression occurs because _______.
homozygosity; deleterious recessive alleles are expressed more often
Which of the following examples illustrates phenotypic plasticity?
Children with access to adequate nutrition can grow taller than children who are malnourished.
Bighorn sheep occupy a range that extends from Canada to Mexico; however, this range is not continuous because the sheep prefer steep rocky cliffs, which are often spatially isolated. This is an example of
population structure
The genome of an organism does not contain which of the following elements?
proteins
Weight, because it can vary among individuals over a range of values, is an example of a
quantitative trait
Which of the following type of mutation cannot be inherited by animals?
somatic mutation
A hypothesis is a
tentative explanation for an observation.
Which of the following is/are sources of genetic variation between gametes?
the exchange of genetic material between chromosomes the nonidentical, paired chromosomes of parents the random mixing of parental copies of chromosomes
In the Hardy-Weinberg equation, p2 is
the frequency of dominant alleles
In the Hardy-Weinberg equation, what does 2pq refer to?
the frequency of heterozygotes in a population
If p = 0.8, what is the frequency of heterozygotes in a population, assuming Hardy-Weinberg equilibrium?
0.32
In a population of ground beetles, a genetic locus that codes for setae on the elytra has two variants: G is dominant and codes for setae on the elytra, and g is recessive and codes for glabrous elytra (no setae). If the frequency of beetles with glabrous elytra is 0.36, what is the frequency of the G allele, assuming the population is in Hardy-Weinberg equilibrium?
0.4
Which of the following could result in a polyphenism?
A combination of alleles on a single gene produces two or more discrete phenotypes in a population.
Which correctly describe(s) a population?
A population occupies a large geographic range. A population occupies a small geographic range. A population is a group of interacting and potentially interbreeding individuals of a species.
Which of the following statements best describes how genetic information stored in DNA is transformed into a product?
Genes are transcribed into mRNA, which is then translated into proteins.
In the context of epidemiology, what does it mean to describe the world as "smaller"?
Humans can travel from continent to continent within hours or days.
Which of the following is/are critical for Darwin's idea of natural selection?
Individuals vary in their traits. Natural resources are limited. Some individual variation is heritable
Why are mutations crucial for evolution?
Mutations are the ultimate source of genetic variation in populations.
Which of the following statements is central to the idea of uniformitarianism?
Natural laws that are observable today also operated in the past. Geological change happens gradually for the most part.
Drawing on your knowledge of evolution, why is treatment and/or vaccination against viruses particularly difficult?
Their high replication rate increases the probability of beneficial mutations, their high mutation rate increases the probability of beneficial mutations, and viral reassortment increases the pathogenicity of viruses.
Which of the following would explain why viruses such as influenza evolve so rapidly?
They have a high replication rate. They have a high mutation rate. They can undergo viral reassortment.
Although the Ester1 allele confers a selective advantage to mosquitoes exposed to DDT on the coast of France, carriers of Ester1 in inland populations are more likely to be caught by spiders and other predators. This is an example of
antagonistic pleiotropy
The fluke of a whale and the fluke of a shark
arose through convergent evolution and are the result of natural selection
From examining the fossil record, scientists have postulated that long-term historic changes in cetacean diversity depended on
changes in the abundance of diatoms, which serve as food for animals that were preyed upon by cetaceans.
Inbreeding
creates deleterious recessive alleles increases homozygosity in population
Traits that are more sensitive to environmental stimuli would have
more phenotypic plasticity.
Which of the following may result in evolutionary change in a population?
natural selection and mutation mutation natural selection genetic drift
In comparison with genetic drift, evolution by natural selection is
nonrandom and adaptive
Which of the following are examples of mobile genetic elements?
transposons plasmids
Mutations can affect an organism's phenotype without altering the protein-coding sequence by influencing
when a protein is made where a protein is made the amount of protein made
