BIO MODULE 3 EXAM

A mosquito population has a gene with two alleles, M1 and M2. If 70% of the gametes produced in the population carry the M2 allele, and the population is not evolving, what proportion of the offspring mosquitoes will be heterozygous at this gene locus?

0.42

If the half-life of carbon-14 is approximately 5000 years old, then approximately how many years old is a fossil containing 1/8th of today's proportions of carbon-14 to carbon-12?

15,000

Red bottoms, a homozygous recessive condition, make up 36% of the bear population. The rest have 'normal' bottoms. Using this information, calculate the frequency of the homozygous dominant and heterozygous genotypes out of 100 individuals.

16; 48

Fish stocks of many species have decreased over the last several centuries as humans have preferentially harvested the largest and most reproductively successful individuals in the population. Many fish populations now exhibit earlier sexual maturity where younger and smaller individuals are capable of reproducing compared to populations two hundred years ago. In regard to body size at sexual maturity, the situation described above is an example of:

A change in the frequency of an existing allele due to directional selection

Females in a population prefer either full facial hair (full beard) or no facial hair (clean-shaven), but do not like partial facial hair (stubble, goatees, mustaches, etc.). What type of selection does this represent?

Disruptive

Which of the following is a key difference between genetic drift and natural selection?

Drift alters frequencies of alleles at random; selection increases frequencies of alleles associated with higher fitness

Two frog populations exist in the same geographic area. Both populations look very similar physically and breed in shallow water, but they are not observed to interbreed in the wild. One population feeds in static pond shallows, while the other feeds in the shallows of rapidly-moving streams. The males in each population make similar mating calls. What type(s) of reproductive isolation is/are likely in effect in the two populations?

Habitat

A key feature of a species defined by the ecological species concept is:

Niche specialization

Male red deer compete for the largest and best mating territories. Large males with large antlers are better at defending the larger, high-quality territories, and females prefer to mate with large males. What features is most important in assessing fitness in male red deer?

Number of offspring surviving to adulthood

Silver beam fish and Common beam fish are capable of producing hybrid offspring, but the hybrid offspring are sterile. This is an example of:

Postzygotic isolation

Why is RNA a promising candidate for the first hereditary molecule in the origin of life on Earth?

RNA molecules can both carry genetic information and have catalytic activity, so may be able to replicate each other without proteins

Assuming the fundamentals of stratigraphy and a perfect fossil record, if we were to extract a column of rock, which which of the following organisms would be found in the deepest layer?

Single-cell Prokaryotes

In a particular species of bird, song volume is controlled by one gene with 2 alleles. Population A has 250 loud singers, 500 medium singers, and 250 soft singers. Population B has 100 loud singers, 800 medium singers, and 100 soft singers. Medium singers are heterozygous.Assuming expected genotype frequencies given by Hardy-Weinberg equations, which population is in Hardy-Weinberg equilibrium with regard to the singing volume gene? a.A b.B c.Both d.Neither

a.A

Which of the following qualities or processes is NOT associated with living things? a.Adaptations in individuals over their lifetimes b.Cells and genetic information c.Requirement for a source of energy d.Responding to changes in the environment e.Imperfect reproduction

a.Adaptations in individuals over their lifetimes

The process of evolution by natural selection leads to populations which are well-adapted to their environment. However, populations almost always have detrimental alleles within the gene pool. Which of the following is NOT a reason such harmful alleles are present in populations? a.Harmful alleles may be useful in the future, and so they are maintained in the population in anticipation of possible change b.Harmful alleles may not affect fitness, because they affect individuals after those individuals have already reproduced c.Harmful alleles may be beneficial in certain environments or other specific circumstances d.Harmful alleles are created due to mutation with each new generation e.Each of these is a reason harmful alleles are present in populations

a.Harmful alleles may be useful in the future, and so they are maintained in the population in anticipation of possible change

Two populations exist in different geographical locations with very different environmental conditions. Gene flow between these two different populations would: a.Increase the likelihood of the populations diverging into two separate species b.Decrease the adaptation of each population to its local environment c.Alter allele frequencies in the populations due to chance alone d.Decrease the genetic diversity in each population e.All of the above are likely outcomes of gene flow between these populations

b.Decrease the adaptation of each population to its local environment

Which of the following is NOT true of mass extinctions? a.Mass extinctions often open previously-occupied niches and facilitate adaptive radiations b.Mass extinctions typically remove only the species that are least-well adapted c.Mass extinctions occur when species become extinct at a much faster rate than normal d.Mass extinctions have occurred multiple times throughout Earth's history e.None of the above are true of mass extinctions

b.Mass extinctions typically remove only the species that are least-well adapted

5.Which of the following is a biologically accurate statement? a.Vertebrates evolved eyes in order to see b.Once aquatic life invaded land, organisms were forced to evolve mechanisms of support and locomotion in order to survive c.Widespread use of pesticides against mosquitoes results in death of non-resistant individuals; as a result, many mosquito populations are comprised mostly of pesticide-resistant individuals d. Frequent use of antibiotics puts pressure on infectious bacteria to evolve antibiotic resistance; as a result, many bacteria are resistant to widely-used antibiotics e.All of the above are biologically accurate statements

c. Widespread use of pesticides against mosquitoes results in death of non-resistant individuals; as a result, many mosquito populations are comprised mostly of pesticide-resistant individuals

Which of the following is alive? a.Human immunodeficiency virus b.An antibiotic-resistance gene found in bacteria c.A human skin cell d.An infectious protein (prion) responsible for mad cow disease e.None of the above are alive

c.A human skin cell

Which of the following is TRUE of oxygen in early Earth history? a.It was initially created by the photosynthetic activity of chloroplasts in plants b.It was an important requirement for the origin of life c.Its accumulation over time is evidenced by banded iron formations in ancient rock d.It occurred following the appearance of eukaryotes in the fossil record e.None of the above are true

c.Its accumulation over time is evidenced by banded iron formations in ancient rock

Which of the following coincided with the mass extinction of the dinosaurs? a.The Cambrian explosion b.The end of the Permian c.The impact of a large meteor d.Oxygenation of the Earth e.None of these

c.The impact of a large meteor

Although biological evolution, strictly speaking, refers to living organisms composed of cells, on which of these stages in the RNA World hypothesis could evolution by selection operate?

catalytic RNA molecules that synthesize RNA molecules using other RNA strands as a template

Evolution does NOT require: a.Heritable variation in the population b.At least two generations of an organism c.Selection or genetic drift to change allele frequencies d.Differences in reproductive potential e.All of the above are required for evolution

d.Differences in reproductive potential

Which of the following is NOT an assumption of Hardy-Weinberg equilibrium? a.No mutation is occurring b.No natural selection is occurring c.Individuals mate randomly d.Population size is fixed e.No migration

d.Population size is fixed

A phylogenetic tree: a.Is a visual representation of relationships between species b.Represents a hypothesis to describe relationships between species c.Can incorporate both genetic and morphological data d.Includes an ancestor and its descendants e.All of the above

e.All of the above

Which of the following is the correct sequence of these events in the RNA-World hypothesis for the origin of life? I. formation of protocells with self-replicating RNA molecules II. synthesis of organic monomers such as amino acids and nucleotides III. synthesis of organic polymers such as polypeptides and nucleic acids IV. formation of DNA-based genetic systems a.I, II, III, IV b.I, III, II, IV c.III, II, I, IV d.IV, III, I, II e.II, III, I, IV

e.II, III, I, IV

Which of the following statements is correct? a.natural selection increases the likelihood that a favorable mutation will occur b.populations retain mutations in anticipation of future environmental changes c.mutations are induced by environmental changes to promote species adaptation d.all of these are correct statements e.none of the above are correct statements

e.none of the above are correct statements

An isolated population of prairie dogs has longer than average teeth. As a result they can eat more grass with less effort and are better able to survive and reproduce. The mutation(s) that resulted in longer teeth:

happened as a result of chance within the prarie dog population and then lead to longer teeth.

Prokaryotes include bacteria and archaea. Given the tree above, why does the term ʹprokaryoteʹ refer to a paraphyletic group?

it excludes one of the descendants of the common ancestor

Speciation that occurs when a sexually reproducing population is not separated by a geographical barrier is:

sympatric