Bio112 Midterm Questions and Verified Answers/Accurate Solutions| Already Graded A+
Analisa and Mateo, two research anthropologists interested in deciphering the relatedness
between four extinct primates, were studying the similarities and differences among a number
of measurements of the complex structures of the jaw fragments they collected, as well as
making many other morphological contrasts between other fossilized bones from dozens of
collected specimens. In the lab, they noticed the lengths of the bones of the leg, particularly the
femur, tibia, and fibula, were very different in all the specimens, whereas the jaw structures
were nearly identical among the specimens. What should they tentatively conclude based on
this evidence? The four primates likely share a close common ancestor or could potentially
be the same species based upon the jaw measurements.
Which of the following are problematic when the goal is to construct phylogenies that
accurately reflect evolutionary history? polyphyletic and paraphyletic taxa
The common ancestors of birds and mammals were very early (stem) reptiles, which almost
certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals,
however, are alike in having four-chambered hearts (two atria, two ventricles). The four-
chambered hearts of birds and mammals are best described as homoplasies.
Neutral theory proposes that a significant proportion of mutations are not acted upon by
natural selection.
When using a cladistic approach to systematics, which of the following is considered most
important for classification?
Selected derived characters
Which kind of DNA should provide the best molecular clock for determining the evolutionary
relatedness of several species whose common ancestor became extinct billions of years ago?
DNA coding for ribosomal RNA
Please use the following information to answer the questions below.In those parts of equatorial
Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β
hemoglobin alleles in the human gene pool.Again, if this population were in equilibrium, and if
, the sickle-cell allele is recessive, what proportion of the population should be susceptible to
sickle-cell disease under typical conditions? .04
Which process in sexual reproduction results in diversity at the nucleotide level?
chromosome crossover.
The restriction enzymes of bacteria protect the bacteria from successful attack by
bacteriophages, whose genomes can be degraded by the restriction enzymes. The bacterial
genomes are not vulnerable to these restriction enzymes because bacterial DNA is methylated.
This situation selects for bacteriophages whose genomes are also methylated. As new strains of
resistant bacteriophages become more prevalent, this in turn selects for bacteria whose
genomes are not methylated and whose restriction enzymes instead degrade methylated DNA.
The outcome of the conflict between bacteria and bacteriophage at any point in time results
from frequency-dependent selection.
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency
of the allele a is 0.3. What is the frequency of individuals that are homozygous for this allele?
.09
Please use the following information to answer the questions below.In those parts of equatorial
Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β
hemoglobin alleles in the human gene pool.With respect to the sickle-cell allele, what should be
true of the β hemoglobin locus in U.S. populations of African Americans whose ancestors were
from equatorial Africa?
1. The average heterozygosity at this locus should be decreasing over time.
2. There is an increasing heterozygote advantage at this locus.
3. Diploidy is helping to preserve the sickle-cell allele at this locus.
4. Frequency-dependent selection is helping to preserve the sickle-cell allele at this locus. 1
and 3
Please use the following information to answer the questions below.In those parts of equatorial
Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β
hemoglobin alleles in the human gene pool.With respect to the sickle-cell allele, what should be
Analisa and Mateo, two research anthropologists interested in deciphering the relatedness
between four extinct primates, were studying the similarities and differences among a number
of measurements of the complex structures of the jaw fragments they collected, as well as
making many other morphological contrasts between other fossilized bones from dozens of
collected specimens. In the lab, they noticed the lengths of the bones of the leg, particularly the
femur, tibia, and fibula, were very different in all the specimens, whereas the jaw structures
were nearly identical among the specimens. What should they tentatively conclude based on
this evidence? The four primates likely share a close common ancestor or could potentially
be the same species based upon the jaw measurements.
Which of the following are problematic when the goal is to construct phylogenies that
accurately reflect evolutionary history? polyphyletic and paraphyletic taxa
The common ancestors of birds and mammals were very early (stem) reptiles, which almost
certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals,
however, are alike in having four-chambered hearts (two atria, two ventricles). The four-
chambered hearts of birds and mammals are best described as homoplasies.
Neutral theory proposes that a significant proportion of mutations are not acted upon by
natural selection.
When using a cladistic approach to systematics, which of the following is considered most
important for classification?
Selected derived characters
Which kind of DNA should provide the best molecular clock for determining the evolutionary
relatedness of several species whose common ancestor became extinct billions of years ago?
DNA coding for ribosomal RNA
Please use the following information to answer the questions below.In those parts of equatorial
Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β
hemoglobin alleles in the human gene pool.Again, if this population were in equilibrium, and if
, the sickle-cell allele is recessive, what proportion of the population should be susceptible to
sickle-cell disease under typical conditions? .04
Which process in sexual reproduction results in diversity at the nucleotide level?
chromosome crossover.
The restriction enzymes of bacteria protect the bacteria from successful attack by
bacteriophages, whose genomes can be degraded by the restriction enzymes. The bacterial
genomes are not vulnerable to these restriction enzymes because bacterial DNA is methylated.
This situation selects for bacteriophages whose genomes are also methylated. As new strains of
resistant bacteriophages become more prevalent, this in turn selects for bacteria whose
genomes are not methylated and whose restriction enzymes instead degrade methylated DNA.
The outcome of the conflict between bacteria and bacteriophage at any point in time results
from frequency-dependent selection.
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency
of the allele a is 0.3. What is the frequency of individuals that are homozygous for this allele?
.09
Please use the following information to answer the questions below.In those parts of equatorial
Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β
hemoglobin alleles in the human gene pool.With respect to the sickle-cell allele, what should be
true of the β hemoglobin locus in U.S. populations of African Americans whose ancestors were
from equatorial Africa?
1. The average heterozygosity at this locus should be decreasing over time.
2. There is an increasing heterozygote advantage at this locus.
3. Diploidy is helping to preserve the sickle-cell allele at this locus.
4. Frequency-dependent selection is helping to preserve the sickle-cell allele at this locus. 1
and 3
Please use the following information to answer the questions below.In those parts of equatorial
Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β
hemoglobin alleles in the human gene pool.With respect to the sickle-cell allele, what should be
