BSCI 160 Midterm: Pre class questions || A+ Score Secured.
Through activities such as starting fires and grazing animals, humans have been responsible for
transforming many ecological systems from... correct answers forests into grasslands.
The advantage of controlled scientific experiments is that correct answers all variables except
one are held constant.
The toe pads of tree frogs and the webbed feet of aquatic frogs are examples of correct answers
structural adaptations.
Evolution is the change in the genetic makeup of correct answers populations of organisms over
time.
Which scenario demonstrates evolution but not adaptation? correct answers A population of rats
that arrived on an island three generations ago has different frequencies of alleles as compared to
the mainland population, due to a bottleneck.
Suppose that individuals in a population of beetles differ in the extent of a dark pigment in their
coloration. Dark-colored beetles are at a higher risk of predation by birds on light-colored soils.
Under what circumstance would the coloration of the beetles most likely remain constant, despite
the differential predation? correct answers The coloration is strictly due to environmental factors.
Which evolutionary process creates new genetic variation? correct answers Mutation
Which is not an example of adaptation? correct answers An individual plant that is better able to
withstand drought after surviving a heat shock
Natural selection can be defined as correct answers the differential survival and reproduction of
individuals.
, Despite the law of independent assortment, when two loci are on the same chromosome, the
phenotypes of the progeny sometimes do not fit the predicted phenotypes. This outcome can be
explained by the phenomenon of correct answers linkage
St. Louis Lad was a Hereford bull born in 1899 and a very popular sire. In 1915, a descendent
calf was born with dwarfism. It was the first of hundreds of cases that would be traced back to
St. Louis Lad as the founder. The dwarf allele is recessive to the normal allele. If you were a
Hereford cattle rancher in 1950, which of the following scenarios would assure you that the bull
you are considering for mating with your cows does not carry the dwarfism gene? correct
answers The bull's offspring from mating with 20 known heterozygous females are unaffected.
Which phase represents the stage at which the two chromosomes have segregated and are in
separate daughter cells? correct answers Anaphase I
**Not the same figure from the assignment, therefore do not think you need to know about the
specifics of Meiosis. Refer to L3 Pre-class to see original, but this figure is the closest I could
find.
Which observed phenotypic pattern in a pedigree would make it more likely that an inherited
trait is recessive rather than dominant? correct answers Some affected individuals have
unaffected parents.
Mendel crossed true-breeding peas of two different characters of seed shape (round or wrinkled)
and color (yellow or green). His results showed that after selfing the F1 plants to obtain F2 seeds,
the round and wrinkled seeds could be either yellow or green. These results were evidence of the
_______ of the alleles of the two characters. correct answers independent assortment
The fact that a trait such as height in humans varies over a wide range of values is due to correct
answers multiple alleles and the environmental influences on the expression of these genes.
An allele is at high frequency in populations of a grass species where rainfall is abundant. It is
less frequent in drier environments. Alleles at most other loci do not vary in frequency with this
Through activities such as starting fires and grazing animals, humans have been responsible for
transforming many ecological systems from... correct answers forests into grasslands.
The advantage of controlled scientific experiments is that correct answers all variables except
one are held constant.
The toe pads of tree frogs and the webbed feet of aquatic frogs are examples of correct answers
structural adaptations.
Evolution is the change in the genetic makeup of correct answers populations of organisms over
time.
Which scenario demonstrates evolution but not adaptation? correct answers A population of rats
that arrived on an island three generations ago has different frequencies of alleles as compared to
the mainland population, due to a bottleneck.
Suppose that individuals in a population of beetles differ in the extent of a dark pigment in their
coloration. Dark-colored beetles are at a higher risk of predation by birds on light-colored soils.
Under what circumstance would the coloration of the beetles most likely remain constant, despite
the differential predation? correct answers The coloration is strictly due to environmental factors.
Which evolutionary process creates new genetic variation? correct answers Mutation
Which is not an example of adaptation? correct answers An individual plant that is better able to
withstand drought after surviving a heat shock
Natural selection can be defined as correct answers the differential survival and reproduction of
individuals.
, Despite the law of independent assortment, when two loci are on the same chromosome, the
phenotypes of the progeny sometimes do not fit the predicted phenotypes. This outcome can be
explained by the phenomenon of correct answers linkage
St. Louis Lad was a Hereford bull born in 1899 and a very popular sire. In 1915, a descendent
calf was born with dwarfism. It was the first of hundreds of cases that would be traced back to
St. Louis Lad as the founder. The dwarf allele is recessive to the normal allele. If you were a
Hereford cattle rancher in 1950, which of the following scenarios would assure you that the bull
you are considering for mating with your cows does not carry the dwarfism gene? correct
answers The bull's offspring from mating with 20 known heterozygous females are unaffected.
Which phase represents the stage at which the two chromosomes have segregated and are in
separate daughter cells? correct answers Anaphase I
**Not the same figure from the assignment, therefore do not think you need to know about the
specifics of Meiosis. Refer to L3 Pre-class to see original, but this figure is the closest I could
find.
Which observed phenotypic pattern in a pedigree would make it more likely that an inherited
trait is recessive rather than dominant? correct answers Some affected individuals have
unaffected parents.
Mendel crossed true-breeding peas of two different characters of seed shape (round or wrinkled)
and color (yellow or green). His results showed that after selfing the F1 plants to obtain F2 seeds,
the round and wrinkled seeds could be either yellow or green. These results were evidence of the
_______ of the alleles of the two characters. correct answers independent assortment
The fact that a trait such as height in humans varies over a wide range of values is due to correct
answers multiple alleles and the environmental influences on the expression of these genes.
An allele is at high frequency in populations of a grass species where rainfall is abundant. It is
less frequent in drier environments. Alleles at most other loci do not vary in frequency with this
