BIO 182 EXAM 2 ASU LATEST 2024 ASU BIO

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BIO 182 EXAM 2 ASU LATEST 2024/ ASU BIO

182 EXAM 2 (GENERAL BIOLOGY II) 200+

REAL EXAM PRACTICE QUESTIONS WITH

CORRECT ANSWERS GRA DED A+/ ASU BIO

182 EXAM 2 PREP (NEW!)

Giraffes are the tallest animals on land. An adult giraffe has a neck that exceeds 2 m in length. This neck enables a giraffe to access food that other animals cannot reach and detect predators from a long distance. Studies have shown that giraffes will browse trees at heights that other herbivores cannot reach. The water and nutrients gained from leaves enhance a giraffe's fitness by increasing survival and

reproduction. However, a long neck comes with a cost: the heart must spend more

energy to pump blood to the brain. If a giraffe's neck were too long, the energy required to circulate blood would exceed the energy gained from eating leaves

• in a population of giraffes the average length of the neck is under directional

selection

• Over many generations the average length of necks in a giraffe population will

increase indefinitley.

• the relationship between a giraffes neck length and its fitness would be better

described by a quadratic equation than a linear equation

• natural selection would reduce the variation in neck length in a population of

giraffes

• In the absence of mutation the heritability of neck length in a population of

giraffes would remain the same.

• false- a very short neck limits feeding but a very long neck increases the energy

needed for circulation

• false- selection against very long necks will occur as the energy required for

circulation exceeds the energy gained by eating leaves on tall trees

• true- the relationship is likely hump-shaped which is better described by a

quadratic equation

• true- stabilizing selection reduced the variance of a trait by favoring intermediate

lengths over extreme lengths 1 / 4

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• false- heritability decreases over generations as natural selection involves some

genotypes reproducing less than others During the summer, a small pond loses water to evaporation. Eventually, this pond becomes a series of puddles separated from one another by at least several meters.Most animals disperse or die as the pond dries, but some microbes still remain in the puddles. Each of these species used to live in the pond as a much larger population, but are now subpopulations that reside in the puddles. Some of the microscopic species with short generations are bacteria, paramecia, and rotifers.All of these species reproduce asexually, except for one species of rotifer that reproduces sexually. The puddles remain separated until the following spring, when abundant rain causes them to expand and form a pond like the one from last year

• during the time that subpopulation lived in puddles they would have been

considered sympatric

• when in separate puddles, genetic drift could cause the evolution of reproductive

isolation in rotifers

• When the pond reforms the rotifers from each puddle could be considered

different evolutionary species

• When the pond reforms the bacteria from each puddle would be considered

different biological species.

• when the pong reforms natural selection would be favor prezygotic isolation

mechanisms that reinforce any ostzygotic isolating mechanisms

• false- population that live in different spaces are considered allopatric not

sympatric

• true- although unlikely for such a short period genetic drift in the small

populations could produce traits that isolate them

• true- they could have evolved by selection and drift in the period of geographic

isolation

• false- bacteria are asexual and thus cannot be biological species.
• true- natural selection reinforces post-zygotic isolation mechanisms with pre-

zygotic ones

In epistasis

• nothing changes from generation to generation. 2 / 4

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• one gene alters the effect of another.
• a portion of a chromosome is deleted.
• a portion of a chromosome is inverted.
• the behavior of two genes is entirely independent - ANSWER-b. one gene alters

the effect of another.

In a simple Mendelian monohybrid cross, true-breeding tall plants are crossed with short plants, and the F1 plants, which are all tall, are allowed to self-pollinate. What fraction of the F2 generation are both tall and heterozygous?

• 1⁄8
• 1⁄4
• 1⁄3
• 2⁄3
• 1⁄2 - ANSWER-e. 1⁄2

The phenotype of an individual

• depends at least in part on the genotype.
• is either homozygous or heterozygous.
• determines the genotype.
• is the genetic constitution of the organism.
• is either monohybrid or dihybrid. - ANSWER-a. depends at least in part on the

genotype.

The ABO blood groups in humans are determined by a multiple-allele system in which IA and IB are codominant and are both dominant to IO. A newborn infant is type A. The mother is type 3 / 4

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• Possible phenotypes of the father are
• A, B, or AB.
• A, B, or O.
• O only.
• A or AB.
• A or O - ANSWER-d. A or AB.

Which statement about an individual that is homozygous for an allele is not true?

• Each of its cells possesses two copies of that allele.
• Each of its gametes contains one copy of that allele.
• It is true-breeding with respect to that allele.
• Its parents were necessarily homozygous for that allele.
• It can pass that allele to its offspring. - ANSWER-d. Its parents were necessarily

homozygous for that allele.

Which statement about a test cross is not true?

• It tests whether an unknown individual is homozygous or heterozygous.
• The test individual is crossed with a homozygous recessive individual.

c. If the test individual is heterozygous, the progeny will have a 1:1 ratio.

d. If the test individual is homozygous, the progeny will have a 3:1 ratio.

• Test cross results are consistent with Mendel's model of inheritance for unlinked

genes - ANSWER-d. If the test individual is homozygous, the progeny will have a

3:1 ratio

Linked genes

• must be immediately adjacent to one another on a chromosome.
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