ASU BIO 182 Exam 2 Questions and
Answers Top-Rated
Head in the Clouds
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.
1. In a population of giraffes, the average length of the neck is under directional
selection. - False
Over many generations, the average length of necks in a giraffe population will
increase indefinitely. - False
The relationship between a giraffe's neck length and its fitness would be better
described by a quadratic equation (y = ax^2 + bx + c) than a linear equation (y = ax
+ b). - True
Natural selection would reduce the variation in neck length in a population of
giraffes. - True
In the absence of mutation, the heritability of neck length in a population of
giraffes would remain the same. - False
, Puddle Ponds
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.
6. During the time that subpopulation lived in puddles, they would have been
considered sympatric. - False
While in separate puddles, genetic drift could cause the evolution of reproductive
isolation in rotifers. - True
When the pond reforms, the rotifers from each puddle could be considered
different evolutionary species. - True
When the pond reforms, the bacteria from each puddle would be considered
different biological species. - False
When the pond reforms, natural selection would favor prezygotic isolating
mechanisms that reinforce any postzygotic isolating mechanisms. - True
Fickle fleas
Answers Top-Rated
Head in the Clouds
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.
1. In a population of giraffes, the average length of the neck is under directional
selection. - False
Over many generations, the average length of necks in a giraffe population will
increase indefinitely. - False
The relationship between a giraffe's neck length and its fitness would be better
described by a quadratic equation (y = ax^2 + bx + c) than a linear equation (y = ax
+ b). - True
Natural selection would reduce the variation in neck length in a population of
giraffes. - True
In the absence of mutation, the heritability of neck length in a population of
giraffes would remain the same. - False
, Puddle Ponds
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.
6. During the time that subpopulation lived in puddles, they would have been
considered sympatric. - False
While in separate puddles, genetic drift could cause the evolution of reproductive
isolation in rotifers. - True
When the pond reforms, the rotifers from each puddle could be considered
different evolutionary species. - True
When the pond reforms, the bacteria from each puddle would be considered
different biological species. - False
When the pond reforms, natural selection would favor prezygotic isolating
mechanisms that reinforce any postzygotic isolating mechanisms. - True
Fickle fleas
