Question

A drought hits the habitat of a semi-aquatic bird population. All ponds dry up, and fish populations decline. There are two groups of birds in the population that differ in leg length and diet. Long-legged birds eat fish, while short-legged birds eat insects. The drought has little effect on insect populations. What is the main selective pressure in this scenario?

A leg length
B insect population
C drought
D fish population

Answer 1

Which statement is accurate about variations?(1 point)
Responses

Organisms with variations that give an advantage are more likely to survive.
Organisms with variations that give an advantage are more likely to survive.

Organisms with variations are less likely to pass these variations to their offspring.
Organisms with variations, , are less likely, , to pass these variations to their offspring.

In all cases, variations become more common in a population.
In all cases, variations, , become more common in a population, .

In all cases, variations affect how likely it is that an organism reproduces.

Answer 2

In a muddy lake environment, some fish have brown scales. Most fish, however, have silver scales. Predators have a harder time seeing the fish with brown scales.

Which term best describes the brown scales?

(1 point)
Responses

inactivated gene
inactivated gene

advantageous trait
advantageous trait

new mutation
new mutation

predominant phenotype

Answer 3

How did the Industrial Revolution impact the population of peppered moths in Britain? (1 point)
Responses

The light-colored moths became more common.
The light-colored moths became more common.

The dark-colored moths became more common.
The dark-colored moths became more common.

The Industrial Revolution caused the proportions of each color morph in the population to become unequal.
The Industrial Revolution caused the proportions of each color morph in the population to become unequal.

The Industrial Revolution caused the proportions of each color morph in the population to become equal.

Answer 4

There are two varieties in a population of squirrels: short tails and long tails. Long-tailed squirrels are better at jumping and balancing in trees. Scientists observe that over the span of 100 years, the proportion of the population with long tails increases from 10% to 60%. Which statement is most likely? (1 point)
Responses

The proportion of long-tailed squirrels may have increased due to a decrease in trees.
The proportion of long-tailed squirrels may have increased due to a decrease in trees.

The proportion of long-tailed squirrels may have increased due to increased food availability.
The proportion of long-tailed squirrels may have increased due to increased food availability.

The proportion of short-tailed squirrels may have decreased due to an increase in trees.
The proportion of short-tailed squirrels may have decreased due to an increase in trees.

The proportion of short-tailed squirrels may have decreased due to decreased food availability.
The proportion of short-tailed squirrels may have decreased due to decreased food availability.

Answer 5

Why is the cheetah gene pool small today? (1 point)
Responses

lack of advantageous traits
lack of advantageous traits

inbreeding in zoos
inbreeding in zoos

poor adaptability
poor adaptability

multiple bottleneck events

Answer 6

After a bottleneck event, the population of rabbits in an area has significantly decreased. A decade later, the population of the rabbits recovers to its original numbers. Which statement is correct about the rabbits? (1 point)
Responses

They are as likely to survive environmental changes because their population has recovered.
They are as likely to survive environmental changes because their population has recovered.

They are less likely to survive environmental changes because of the bottleneck event.
They are less likely to survive environmental changes because of the bottleneck event.

They are as likely to survive environmental changes because they survived the bottleneck event.
They are as likely to survive environmental changes because they survived the bottleneck event.

They are more likely to survive environmental changes because of the bottleneck event.

Answer 7

Facts or data are types of(1 point)
Responses

reasoning.
reasoning.

models.
models.

evidence.
evidence.

explanations.

Answer 8

What change is observed in a distribution curve for a trait affected by directional selection?(1 point)
Responses

It shifts either to the right or to the left.
It shifts either to the right or to the left.

It shifts to the right and to the left.
It shifts to the right and to the left.

It shifts to the left.
It shifts to the left.

It shifts to the right.

Answer 9

Imagine you are a scientist observing rats in the wild. As the rats reproduce, rats born with white fur slowly begin to outnumber rats with black fur. In three to five sentences, provide two or more different explanations of why the rats with white fur might be outnumbering the rats with black fur.(4 points)

Answer 10

Pretend you are a scientist observing three different varieties of a single bird species that are part of the same population. In three to five sentences, describe what genetic variations exist in your population. Then, using reasoning skills and mock evidence from your observations, describe the impact these traits have on the birds’ relationships with their environment and predators.(4 points)

Answer 11

Compare and contrast the advantages and disadvantages of selective breeding versus genetic modification. Why might a person choose to use selective breeding over genetic modification? Why might a person choose to create a GMO over a selectively bred organism? Use three to five sentences to formulate your argument.(4 points)

Answer 12

Pretend you are a scientist observing three different varieties of a single bird species that are part of the same population. In three to five sentences, describe what genetic variations exist in your population. Then, using reasoning skills and mock evidence from your observations, describe the impact these traits have on the birds’ relationships with their environment and predators.(4 points)

Answer 13

In a population of birds, brightly colored males and very dull males survive best. Which type of selection is this, and what is most likely true about the proportion of males of intermediate coloring?

Answer 14

D fish population

Answer 15

Organisms with variations that give an advantage are more likely to survive.

Answer 16

advantageous trait

Answer 17

The Industrial Revolution caused the proportions of each color morph in the population to become unequal.

Answer 18

The proportion of long-tailed squirrels may have increased due to a selective advantage in jumping and balancing in trees.

Answer 19

multiple bottleneck events

Answer 20

They are less likely to survive environmental changes because of the bottleneck event.

Answer 21

evidence.

Answer 22

It shifts to the right.

Answer 23

There can be different explanations as to why the rats with white fur might be outnumbering the rats with black fur. One possibility is that there is a selective advantage to white fur, which is providing better camouflage and protection to the rats against predators in their environment. Another possibility is that the black fur trait is becoming less advantageous due to a changing environment, for example if there is less cover for black rats to hide in and they are more easily spotted by predators. Alternatively, it is possible that there is a random element to the distribution of fur color, and the increasing numbers of white rats is simply due to statistical chance and genetic drift.

Answer 24

In this population of the bird species, there are three different varieties, each with its own set of genetic variations. For example, one variety may have a thicker beak, one may have a brighter coloration on the feathers, and another may have longer legs. These different traits may have different impacts on the birds' relationships with their environment and predators. For instance, the birds with thicker beaks may be better adapted to feed on tough seeds, while those with brighter feathers may be more attractive to potential mates. In terms of predation, the birds with longer legs may be more agile and able to escape from predators more easily. These selective pressures may lead to certain traits becoming more common in the population over time. However, additional research and data would be needed to confirm these hypotheses.

Answer 25

Selective breeding and genetic modification are both techniques used to alter the genetic makeup of organisms, but they come with different advantages and disadvantages. One major advantage of selective breeding is that it can be done without introducing foreign genes into the organism, which can help to avoid potential safety concerns or ethical issues. On the other hand, genetic modification can allow for more precise changes to be made to an organism's genome, which may be more effective in achieving specific desired traits.

A person might choose to use selective breeding over genetic modification if they have a specific characteristic they want to improve in an organism and they already have a population with some of those traits. Selective breeding can be done within a relatively short time frame, with only natural or artificial selection being used to get the desired traits.

A person might choose to create a genetically modified organism (GMO) over a selectively bred organism if the desired trait is not present in the population, or if it would take multiple generations to achieve through selective breeding. For example, if a new organism is needed to produce a specific protein for use in medicine, genetic modification may be the best option for creating a high-yield organism with the necessary genetic sequence. However, genetic modification can also carry risks and uncertainties, which are still being evaluated and discussed by scientists and regulators.

Answer 26

In this population of the bird species, there are three different varieties, each with its own set of genetic variations. For example, one variety may have a thicker beak, one may have a brighter coloration on the feathers, and another may have longer legs. These different traits may have different impacts on the birds' relationships with their environment and predators. For instance, the birds with thicker beaks may be better adapted to feed on tough seeds, while those with brighter feathers may be more attractive to potential mates. In terms of predation, the birds with longer legs may be more agile and able to escape from predators more easily. These selective pressures may lead to certain traits becoming more common in the population over time. However, additional research and data would be needed to confirm these hypotheses.

Answer 27

This is an example of disruptive selection. In disruptive selection, individuals with extreme phenotypes are favored over individuals with intermediate phenotypes. In this scenario, brightly colored males and very dull males have the highest survival rates, while males with intermediate coloring have lower survival rates. Therefore, the proportion of males with intermediate coloring is likely to decrease over time as they are less likely to survive and pass on their genes to the next generation.