Consider the following scenario:
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?
(1 point)
Responses
leg length
leg length
insect population
insect population
drought
drought
fish population
fish population
Which statement is accurate about variations?(1 point)
Responses
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.
In all cases, variations affect how likely it is that an organism reproduces.
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.
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 that give an advantage are more likely to survive.
Consider the following scenario:
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
new mutation
new mutation
advantageous trait
advantageous trait
inactivated gene
inactivated gene
predominant phenotype
advantageous trait
How did the Industrial Revolution impact the population of peppered moths in Britain? (1 point)
Responses
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 light-colored moths became more common.
The light-colored moths became more common.
The Industrial Revolution caused the proportions of each color morph in the population to become equal.
The dark-colored moths became more common.
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 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.
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 long-tailed squirrels may have increased due to increased food availability.
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
multiple bottleneck events
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 they survived 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 their population has recovered.
They are as likely to survive environmental changes because their population has recovered.
They are more likely to survive environmental changes because of the bottleneck event.
They are more 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 less likely to survive environmental changes because of the bottleneck event.
Facts or data are types of(1 point)
Responses
models.
models.
explanations.
explanations.
reasoning.
reasoning.
evidence.Facts or data are types of(1 point)
Responses
models.
models.
explanations.
explanations.
reasoning.
reasoning.
evidence.
evidence.
What change is observed in a distribution curve for a trait affected by directional selection?(1 point)
Responses
It shifts to the right.
It shifts to the right.
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 either to the right or to the left.
It shifts either to the right or to the left.
It shifts to the right.
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?(1 point)
Responses
Directional; males of intermediate coloring make up a small part of the population.
Directional; males of intermediate coloring make up a small part of the population.
Stabilizing; males of intermediate coloring make up the greatest part of the population.
Stabilizing; males of intermediate coloring make up the greatest part of the population.
Directional; males of intermediate coloring make up the greatest part of the population.
Directional; males of intermediate coloring make up the greatest part of the population.
Disruptive; males of intermediate coloring make up a small part of the population
Directional; males of intermediate coloring make up a small part of the population.
Which action an example of genetic modification (creating GMOs)?(1 point)
Responses
selecting fruit that is fleshy with small seeds and planting those the following season
selecting fruit that is fleshy with small seeds and planting those the following season
raising animals via animal husbandry for food purposes
raising animals via animal husbandry for food purposes
breeding dogs for specific traits like size, coat color, and temperament
breeding dogs for specific traits like size, coat color, and temperament
making crops that are resistant to pesticides and insects
making crops that are resistant to pesticides and insects
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)
in 3 to 4 sentences
One possible explanation is that white fur gives the rats an advantage in their environment, such as better camouflage or increased heat reflection. These factors may increase their survival and reproductive rates, leading to a larger proportion of white-furred rats in the population. Another explanation could be genetic drift, where random chance events cause fluctuations in allele frequencies over time and eventually result in a change to the dominant trait.
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) in 3 to 4 sentences
In my population of birds, I've observed three different varieties with varying traits. One variety has long feathers, while another has short feathers, and the third has feathers of medium length. Additionally, some birds have curved beaks, while others have straight beaks. Finally, some birds have a particular color that helps them blend into their habitat better than others.
Based on my observations, I can conclude that birds with long feathers are better adapted to colder weather because they can insulate the body better. Birds with medium-length feathers are more versatile in different types of weather due to their being able to adjust their heat retention. Curved beaks are better suited to eating seeds or nuts, while straight beaks are better at tearing flesh, enabling those birds to become more efficient predators. Birds with a more camouflaged color have an advantage in avoiding predators. These variations show how diversification within a population enables different bird varieties to better adapt to the environment and improve their odds of survival.
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)
Selective breeding is a process of breeding two organisms of the same species with specific desirable characteristics in order to create offspring with those characteristics. The advantage is that it has been used for centuries, has fewer ethical concerns, and is typically less expensive than genetic modification. However, selective breeding is susceptible to the introduction of hidden traits, which can have negative consequences. For example, excessive inbreeding and the suppression of genetic diversity can result from selective breeding, leading to negative outcomes like decreased immune system function.
On the other hand, genetic modification has the potential to change or add specific genes entirely. The advantage is that it can speed up the selective breeding process, improving the success rate while bypassing hidden negative traits. The disadvantage is that genetic modification is a newer technology and can cost more money, and has been the subject of controversy regarding its long-term impact on natural ecosystems. Some may choose to use selective breeding because of its long history and familiarity, while others may choose genetic modification because of its accuracy and precision over selective breeding, which can be time-consuming and unreliable at times. Ultimately, the choice between them depends on the specific needs and goals of the individual or organization using them.
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.
In all cases, variations affect how likely it is that an organism reproduces.
In all cases, variations affect how likely it is that an organism reproduces.
In all cases, variations become more common in a population.
In all cases, variations, , become more common in a population, .
Organisms with variations are less likely to pass these variations to their offspring.
Organisms with variations that give an advantage are more likely to survive.
Natural Selection Unit Test
3 of 143 of 14 Items
Question
Consider the following scenario:
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
predominant phenotype
predominant phenotype
inactivated gene
inactivated gene
advantageous trait
advantageous trait
new mutation
new mutation
advantageous trait
How did the Industrial Revolution impact the population of peppered moths in Britain? (1 point)
Responses
The Industrial Revolution caused the proportions of each color morph in the population to become equal.
The Industrial Revolution caused the proportions of each color morph in the population to become equal.
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 light-colored moths became more common.
The dark-colored moths became more common.
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 increased food availability.
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 a decrease in trees.
The proportion of long-tailed squirrels may have increased due to a decrease 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.
The proportion of short-tailed squirrels may have decreased due to an increase in trees.
The proportion of long-tailed squirrels may have increased due to increased food availability.
Why is the cheetah gene pool small today? (1 point)
Responses
lack of advantageous traits
lack of advantageous traits
poor adaptability
poor adaptability
inbreeding in zoos
inbreeding in zoos
multiple bottleneck events