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