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 link and diet. Long-legged birds eat fish, while short-legged birds eat insects. The drought has a little effect on insect populations.
What is the main selective pressure in this scenario?
A. Fish population
B. Leg length
C. Drought
D. Insect population
A. Fish population
Which statement is accurate about variations?
A. In all cases, variations affect how likely it is that an organism reproduces.
B. In all cases, variations become more common in a population.
C. Organisms with variations that give an advantage are more likely to survive.
D. Organisms with variations are less likely to pass these variations to their offspring.
C. 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.
A. Predominant phenotype
B. Inactivated gene
C. New mutation
D. Advantageous trait
D. Advantageous trait
How did the Industrial Revolution impact the population of peppered moths in Britain?
A. The light-colored moths became more common.
B. The dark-colored moths became more common.
C. The Industrial Revolution caused the proportions of each color morph in the population to become equal.
D. The Industrial Revolution caused the proportions of each color morph in the population to become unequal.
B. 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 on 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?
A. The proportion of long-tailed squirrels may have increased due to increased food availability.
B. The proportion of short-tailed squirrels may have decreased due to an increase in trees.
C. The proportion of long-tailed squirrels may have increased due to a decrease in trees.
D. The proportion of short-tailed squirrels may have decreased due to decreased food availability.
A. The proportion of long-tailed squirrels may have increased due to increased food availability.
Why is the cheetah gene pool small today?
A. Multiple bottleneck events
B. Lack if advantageous traits
C. Poor adaptability
D. Inbreeding in zoos