Consider the following scenario:
In an aquatic bird population, some birds have long legs. Other birds have short legs. The food supply is minimal. The birds with long legs are able to wade farther into the water where they can find fish. Over time, the birds with long legs become more common.
What scientific term best describes this scenario?
(1 point)
Responses
mutation
mutation
selective pressures
selective pressures
natural selection
natural selection
fitness
fitness
The scientific term that best describes this scenario is natural selection.
Which statement is accurate about variations?
a
In all cases, variations become more common in a population.
b
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.
d
In all cases, variations affect how likely it is that an organism reproduces.
The accurate statement about variations is that organisms with variations that give an advantage are more likely to survive. (Option C is correct)
In an ecosystem, there are two color varieties within a species of toads: brown and green. Over 50 years, the proportion of the population that is green increases from 20% to 50%. Which statement is the most likely to explain this change?
a
A disease caused a decrease in the proportion of brown toads.
b
The environment changed such that green toads can blend into their surroundings better.
c
Pollution caused a decrease in the proportion of brown toads.
d
The environment changed such that toads that can jump higher into the trees to survive better.
The most likely statement to explain this change is that the environment changed such that green toads can blend into their surroundings better. (Option B is correct)
Facts or data are types of
a
evidence.
b
reasoning.
c
models
d
explanations.
Facts or data are types of evidence. (Option A is correct)
Why are the gene pools of small populations reduced compared to those of larger populations?
a
inbreeding
b
lack of advantageous traits
c
lack of suitable mates
d
bottleneck events
Small populations have reduced gene pools because of bottleneck events. (Option D is correct)
In an ecosystem where most flowers are long and bell-shaped, there are two varieties of hummingbird: birds with short beaks and birds with long beaks. What is the most likely hummingbird population composition?
a
only long-beaked hummingbirds
b
more short-beaked hummingbirds
c
more long-beaked hummingbirds
d
only short-beaked hummingbirds