End of Unit Review

If their environment changes to have only seeds in pinecones, which of the following blue jay populations will most likely survive?

• Populations 1 and 2 will most likely survive.

• Populations 1 and 2 will most likely survive.

•  Only Population 2 will survive because it is the only population with variation.

• All the populations will survive because the blue jays will change the thickness of their beaks if they need to.

4. If their environment changes to have only large rocks, which of the following guppy populations will most likely survive?

• Only Population 2 will survive because it is the only population with variation.

•  All the populations will survive because the guppies will change the size of their spots if they need to.

•  Populations 1 and 2 will most likely survive.

• Populations 2 and 3 will most likely survive.

How did the environment change between time 1 and time 2? How did the population change?

• You cannot tell how the environment changed. With each generation, more snakes passed on the gene for red scales to their offspring.

• There were more trees with red leaves. With each generation, more red snakes survived long enough to pass on the gene for red scales to their offspring.

• There were more trees with red leaves. Red snakes are more likely to survive, so the yellow snakes changed to have red scales.

• There were more trees with red leaves. Red snakes are more likely to survive, so both kinds of snakes passed on the gene for red scales to their offspring.

There were more trees with red leaves. Red snakes are more likely to survive, so both kinds of snakes passed on the gene for red scales to their offspring.

•  Prediction 1 is best. Two hummingbirds with short or medium beaks had a baby with a mutation in its genes for the long-beak trait. Because long-beak hummingbirds are more likely to survive, that baby survived long enough to pass on its mutation, so the long-beak trait became more common over generations.

• Prediction 1 is best. Hummingbirds with long beaks are more likely to survive, so hummingbirds with short and medium beaks began to have offspring with a mutation in its genes for the long-beak trait so that their offspring would have a better chance to survive.

• Prediction 2 is best. A hummingbird could have been born with a mutation in its genes for the long-beak trait and lived for a little while. Because long-break hummingbirds are more likely to die, it would have been more likely to die before it had any offspring, so the final population will only have medium or short beak hummingbirds.

• Prediction 2 is best. A hummingbird could have been born with a mutation in its genes for the long-beak trait, but having a mutation in its genes would have caused it to die when it was born, so the final population will only have medium or short beak hummingbirds.

Which prediction best shows what the population could look like after many generations? What caused it to change?

• Prediction 1 is best. Two seals with thick or medium blubber had a baby with a mutation in its genes for the thin trait. Because thin seals are more likely to survive, that baby survived long enough to pass on its mutation, so the thin trait became more common over generations.

• Prediction 1 is best. Seals with thin blubber are more likely to survive, so seals with thick and medium blubber began to have offspring with a mutation in its genes for the thin trait, so that their offspring would have a better chance to survive.

• Prediction 2 is best. A seal could have been born with a mutation in its genes for the thin trait and lived for a little while, but it would have been more likely to die before it had any offspring, so the final population will only have seals with thick or medium blubber.

• Prediction 2 is best. A seal could have been born with a mutation in its genes for the thin trait, but having a mutation in its genes would have caused it to die when it was born, so the final population will only have seals with thick or medium blubber.

The population of squirrels shown above lives in an environment that has always had black trees. Could there ever have been squirrels with gray fur in this population?

• No squirrels could have been born with the gray trait because none of the adult squirrels had that trait to pass down.

• No squirrels could have been born with the gray trait in the past, but some with that trait could be born in the future if the environment changes to have gray trees.

• A squirrel could have been born with a mutation in its genes for the gray trait and lived for a little while, but it would have been more likely to die before it had any offspring.

• A squirrel could have been born with a mutation in its genes for the gray trait, but having a mutation in its genes would have caused it to die when it was born.

What would happen to the population of moths if the trees in their environment changed color?

• The population of moths with colors matching the new tree color would increase over generations.

• The moths would not be affected by the change in tree color.

• The moths would migrate to a different environment with trees of their original color.

• The moths would immediately change color to match the trees.

If a population of rabbits lives in a snowy environment, which trait would most likely become more common over generations?

• Rabbits with long ears, as they can hear predators better.

• Rabbits with short tails, as they are less likely to be caught by predators.

• Rabbits with brown fur, as they are more visible in the snow.

• Rabbits with white fur, as they are better camouflaged in the snow.

How might a population of fish adapt if their water environment becomes more acidic?

• The fish would immediately die off due to the change in acidity.

• The fish would develop thicker scales to protect against the acidity.

• The fish would migrate to a less acidic environment.

• Fish with genetic traits that tolerate acidity would survive and reproduce more.

An inherited trait that increases an organisms ability to survive and reproduce in its environment is called a(n)

• Allele

• Fitness

• Variation

• Genes

• Adaptation