Natural Selection Pre-Unit Assessment

There is a kind of snake that can be born with red, yellow, or green skin. Eagles hunt these snakes, but snakes that are the same color as their environment are harder for the eagles to see and catch. A population of snakes once lived in an environment where there was sand and dirt, but no grass. The image above shows what the population looked like before. (See diagram labeled 'Population Before' with yellow and red snakes.) Which snake color would be most likely to survive in this environment?

• Red

• Yellow

• Green

• Blue

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NGSS.MS-LS4-4

The diagrams below show two predictions for what the population could look like after many generations. Which prediction best shows what the population could look like after many generations? What caused it to change?

• Prediction 1 is best. Two yellow or red snakes had a baby with a mutation in its genes for the green-skin trait. Because green snakes are more likely to survive, that baby survived long enough to pass on its mutation, so the green trait became more common over generations.

• Prediction 1 is best. Green snakes are more likely to survive, so yellow and red snakes began to have offspring with mutations in their genes.

Tags

NGSS.MS-LS4-4

NGSS.MS-LS3-1

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 guppies passed on the gene for small spots to their offspring.

• The rocks became smaller. With each generation, more guppies with small spots survived long enough to pass on the gene for small spots to their offspring.

• The rocks became smaller. Guppies with small spots are more likely to survive, so the guppies with large spots changed to have small spots.

• The rocks became smaller. Guppies with small spots are more likely to survive, so both kinds of guppies passed on the gene for small spots to their offspring.

Tags

NGSS.MS-LS4-4

NGSS.MS-LS2-4

NGSS.MS-LS2-1

Having fur the same color as their environment would help foxes catch more squirrels because:

• It makes them harder for squirrels to see.

• It makes them run faster.

• It makes them stronger.

• It makes them louder.

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

• The population remains the same; no change occurred.

• The population changes due to natural selection.

• The population decreases due to lack of resources.

• The population increases due to migration.

Tags

NGSS.MS-LS4-4

NGSS.MS-LS2-4

NGSS.MS-LS2-1

Harbor seals live in northern oceans and have a layer of blubber (fat) that keeps them warm. Seals can have blubber of different thicknesses. Seals with thicker blubber are more likely to stay warm and survive in cold ocean waters. But, in warm ocean waters, thicker blubber can make the seals overheat and die. The diagram below shows a population of seals that live in an area of ocean. At time 1, the population had the same number of seals with thin and thick blubber. At time 2, after many generations, there were many more seals with thick blubber and fewer seals with thin blubber in the population. 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 seals passed on the gene for thick blubber to their offspring.

• The water became colder. Seals with thick blubber are more likely to survive, so the seals with thin blubber changed to have thick blubber.

Tags

NGSS.MS-LS4-4

NGSS.MS-LS2-4

NGSS.MS-LS1-5

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

• The water became warm. As a result, ducks with thin feathers were more likely to survive, so the ducks with thick feathers changed to have thin feathers.

• b

  The water became warm. As a result, ducks with thin feathers were more likely to survive, so both kinds of ducks passed on the gene for thin feathers to their offspring.

• The water became warm. With each generation, more ducks with thin feathers survived long enough to pass on the gene for thin feathers to their offspring.

• You cannot tell how the environment changed. With each generation, more ducks passed on the gene for thin feathers to their offspring.

Tags

NGSS.MS-LS4-4

NGSS.MS-LS2-4

NGSS.MS-LS1-5

Scientists measured the height of the giraffes in two different populations. Which population has the largest number of tall giraffes?

Responses

• The population in Niger has the largest number of tall giraffes.

• The population in Somalia has the largest number of tall giraffes.

• Both populations have the same number of tall giraffes.

• These bar graphs do not show which population has more tall giraffes.

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 guppies passed on the gene for small spots to their offspring.

• The rocks became smaller. With each generation, more guppies with small spots survived long enough to pass on the gene for small spots to their offspring.

• The rocks became smaller. Guppies with small spots are more likely to survive, so the guppies with large spots changed to have small spots.

• The rocks became smaller. Guppies with small spots are more likely to survive, so both kinds of guppies passed on the gene for small spots to their offspring.

Tags

NGSS.MS-LS4-4

NGSS.MS-LS2-4

NGSS.MS-LS1-5

The change over time in populations of related species.

• evolution

• transition

• variation

• adaptation

Tags

NGSS.MS-LS4-4

NGSS.MS-LS4-2

NGSS.MS-LS4-1