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Table 3 Matched items by surface context contrast

From: Exploring the influence of plant and animal item contexts on student response patterns to natural selection multiple choice items

Animal

Plant

Matched pair 1: fitness

1A. Which characteristic would a biologist find most important in deciding which animals are the “most fit”? The animal

1B. Which characteristic would a biologist find most important in deciding which plants are the “most fit”? The plant

a. that lives the longest

a. with the largest number of seeds that grow into new plants

b. that eats the most food

b. that is the strongest and dominates others in the population

c. with the most number of babies that survive and reproduce

c. that lives the longest

d. that is the strongest and dominates others in the population

d. that has the most leaves

Matched pair 2: origin of trait/genetic mechanism

2A. Within a population of blue jays, there are differences in beak size. What causes these differences?

2B. Within a population of prickly pear cactus plants, there is variation in the number of spines that keep predators from eating them. What causes these variations?

a. Blue jays have lots of different mutations in their genes

a. Random genetic changes within the population lead to differences in the number of spines

b. Random genetic changes within the population lead to differences in beak size

b. Changes in the predators that eat them lead to random mutations that change the number of spines

c. Changes in the food source lead to random mutations that change beak size

c. Cactus plants have lots of different mutations in their genes

d. Beak size is not controlled by genes

d. Genes do not control the number of spines

Matched pair 3: origin of trait/genetic mechanism

3A. Although most skunks are black and white, some are grey and others are light-colored. Where did the variations in fur color within a population of skunk most likely come from?

3B. Although most chili peppers are spicy, some are not so spicy and others are very spicy. Where did the variations in spiciness within a population of chili peppers most likely come from?

a. The skunks needed to change in order to survive, so new colors developed

a. The chili peppers needed to change in order to survive, so more spicy chilies developed

b. The skunks changed their color in response to changes in the environment

b. Changes in DNA that happen by chance led to different levels of spiciness

c. Changes in DNA that happen by chance led to new colors

c. The environment caused mutations in the peppers’ DNA that helped them to survive

d. The environment caused mutations in the skunks’ DNA that helped them to survive

d. The chili peppers changed their spiciness in response to changes in the environment

Matched pair 4: variation

4A. Populations of bighorn sheep are made up of hundreds of individual sheep. These sheep

4B. Populations of yucca plants are made up of hundreds of individual plants. These plants

a. are identical to each other

a. vary in many ways

b. vary in many ways

b. are identical to each other

c. are each unique in every way

c. are each unique in every way