A Researcher Discovered a Species of Moth That Lays Its

question 12

Multiple Choice

A researcher discovered a species of moth that lays its eggs on oak trees. Eggs are laid at two distinct times of the year: early in spring when the oak trees are flowering and in midsummer when flowering is past. Caterpillars from eggs that hatch in spring feed on oak flowers and look like oak flowers, but caterpillars that hatch in summer feed on oak leaves and look like oak twigs.
How does the same population of moths produce such different-looking caterpillars on the same trees? To answer this question, the biologist caught many female moths from the same population and collected their eggs then put at least one egg from each female into eight identical cups. The eggs hatched, and at least two larvae from each female were maintained in one of the four temperature and light conditions listed below.
$$\begin{array} { | l | l | } \hline \text { Temperature } & \text { Day length } \\\hline \text { Springlike } & \text { Springlike } \\\hline \text { Springlike } & \text { Summerlike } \\\hline \text { Sumnerlike } & \text { Springlik } \\\hline \text { Summerlike } & \text { Summerlike } \\\hline\end{array}$$
In each of the four environments, one of the caterpillars was fed oak flowers, the other oak leaves. Thus, there was a total of eight treatment groups (4 environments × 2 diets) .
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Recall that in the experiment, caterpillars born in the spring looked like flowers and caterpillars born in the summer looked like twigs. What is the most likely selective advantage for this difference in body shape?

• A) Looking like their food sources allows the caterpillars to move through their environment more efficiently.
• B) Development into the adult moth form is faster for caterpillars shaped like twigs than those shaped like flowers.
• C) Looking like their food source lets the caterpillars blend into their surroundings, reducing predation.
• D) Looking like their food source will increase the caterpillars' feeding efficiency; this would increase their growth rate and survival rate.

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Definitions:

Closed-End Question

A type of question designed to receive a specific, limited response, often "yes" or "no", from a given set of options.

Fixed-Alternative

A type of question format in surveys or questionnaires that presents a limited set of answer options from which respondents must choose.

Dichotomous

Pertaining to something divided or separating into two distinct parts or categories.

Dichotomous

Referring to a division or contrast between two things that are or are represented as being opposed or entirely different.