Question

case study
a two-way street
pinecones have adapted to crossbills. but will
the crossbills adapt to these new defenses?
now that you have seen how pine trees have
adapted to predation by the crossbills,
examine if the birds have developed any
changes of their own. just as there is more
than one kind of pine cone seed, there are
also different kinds of beaks among the
crossbill population. one of these beaks can
be more successful than the other at getting
past the pine cone’s defenses. take a look at
two beaks found in the crossbill population.
match the bill to the appropriate
description
a dropdown: greater beak depth, less curved beak; smaller beak depth, more curved beak
b dropdown
a crossbill with a larger beak depth with less
curve makes for a more powerful beak to get
past the pine’s thick scales.
what type of crossbill do you
think is better suited to eat the
difficult-to-reach seeds kept
deep in the pine cones?

Explanation:

For the "Match the bill to the appropriate description" part:

Bill A:

• From the description, a crossbill with "Greater beak depth, less curved beak" is more powerful to get past pine's thick scales. If we assume Bill A (from the image, likely the more robust - looking beak) should match this, but wait, the dropdown for A has "Smaller beak depth, more curved beak" highlighted? Wait, no, maybe the image of A and B: Let's re - read. The text says "A crossbill with a larger beak depth with less curve makes for a more powerful beak...". So if Bill A (the first bird image) has a more powerful - looking beak (greater depth, less curve), but the dropdown for A has two options. Wait, maybe the question is about matching:

Let's analyze the two beak types:

1. "Greater beak depth, less curved beak": This beak is more powerful to break through thick pine scales.
2. "Smaller beak depth, more curved beak": This beak might be for different pine cone structures or less - defended seeds.

Assuming the image of A (the first bird) has a beak with greater depth and less curve, and B has smaller depth and more curve (or vice - versa). But the text says "A crossbill with a larger beak depth with less curve...". So for the matching:

• If A is the beak with greater depth and less curve, then A should be matched to "Greater beak depth, less curved beak".
• If B is the other, then B is "Smaller beak depth, more curved beak".

For the "What type of crossbill..." part:

The crossbill with "Greater beak depth, less curved beak" is better suited. Because the text says this type of beak is more powerful to get past the pine's thick scales, which would be needed to reach seeds deep in the pine cones (as the thick scales are a barrier to reach deep seeds).

Matching Answers:

• For A: Greater beak depth, less curved beak
• For B: Smaller beak depth, more curved beak

Best Suited Crossbill:

The crossbill with greater beak depth and less curved beak (the one with the more powerful beak) is better suited to eat the difficult - to - reach seeds deep in the pine cones.

Final Answers:

• Match A: Greater beak depth, less curved beak
• Match B: Smaller beak depth, more curved beak
• Best suited crossbill: The crossbill with greater beak depth and less curved beak.

Answer:

For the "Match the bill to the appropriate description" part:

Bill A:

• From the description, a crossbill with "Greater beak depth, less curved beak" is more powerful to get past pine's thick scales. If we assume Bill A (from the image, likely the more robust - looking beak) should match this, but wait, the dropdown for A has "Smaller beak depth, more curved beak" highlighted? Wait, no, maybe the image of A and B: Let's re - read. The text says "A crossbill with a larger beak depth with less curve makes for a more powerful beak...". So if Bill A (the first bird image) has a more powerful - looking beak (greater depth, less curve), but the dropdown for A has two options. Wait, maybe the question is about matching:

Let's analyze the two beak types:

1. "Greater beak depth, less curved beak": This beak is more powerful to break through thick pine scales.
2. "Smaller beak depth, more curved beak": This beak might be for different pine cone structures or less - defended seeds.

Assuming the image of A (the first bird) has a beak with greater depth and less curve, and B has smaller depth and more curve (or vice - versa). But the text says "A crossbill with a larger beak depth with less curve...". So for the matching:

• If A is the beak with greater depth and less curve, then A should be matched to "Greater beak depth, less curved beak".
• If B is the other, then B is "Smaller beak depth, more curved beak".

For the "What type of crossbill..." part:

The crossbill with "Greater beak depth, less curved beak" is better suited. Because the text says this type of beak is more powerful to get past the pine's thick scales, which would be needed to reach seeds deep in the pine cones (as the thick scales are a barrier to reach deep seeds).

Matching Answers:

• For A: Greater beak depth, less curved beak
• For B: Smaller beak depth, more curved beak

Best Suited Crossbill:

The crossbill with greater beak depth and less curved beak (the one with the more powerful beak) is better suited to eat the difficult - to - reach seeds deep in the pine cones.

Final Answers:

• Match A: Greater beak depth, less curved beak
• Match B: Smaller beak depth, more curved beak
• Best suited crossbill: The crossbill with greater beak depth and less curved beak.