Question

a. click the checkbox to select \the fossil that would be most useful in determining the relative age for the rocks in these geologic columns.\ and b. click 2 checkboxes to select \2 pieces of evidence that describes why these fossils are most useful in determining the relative ages of the rock layers.\ ☐ ammonite ☐ the fossils appear in a single layer ☐ the fossils appear in each geologic column ☐ the fossils appear in all but one layer ☐ the fossils appear in different types of rock ☐ turritella ☐ brachiopod ☐ nodosaria

Explanation:

To solve this, we analyze the fossil usefulness for relative dating (index fossils) and evidence:

Part A: Most Useful Fossil

Index fossils are widespread (appear in many rock layers/columns) and existed for a short time. From the geologic columns (implied by the layers), Brachiopod (or checking the fossil that appears in each geologic column) – but looking at the options, the fossil that appears in each geologic column (consistent across layers) is key. Wait, the “most useful” fossil for relative age is one that is an index fossil: widespread (appears in each column) and short-lived. So the fossil here that appears in each geologic column (from the layers, likely Brachiopod? Wait, the options for fossils: Ammonite, Turritella, Brachiopod, Nodosaria. Wait, the key: index fossils are used for relative dating, so they must be widespread (appear in each column) and have a short time range. So the fossil that appears in each geologic column (option: “The fossils appear in each geologic column” is evidence, but the fossil itself: looking at the layers, Brachiopod (from the key) – but the checkbox for the fossil: let's re-express.

Part B: Evidence for Usefulness

Evidence 1: “The fossils appear in each geologic column” (widespread, so can correlate layers).
Evidence 2: “The fossils appear in different types of rock” (or “short time range” – but from options, “The fossils appear in each geologic column” (widespread) and “The fossils appear in a single layer” is wrong (single layer = not widespread). Wait, no: index fossils are widespread (many columns) and short-lived (so appear in a single layer? No, short-lived means they exist for a short geologic time, so their fossil is found in a narrow range of layers. Wait, correction: Index fossils have two traits: 1) Widespread (appear in many rock columns/locations) and 2) Short-lived (exist for a brief geologic period, so their fossils are found in a limited number of layers (e.g., a single layer or few).

But from the options:

• “The fossils appear in each geologic column” (widespread – good for correlation).
• “The fossils appear in a single layer” (short-lived – good, as they don't persist long, so their layer is a specific time).

Final Selections:

Part A:

Select the fossil that is an index fossil (appears in each column and short-lived). From the fossil options, likely Brachiopod (but the checkbox for the fossil: if “Brachiopod” is an option, select it. Alternatively, the fossil that appears in each column.

Part B:

Select 2 checkboxes:

1. “The fossils appear in each geologic column” (widespread, allows correlation).
2. “The fossils appear in a single layer” (short-lived, defines a specific time).

Answer:

(Checkbox Selections):

• Part A: Select the fossil (e.g., Brachiopod, if checkbox exists) OR the option for the most useful fossil.
• Part B: Select “The fossils appear in each geologic column” and “The fossils appear in a single layer” (or “The fossils appear in different types of rock” – but more accurate: widespread (each column) and short-lived (single layer)).

(Note: The exact fossil name depends on the layers, but the evidence is “The fossils appear in each geologic column” and “The fossils appear in a single layer” as key evidence for an index fossil’s usefulness.)

Final Checkboxes:

• Part A: [ ] Brachiopod (or the fossil that is most useful, likely Brachiopod from the layers).
• Part B: [ ] The fossils appear in each geologic column; [ ] The fossils appear in a single layer.

(If the fossil options include “Brachiopod” as the most useful, select that for Part A. For Part B, select the two evidence checkboxes as above.)