Where do the minerals come from?" Sanjay asked. "Usually from parent material," his teacher replied. Ms.Winston suggested they set up an experiment to demonstrate where minerals and other soil particles come from. This is their setup.

Question

In this experiment, the brown sugar represents the parent material. What role does water play in soil formation? One choice is NOT correct.
Responses
A The dripping water is mechanically weatherng the parent rock causing pieces to move down the incline.The dripping water is mechanically weatherng the parent rock causing pieces to move down the incline.
B The flowing water causes the parent rock particles to be eroded down hill and collect at the bottom of the tray.The flowing water causes the parent rock particles to be eroded down hill and collect at the bottom of the tray.
C The incline speeds up the erosion of sugar particles, the minerals and soil components, away from the parent material.The incline speeds up the erosion of sugar particles, the minerals and soil components, away from the parent material.
D The dripping water is an is chemically weathering the parent rock causing individual particles to break away from the original mound.The dripping water is an is chemically weathering the parent rock causing individual particles to break away from the original mound.
Question 2
"Let's think about climate differences and our list of soil forming conditions," said Ms. Winston. She told the students to imagine a similar situation taking place in two biomes: a temperate deciduous forest and a tropical rainforest. Using the initial experiment, what differences would you expect based on our list of five conditions of soil formation?
Responses
A There would be little difference in soil formation since both biomes are forests.There would be little difference in soil formation since both biomes are forests.
B There would be more biological activity in the temperature deciduous forest so the parent rock would be broken down faster.There would be more biological activity in the temperature deciduous forest so the parent rock would be broken down faster.
C The increased precipitation in the tropical rainforest would weather parent material at a faster rate but it would also erode faster.The increased precipitation in the tropical rainforest would weather parent material at a faster rate but it would also erode faster.
D The increased temperatures and the increased rain frequency would cause the parent rock to weather more quickly in the tropical rainforest.The increased temperatures and the increased rain frequency would cause the parent rock to weather more quickly in the tropical rainforest.

Answer 1

Let's break down the questions and their responses.

Question 1: The Role of Water in Soil Formation

You are looking for the one choice that is NOT correct regarding the role of water in soil formation via weathering.

• A: "The dripping water is mechanically weathering the parent rock causing pieces to move down the incline."

  • This is true; water can physically break apart rock particles.

• B: "The flowing water causes the parent rock particles to be eroded downhill and collect at the bottom of the tray."

  • This is also true; water can carry particles away through erosion.

• C: "The incline speeds up the erosion of sugar particles, the minerals and soil components, away from the parent material."

  • This statement is true as the incline facilitates the movement of particles.

• D: "The dripping water is chemically weathering the parent rock causing individual particles to break away from the original mound."

  • This is misleading because dripping water primarily causes mechanical weathering. While water can lead to chemical weathering, the description of how it is presented here doesn’t align with the original context of the experiment involving sugar.

Incorrect Response for Question 1: D is the choice that is NOT entirely correct as it misrepresents the primary role of dripping water in this experiment.

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Question 2: Climate Differences and Soil Formation

Now, for the second question about the differences in soil formation between a temperate deciduous forest and a tropical rainforest.

• A: "There would be little difference in soil formation since both biomes are forests."

  • This choice is incorrect as different climates lead to different rates and processes of soil formation.

• B: "There would be more biological activity in the temperature deciduous forest so the parent rock would be broken down faster."

  • This is misleading; tropical rainforests generally have more biological activity due to higher biodiversity.

• C: "The increased precipitation in the tropical rainforest would weather parent material at a faster rate but it would also erode faster."

  • This is a valid observation as high rainfall can increase both weathering and erosion.

• D: "The increased temperatures and the increased rain frequency would cause the parent rock to weather more quickly in the tropical rainforest."

  • This is accurate, as tropical regions typically have higher temperatures and precipitation, affecting weathering rates.

Incorrect Response for Question 2: A is the statement that is NOT correct because it underestimates the significant differences in soil formation processes resulting from the varying climates of the two biomes.

In summary:

• Answer 1: D
• Answer 2: A