AZSCI Crosscutting: Cause and Effect

Question 1

In a coastal area, the removal of mangrove forests for development leads to increased flooding and erosion during storms. What is the most direct cause-and-effect relationship described?

Accepted Answer

Cause: Removal of mangroves; Effect: Reduced protection from storm surge.

Answer

The mangroves serve as a natural barrier that absorbs the energy of storm surges. The cause is the removal of the mangroves. The direct effect is the loss of this protection, which in turn leads to the secondary effects of increased flooding and erosion.

Question 2

A student observes that their potted plant is wilting. They hypothesize that a lack of water is the cause. To test this, they water the plant and observe that it becomes firm again. This experiment helps to:

Accepted Answer

Strengthen the evidence for a causal link between lack of water and wilting.

Answer

By manipulating a single variable (adding water) and observing the predicted effect (recovery from wilting), the student has provided evidence that supports a cause-and-effect relationship. It moves beyond a simple observation to a test of the proposed cause.

Question 3

Data shows that ice cream sales and the number of shark attacks both increase during the summer. Concluding that eating ice cream causes shark attacks is flawed because:

Accepted Answer

Correlation does not imply causation; a third factor (hot weather) is the likely cause of both.

Answer

This is a classic example of correlation versus causation. Two variables can trend together without one causing the other. A hidden or confounding variable, in this case, hot weather, is the actual cause that leads to both more people swimming (increasing shark encounter risk) and more people eating ice cream.

Question 4

The eruption of a large volcano can release massive amounts of ash and sulfur dioxide into the stratosphere. What is a likely effect on the global climate in the year or two following the eruption?

Accepted Answer

A slight global cooling as the particles block sunlight.

Answer

The cause is the injection of aerosols (fine particles) into the stratosphere. The mechanism is that these particles reflect incoming solar radiation back into space before it can warm the surface. The effect is a temporary cooling of the Earth's average temperature.

Question 5

In the process of natural selection, what is the direct cause of an increase in the frequency of a beneficial trait in a population over many generations?

Accepted Answer

The trait providing a survival or reproductive advantage in a specific environment.

Answer

Natural selection is the mechanism. The cause of a trait becoming more common is that individuals possessing that trait are more successful at surviving and reproducing in their specific environment, thus passing the trait to a greater proportion of the next generation.

(AZSCI) Arizona Science Test Practice Test

(AZSCI) Arizona Science Test Practice Test

AZSCI Crosscutting: Cause and Effect