Comprehension Check #14

A group of scientists collects samples of rainwater every week and tests the acidity. They then use the rainwater collected to water tomato plants that they grow in their lab. They record the height of the plants each week after the plants are watered, and the results are recorded into the tale below.

The scientists conclude that tap water is the best for tomato plants. However, they decide to ask another group of scientists to do their experiment over.

Why would they want to do this?

• To introduce other scientists as a new variable, since all of the plants grow.

• To show that the experiment can be replicated.

• To make a control group of scientists, to compare the data against.

• To prove that the study can have multiple trials and produce the same results.

A student drops her science notes on the ground, and they become mixed up. She has three pieces of paper that list observations and properties of three samples.

She knows that her notes were organized into three sections by state of matter.

Does the data suggest that any of these pages should be in the same section?

• Yes, the samples all have mass, so they are all solids.

• No, all states of matter have different properties.

• Yes, because Samples 1 and 2 have no color so they must be liquids.

• No, these properties cannot be used to identify the states of matter.

These plants live in the tropical rainforest. If the environment of this area changed so that less rain fell, why would these plants have a hard time surviving?

• The stems would not reach the sunlight.

• The roots would not be able to take in nutrients.

• The large leaves would lose too much water.

• The flowers would have trouble being pollinated.

Turtles are cold blooded, meaning they use the Sun to keep warm. A student hypothesizes that his pet turtle will prefer swimming in warm water. He places his turtle on a rock in the middle of the bathtub, and measures how much time the turtle spends off of the rock during a five minute period. He conducts the experiment under four conditions in the bathtub: no water, warm water, cool water, and room temperature water.

In this experiment, which is the control group?

• The warm water, because it is the student's hypothesis.

• The cool water, because it would be the least expected result.

• The room temperature water, because it is the average water temperature.

• The empty tub, because it shows if the results are random.

A student is studying the migration patterns of several birds. She collects the data in the table.

What conclusion can the student make?

• The distances birds travel is independent of their size.

• Birds more than ten grams in weight are more likely to travel.

• The smallest bird traveled the greatest distance.

• The largest birds stay in the same habitat all year.