Answers SY2025-26 - 2002070 MJ Comprehensive Science 2 Sem 1 CRUnit Test

Unit Test Answers

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Bena thinks that dissolving more salt in water causes the mixture’s freezing temperature to change.Which is the best type of scientific investigation for Bena to use to study this?

an experimental investigation, because it can provide the most data

a comparative investigation, because it uses a wide range of variables

an experimental investigation, because it allows for the control of variables

a comparative investigation, because it would take the least amount of time

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Which model best represents a pattern?

Option

Which professional most likely uses X-ray technology?

a food critic

a dentist

a financial analyst

a pharmacist

When an experiment is replicated, how should the results of the two experiments compare?

The results of the first experiment should be less accurate.

The results of the second experiment should be less accurate.

The results of the experiments should be similar.

The results of the experiments should be one hundred percent certain.

The results of a dart game were precise but not accurate. The accepted value of the game was the center of the dartboard.

All of the darts hit the center of the board.

Some of the darts hit the center of the board.

The darts hit the same general area of the board.

The darts hit very different areas of the board.

Nami conducts an investigation on plants. She places a grow light on a timer to give the plants different amounts of light to see if this would affect their growth. Which term describes the amount of light in this investigation?

hypothesis

control

dependent variable

independent variable

Charles is conducting an experiment to test the hypothesis that identical twins throughout the world have different fingerprints.How can Charles best conduct this experiment to avoid limitations?

limit the budget of the experiment

conduct smaller studies over time

expand the scope of the experiment

conduct one large study in a short amount of time

How could a scientist demonstrate ethical behavior?

by using data collected by another scientist and not crediting the scientist

by videotaping participants and obtaining permission after the study

by using participant feedback from a study after obtaining permission

by testing a new drug and not mentioning the side effects

The table shows results of an experiment that was replicated.

They are neither precise nor reproducible.

They are precise but not reproducible.

They are accurate and reproducible.

They are accurate but not reproducible.

Which microscope is the most powerful and can map the atoms on the surface of an object?

a classroom compound microscope

a transmission electron microscope

a scanning electron microscope

a scanning tunneling microscope

Diego conducted an experiment to find out what kind of ball bounces the highest when dropped from a five-foot platform. He used a golf ball, a tennis ball, and a soccer ball. He dropped each ball from the balcony once. Diego recorded his observations after each drop.What can Diego do to best improve the reliability of his results?

drop each ball from the platform three more times

record his observations in more than one unit

write at least two scientific questions after the experiment is complete

share his results with other people who have done similar experiments

Mary is conducting an experiment on how pollution affects plant growth. How can she ensure that her data are reliable?

by repeating trials during an experiment

by keeping the results private

by recording values without units

by making a single observation

Which characteristic should a good scientific question have?

It should lead to a hypothesis that is not testable.

It should have a very broad focus with many variables.

It should repeat a question that the researcher has answered before.

It should be based on observations instead of just imagination.

Which kind of investigations allow for the control of variables?

hypothesis

experimental

descriptive

comparative

Which is caused by distracted drivers and may most likely be reduced by brain-powered cars?

fuel consumption

busy highways

traffic accidents

harmful emissions

Cesar has planted an avocado seed for his science project. After a week, Cesar noticed that the seed did not grow and seemed as though it had dried out. He will have to present the process and results to his science class.What type of observations can Cesar present about why the avocado seed did not grow?

He noticed that the roots and stem did not sprout.

He noticed that his classmate’s avocado seed sprouted with minimal water.

He noticed that his classmate had planted the seed deep inside the soil.

He noticed that he had not read the directions.

A scientist hypothesizes that all trees in warm areas produce flowers before the rainy season begins. Which is a limitation to testing this hypothesis?

Rainy season varies around the world.

Geographical location of warm areas is very large.

Flowers of different trees are different colors.

Sample of trees is restricted to warm areas.

Sheila conducts an investigation to see how the amount of salt dissolved in water affects the density of the water. Which statement best describes the correct plan for her procedure?

The density and the amount of water are controls, and the amount of salt and the type of salt are variables.

The amount of water and the amount of salt are controls, and the type of salt and the density are variables.

The type of salt and the amount of water are controls, and the amount of salt and the density are variables.

The type of salt and the density of water are controls, and the amount of salt and the amount of water are variables.

What is a difference between Newton’s laws of motion and Einstein’s theory of relativity?

Newton’s laws are factual statements, while the theory of relativity is a statement of opinion.

Newton’s laws can predict what happens in the future, but Einstein’s theory of relativity cannot.

Newton’s laws explain the observations he made, while the theory of relativity was based on one of Einstein’s hypotheses.

Newton’s laws cannot be replaced, but Einstein’s theory can with new information.

Which describes reproducibility?

The ability of data to be published.

The ability of data to be duplicated.

The ability of data to be changed.

The ability of data to be invalidated.

Students working on plant extracts want to test the hypothesis.Extracts of Bougainvillea flowers are effective in reducing symptoms of acne in teenage girls.The students are denied permission to conduct such an experiment for ethical reasons. What is the most likely reason for being denied permission?

lack of proper equipment

too much of a time commitment

not enough funding

humans as test subjects

Which example is a pseudoscientific process?

examining how sleep affects the brain

using dreams to predict future events

studying sleepwalking by analyzing sleep patterns

interpreting sleep-wake cycles through brain signals

What is an example of a hypothesis leading to a new experiment?

Upon seeing bacteria under the microscope, scientists theorized that they could be the cause of illness.

Galileo dropped different balls off of the Leaning Tower of Pisa to explain how things with different weights fall at the same speed.

Galileo had the idea that objects of different weight will fall at the same speed. He tested this by dropping different balls off of the Leaning Tower of Pisa.

Upon seeing that bacteria caused illnesses, scientists developed the electron microscope to be able to see viruses.

Why is scientific notation used?

to round numbers to the nearest whole number

to promote reproducibility of data

to increase the validity of data

to express very large or very small numbers

Candace is interested in learning more about colors. Which question about colors could be answered through scientific investigation?

Which color bends the most to make a rainbow?

What color of scented marker has the best smell?

Which flower has the prettiest shade of purple on its petals?

What is the best-looking color on a high-performance sports car?

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