E Chapter 2 Laws of Nature and The Research Process

What is the first step in the scientific method?

• Ask a question

• Hypothesis

• Conclusion

• Analyze data

A student wants to perform a science experiment about plants. He wants to know if a certain type of soil will make plants grow taller. Each pot will receive a different type of soil, but will get the same type of seed, water amount, and sunlight amount.What is the Independent Variable in this story?

• Amount of sunlight

• How tall the plant will grow

• Amount of water

• Type of material the plant is growing in

What do you measure for results (outcome)?

• Dependent variable

• Hypothesis

• Experimental Group

• Constants

If an animal shelter wants to see if a certain dog food causes a dog to gain weight, which of the following would NOT be a constant?

• Type of dog food given

• Amount of dog good given

• Time of day food is given

• Amount of exercise dog is given

Why is it important to have constants in an experiment?

• To make sure the experiment is fair

• Constants are not needed for experiments.

• To measure the dependent variables all at once

• To test many variables at a time

Anna is in charge of studying how the amount of plant food (fertilizer) affects the height of a plant at a local garden. Which testable statement does she investigate?

• There is no way to test this hypothesis.

• If a plant receives two cups of food per day, then the height of the plant will increase

• If a plant gets different amounts of water and two cups of food per day, the height of the plant will increase

• If a plant receives more sunlight, the height of the plant will decrease

1. Aside from repeating a scientific experiment, what else must a scientist do to increase the accuracy of the results?

• Change the hypothesis

• Share data with other scientists for them to repeat or replicate

• Analyze the data faster

• Keep the data for themselves

How is a hypothesis different from a theory?

• A theory has evidence to back it up and a hypothesis is an educated guess as to what is going to happen.

• They are both the same. They both are guesses as to what happens in the natural world.

• A theory is an opinion about how something works but a hypothesis has scientific evidence to support it.

• A hypothesis is used in science and a theory is used in society.

Waldriana would like to investigate the effect of temperature on the amount of food birds eat.  What should she do first to begin her investigation?

• develop a question 
• conduct background research
• design an experiment
• come up with a theory

Rigoberto writes down his hypothesis that more salt will dissolve in cold water than in warm water.  He adds salt to different temperatures of water and records his observations including the amount of undissolved salt.  He finds that there is more salt dissolved in warm water than cold water.  What should Rigoberto do next to make sure that his conclusion is valid?

• do another investigation with sugar
• repeat his investigation using a different liquid than water
• repeat his investigation to see if his results are the same
• change his results to match his original hypothesis