Log inSign up for FREE
Library

AGHS - Bio - Practice with Identifying the Parts of a Controlled Experiment

Last updated over 5 years ago
16 questions
Refer to the following for questions 1-6:

Experiment 1-Krusty Krabs Breath Mints:

Mr. Krabs created a secret ingredient for a breath mint that he thinks will “cure” the bad breath people get from eating crabby patties at the Krusty Krab. He asked 100 customers with a history of bad breath to try his new breath mint. He had 50 customers (Group A) eat his new breath mint after they finished eating a crabby patty. The other 50 (Group B) also received a breath mint after they finished the sandwich, however, it was just a regular breath mint and did not have the secret ingredient. Both groups were told that they were getting the breath mint that would cure their bad breath. Two hours after eating the crabby patties, 19 customers in Group A and 37 customers in Group B reported having better breath than they normally had after eating crabby patties.
1

In this experiment, which group was the control group and why?

1

In this experiment, what was the independent, or "manipulated," variable?

1

Why is the answer you selected above the independent variable (IV)?

1

In this experiment, what was the dependent variable?

1

Why is the answer you selected above the dependent variable (DV)?

1

What conclusion can be drawn based on the collected data? Remember Group A got the new mint and group B got a regular mint!

Use the following information for questions 7-11:

Experiment 2-Termite-tastic Investigation:

A student investigated whether termites dig more tunnels in the light or in the dark. She thought that termites used the filtered light that passed through the top layers of soil to see and thus would dig more tunnels during the daytime. Ten termite colonies were set up with the same number and type of termites per colony. The same amount of food was given to each colony, and the colonies were in the same temperature. Five of the colonies were exposed to normal room light and five were covered with black construction paper so they did not receive light. Every other day for three weeks the length of the tunnels was measured in millimeters using a string and a ruler. Averages for the light and dark groups for each measured were then computed.
1

What is the independent variable?

1

Which ONE of these is NOT an experimental control?

1

Why is your answer to #8 correct. What is an experimental control?

1

Which type of data was collected in this experiment?

1

My answer to #10 is correct because

Use the following information for questions 12-16

Experiment #3-Louis’ Lawn Trouble:

Louis noticed that his lawn had turned very brown during a drought. He wondered if the discolored grass was caused by the lack of rain or something else in the environment. He hypothesized that if the grass received water it would turn green again. Louis sectioned off his lawn into 10 equal-sized sections with the same type of grass and soil in all sections. None of his lawn was shaded. He allowed 5 random sections to continue to receive no water and watered the remaining 5 sections with 5 liters of hose water each day for 16 days. Every two days he recorded the color of the grass in each section by taking photos. At the end of the 16-day experiment, all 5 sections that were given water were noticeably greener than the areas that received no water—the no water areas actually got more brown than they were at the start of the experiment!
1

In this experiment, what was the dependent variable (DV) and why?

1

What type of data was collected?

1

My answer to #13 is correct because

1

Based on th results of Louis' experiment, what inference can be made?

1

The answer to #15 is correct because