Repetition, Repetition, Replication
Experimental Design
The scientific method
The methods of science
Mystery
100
Performing an experiment multiple times in the same conditions to see if the results are the same
What is repetition?
100
Sue is conducting an experiment. She takes four plants, gives one no water, one 1 cup of water a week, one 2 cups of water a week, and one 3 cups of water a week. She gives each plant the same soil, fertilizer, and sunlight. Sue measures how much each plant's height changes once a week. Her test variable (independent variable) is :
What is the amount of water given to the plant?
100
Ian reads a scientific article every day, demonstrating this step in the scientific method.
What is doing research / gathering information?
100
This branch of science is often studied using computers for modeling, physical models of the solar system, and telescopes to observe things that are far away.
What is astronomy? (Earth space science)
100
Phil was murdered! Forensic investigators perform tests of his hair, skin, and blood to check for DNA. They should complete multiple repetitions for this reason.
What is to show the results are valid?
200
Having a different experimenter perform the same experiment with the same conditions to see if the results are the same.
What is replication?
200
Sue is conducting an experiment. She takes four plants, gives one no water, one 1 cup of water a week, one 2 cups of water a week, and one 3 cups of water a week. She gives each plant the same soil, fertilizer, and sunlight. Sue measures how much each plant's height changes once a week. Her constants are:
What are the soil, the fertilizer, and the sunlight?
200
Isaac thinks, "Why do apples fall down instead of up?" Isaac is doing this step in the scientific method.
What is asking questions?
200
Computers are often used to sort data into neat columns which make it easier to read, called this.
What is a data table?
200
Abby wants to know if her soup is poisoned. She takes poison and measures its pH, then takes the pH of unpoisoned soup. Finally, she measures the pH of her soup. What is the control group in her investigation?
What is the unpoisoned soup?
300
Its purpose is to help show that the results are accurate and valid because one person can get the same results multiple times.
What is repetition?
300
Sue is conducting an experiment. She takes four plants, gives one no water, one 1 cup of water a week, one 2 cups of water a week, and one 3 cups of water a week. She gives each plant the same soil, fertilizer, and sunlight. Sue measures how much each plant's height changes once a week. Her outcome variable (dependent variable) is :
What is the change in the plant's height?
300
Isaac sits under a tree daydreaming. He notices an apple fall. What step in the scientific method is Isaac doing?
What is an observation?
300
This type of graph shows changes over a long period of time for a test (independent) variable that does not fit into distinct categories.
What is a line graph?
300
When Galileo Galilei was alive, most scientists believed that heavy objects fall to Earth faster than light objects. Galileo conducted an experiment and found that objects of the same size and shape fall to Earth at the same speed, no matter their mass. What did Galileo most likely have to do in order to convince other scientists that his observations were correct?
What is repetition. He can perform the experiment in front of people.
400
Its purpose is to help show that the results are accurate and valid because different person can get the same results multiple times.
What is replication?
400
Betsy is testing if bacteria will mutate after being exposed to different substances. Betsy has 12 groups of E-Coli bacteria that will not grow in Agar unless they mutate. She puts 3 in Agar with Laundry detergent A, 3 in Agar with Laundry detergent B, 3 in Agar with Laundry detergent C, and 3 in Agar. Betsy measures the number of bacteria colonies after 1 week. Betsy's control group is this.
What are the bacteria in agar alone?
400
Skylar puts mice on a raised platform after giving them a drug. She measures how much time they spend hiding vs. on the open arms. She then compares these results to the results of mice that were not given a drug before being put on the platform. Skylar is doing this step in the scientific method.
What is a controlled experiment?
400
The change in average global temperature is shown in the chart below. This could be driving that increase.
What is an increase in carbon dioxide in the atmosphere?
400
Lori is testing to see how insects can interact with ecosystems. She counts the number of insects in a wooded area one morning, then the number of insects in an open area in the evening. A problem with this investigation is this.
What is changing multiple things at a time or not doing repetitions?
500
Joseph performs an experiment to test if potatoes grow better sitting on his desk or buried in dirt. He takes two potatoes, cuts each into 8 identical pieces, and buries 8 in dirt while leaving 8 on his desk. The purpose of cutting each potato into 8 is this.
What is repetition to show his results are valid?
500
Betsy is testing if bacteria will mutate after being exposed to different substances. Betsy has 12 groups of E-Coli bacteria that will not grow in Agar unless they mutate. She puts 3 in Agar with Laundry detergent A, 3 in Agar with Laundry detergent B, 3 in Agar with Laundry detergent C, and 3 in Agar. Betsy measures the number of bacteria colonies after 1 week. Betsy's test variable (independent variable) is this.
What is the type of laundry detergent used?
500
CJ performs a test to see if DNA can be isolated from fruit flies using a particular chemical. His result does not match up with those of other scientists. His immediate next step should be this.
What is repeat the experiment several more times to see if he gets the same result?
500
Geologists often analyze rocks to determine how old they are. They use relative dating, where they determine which kind is older, and absolute dating, such as this method shown below. What is this method?
What is radioactive/radiometric dating?
500
A scientist observes six lady beetles of the same species that live in the same location. Each of the lady beetles is a different shade of orange or yellow, and each has a different number of black spots. How do these differences relate to the theory of evolution?
What is These differences show that there is genetic variation in the population that may allow the species to survive changes to its habitat.