Scientific Thinking

When do scientists use a correlation instead of an actual experiment?

• when it is unethical to do the experiment
• when it is too expensive to do the experiment
• whaen it is too hard to do the experiment
• all of the above

Describe the experimental group.

• The group that stays the same
• the group that gets the treatment
• the group that is in its natural state
• the group that changes

Josie was performing an experiment where she grew the same kind of tomatoes in the same soil and amount of water.  She sat one in the sun and one in a closet for 14 days.  What is the independent variable in Josie's experiment?

• tomatoes
• soil
• sunlight
• water

Which of the following hypotheses is written correctly?

•  If a tennis ball is frozen, it won't bounce as high as one that is not frozen.
• If I heat up a tennis ball it will bounce high.
•  If I freeze a tennis ball, then it will not bounce as high.
• Frozen tennis balls will not bounce as high.

In an experiment, the factor that we measure is called the

• controlled variable
• conclusion
• independent variable
• dependent variable

A scientist hypothesizes the the temperature at which an alligator's egg is incubated will determine whether the alligator will be male or female. The independent variable is

• the gender of the alligator
• the male alligators
• the temperature
• the incubator

A scientist hypothesizes the the temperature at which an alligator's egg is incubated will determine whether the alligator will be male or female. The dependent variable is

• the incubator
• the temperature
• the size of the baby alligators
• the gender of the baby alligators

In which step of the scientific method do we want to use graphs?

• communicate results
• asking questions
• analyze data
• make a hypothesis

A scientist who wants to study the effects of fertilizer on plants sets up an experiment. Plant A gets no fertilizer, Plant B gets 5 mg. of fertilizer each day, and Plant C gets 10mg. of fertilizer each day. Which plant is the control group?

• plant B
• All of them
• Plant C
• Plant A

A conclusion reached on the basis of evidence and reasoning is a/an
..

• conclusion
• theory
• inference
• hypothesis