Comprehensive Science Review

A student want to find out if watering a plant twice a day rather than once a day would affect the plant growth.  What is the minimum number of plants required to conduct this experiment in order for it to be a fair test?

• One
• Three
• Seven
• It does not matter

This is the variable in an experiment that changes on purpose? 

• Independent variable
• Control variable
• Dependent variable
• Constant

A scientist performs an experiment and asks other scientists around the world to replicate it.  Why would other scientists most likely try to perform the same experiment?

• To see if weather in various regions would affect the results.
• To see if the experiment would be less expensive. 
• Confirm the results.
• Verify hypothesis is a law.

Sara waters the plants in her greenhouse once each day.  She wants to find out if the plants will grow more leaves if they are watered more often.  She counts the number of leaves on each plant before she starts.  She then continues to water half of each type of plant once daily, but she water the other half of each type twice a day. What is the independent variable? 

• Amount of leaves
• Plant growth
• Greenhouse
• Amount of water

Christy wants to find out if the birds that visit the bird feeders in her backyard would rather build nests in birdhouses or in trees.  She puts a birdhouse next to the feeder containing sunflower seeds and hangs a feeder containing cracked corn from a tree. She observes the birds’ nesting activities over the next two weeks and records her observations.  Which of the following would improve Christy’s investigation?

• Put more food in the bird feeders.
• Set them up closer to each other.
• Use the same kind of food. 
• Set up a 3rd feeder with fruit.

This the variable in the experiment that is being measured? 

• Independent variable
• Control variable
• Dependent variable
• Constant

Jonathan’s science teacher is giving a demonstration to show how a metal reacts with different acids.  He places a small piece of the metal in each of three beakers containing a solution of a different acid.  He adds a piece of the metal to a fourth beaker that contains only water.  What is the purpose of the fourth beaker?

• Ensure hypothesis is correct.
• Provides more data.
• Add an independent variable.
• It is the control & used for comparison.

Why might a scientific theory change after it has reached general acceptance?

• Peer review may find fault.
• Scientist may be jealous.
• New evidence.
• Theory or scientific law can never change.

The process of using the senses to obtain information?

• Dependent variable
• Theory
• Observation
• Hypothesis

A general statement that explains how the natural world behaves under certain conditions, for which no exceptions have been found?

• Theory
• Independent variable
• Scientific Law
• Observation.