Science quiz

Observe/ Ask a question.

1 step in scientific method

A hypothesis: (a) can be tested (b) is a prediction about the expected outcome of an experiment (c) must be stated in a form that can be either proven or disproven (d) all of the above are true.

D

The part of the experiment in which the experimental factor has been removed is referred to as the

control

1. Which of the following would be done last if one is following the scientific method? (a) forming a hypothesis (b) observing a problem (c) performing an experiment (d) reporting the results.

d

The information gathered from making observations.

data:

The variable observed during the experiment. It is the data collected as a result of changing the independent variable.

dependent variable:

The group that shows the effect of the variable being tested is called the

experimental group

Record and analyze the results.

Fourth step in the scientific method

What is meant by the term "controlled experiment"?

In a "controlled experiment" only one variable is changed at a time. All other variables should be unchanged or "controlled."

The purpose of an experiment is to determine if the ________________ is correct or incorrect.

hypothesis

The variable that is deliberately changed by the scientist.

independent variable:

Why is it important that scientists communicate and report their findings?

In order for the findings to be considered "valid", the experiment must be repeated by other scientists so that the results may be verified and corroborated.

Give two examples of quantitative data.

Number of students who failed a particular test. The amount of weight gain by mice when fed a particular diet.

How many variables should an experiment test at a time?

Only one variable can be tested at a time. If several variables were changed at the same time, the scientist would not know which variable was responsible for the observed results.

Give two examples of qualitative data.

Starch turns purple in the presence of iodine. During mating season, male bird plumage becomes bright and colorful.

A drug company is testing the effectiveness of a new blood pressure medicine using rats as the test subjects. experimental What is the dependent variable?

The observed changes in blood pressure of the test subjects.

true or false. An experiment is a procedure that tests a hypothesis by providing data and observations under controlled conditions.

True

true or false. Science begins with an observation

True.

How is a theory different from a hypothesis?

broad statement of what is believed to be true based on many A hypothesis is an "educated guess" that is testable through observations and experimentation. A theory is a experiments and considerable amounts of data.

A series of steps used by scientists to solve a problem or answer a question.

scientific method:

A drug company is testing the effectiveness of a new blood pressure medicine using rats as the test subjects. What are some possible factors that must remain constant during the testing?

All rats should be kept at the same stress level. All rats should be housed in the same type of cages .All rats should be kept at the same temperature.

Why must experiments be repeated many times?

Experiments are repeated in order to see that the same results are obtained each time. Results cannot be considered "valid" until it is determined that the experiment will always yield the same conclusion.

true or false. In an experiment, the control group is used to test the effect of the independent variable.

False. "experimental" group.

true or false. In scientific investigations, experimenting usually comes before hypothesizing

False: "after".

True or false: A biologist who is measuring the length of salmon as they travel upstream is collecting qualitative data.

False: "quantitative" data.

Draw a conclusion.

Fifth step in the scientific method

Do the final page buy yourself: answer is hi

Hi

Form a hypothesis.

Second step in scientific method

A drug company is testing the effectiveness of a new blood pressure medicine using rats as the test subjects. Describe the control group:

The control group will consist of a set number of rats that will not receive the new blood pressure medicine.

Cell membranes are fragile and can easily be damaged by various substances. HYPOTHESIS When testing the effect of different alcohols on the cell membrane of red beet cells, the damage to the membrane can be measured by the amount of red dye released into the solution. Independent variable: Dependent variable:

The different alcohols being tested. Amount of red dye released as a result of a particular alcohol.

Transpiration is the loss of water from the leaves of plants. The stomata of leaves must open to allow carbon dioxide to enter the leaf for photosynthesis, but when they are open, water vapor escapes into the atmosphere. HYPOTHESIS As the intensity of light is increased, the rate of transpiration will increase, as measured in the lab by the loss of mass of the plant. Independent variable: Dependent variable:

The different light intensities being tested. The mass lost at each light intensity.

Water is the solvent of life, meaning that many substances can easily dissolve in it. HYPOTHESIS Increasing the temperature of a salt water solution will result in a greater amount of salt being dissolved in the solution. Independent variable: Dependent variable:

The different temperatures that are tested. The amount of salt that will dissolve at a particular temperature

7. A drug company is testing the effectiveness of a new blood pressure medicine using rats as the test subjects. Describe the experimental group

The experimental group will consist of a set number of rats that will be given the new blood pressure medicine.

The process of photosynthesis requires a source of carbon dioxide. HYPOTHESIS Increasing the concentration of carbon dioxide available to aquatic plants will increase the rate of photosynthesis, as measured by the number of oxygen bubbles produced. Independent variable: Dependent variable:

The various concentrations of carbon dioxide that are to be tested.The number of oxygen bubbles produced at each concentration of carbon dioxide tested.

Design a controlled experiment.

Third step in the scientific method

A drug company is testing the effectiveness of a new blood pressure medicine using rats as the test subjects. What is the ONE factor that will be different between the experimental group and the control group?

Whether or not the rats receive the new blood pressure medicine.

The factors in an experiment that can be changed are called: (a) variables (b) data (c) the hypothesis (d) the control.

a

Over time, a hypothesis that is supported by many experiments and much data becomes a

theory