Scientific Method

The analysis of data gathered during a particular experiment is necessary in order to

• formulate a hypothesis for that experiment
• design a control for that experiment
• draw a valid conclusion for that experiment
• develop a research plan for that experiment

A student conducted an original, well-designed experiment, carefully following proper scientific procedure. In order for the conclusions to become generally accepted, the experiment must

• support the original hypothesis
• be conducted by a scientist
• be repeated to verify the reliability of the data
• contain several experimental variables

To test the effect of hormones on plant growth, 6 potted plant seedlings of the same species were measured and then sprayed with auxin (a growth hormone). After 4 weeks of growth under ideal conditions, the plants were measured again. To set up a proper control for this experiment, the investigator should

• spray the samr plants with different amounts of auxin
• wash the auxin off three of the plants after 2 weeks
• grow another 6 seedlings of the same species under the same conditions, spraying them with distilled water only
• spray auxin on 6 plant seedlings of the same species and grow them in the dark for four weeks

In an investigation to determine the change in heart rate with increased activity, students took their pulses immediately before and after exercising for 2 minutes. The data showed an average heart rate of 72 beats per minute before exercising & 90 bpm after exercising. If a valid conclusion is to be made from the results, which assumption must be made?

• In most students, the average heart rate is not affected by exercise
• Each student exercised with the same intensity
• Exercise causes the heart rate to slow down
• The heart rate of each student goes up 18 beats after jogging for 2 minutes

Diagrams, tables, and graphs are used by scientists mainly to

• organize data
• test a hypothesis
• design a research plan for an experiment
• predict the independent variable

A student formulated a hypothesis that cotton will grow larger bolls if magnesium is added to the soil. The student has 2 experimental fields of cotton, one with magnesium and one without. Which data should be collected to support this hypothesis?

• length of the growing season in both fields
• diameter of the cotton bolls in both fields
• height of the cotton plants in both fields
• color of the cotton bolls in both fields

A biologist in a laboratory reports a new discovery based on experimental results. If the experimental results are valid, biologists in other laboratories should be able to

• repeat the same experiment with a different variable and obtain the same results
• repeat the same experiment and obtain the same results
• perform the samr experiment under different experimental conditions and obtain the same results
• perform the same experiment and obtain different results

In an investigation designed to determine the effect of ultraviolet light on mold growth spore, 2 groups of mold spores were grown under identical conditions, except one group was exposed only to ultraviolet light , while the other group was grown in total darkness. The group grown without receiving any ultraviolet light is known as the

• control
• hypothesis
• limiting factor
• dependent variable

A characteristic of all living organisms is that they

• have complex nervous systems
• carry on heterotrophic nutrition
• originate from preexisting life
• require oxygen for respiration

Which life activity is not required for the survival of an individual organism?

• nutrition
• synthesis
• reproduction
• respiration