Chapter 1

is a rough recipe for answering questions, but the steps need not be performed in the same order as outlined

the scientific method is _______

Positive Control

A ________ ________ is a group in which a known response is expected.

control group

A ________ __________ establishes a base line for an experiment.

Negative control

A _________ _________ is a group in which no response is expected.

it was not a controlled experiment

A recent commercial advertised for a wristband that claimed to restore health and balance by taking advantage of natural frequencies of your biofield. It supports its claim by showing several people first struggling to balance without the wristband and then balancing fine with the wristband. Why should you be skeptical of the claims made in this ad?

it is a positive control

A researcher is designing an experiment to see if a new drug will lower the blood pressure of rats. He uses a double blind design and in addition to giving some of the rats the new drug, some others are given vasopressin, a hormone that is known to lower blood pressure. Why include vasopressin? See Section 1.4 (Page 8) .

pie chart

A scientist has collected data on the stomach contents of raccoons. He finds that they eat marsh grasses, crayfish, clams, insects, and food items discarded by people. What type of graph would be the best way to show the percentages of each of the components of the raccoons' diet? See Section 1.6 (Page 12) .

theory

A well-substantiated explanation of some aspect the natural world, based on a body of facts that have been repeatedly confirmed through observations and experiments, is referred to as a(n) ________.

theory

A(n) ________ is broader in scope than a hypothesis, is supported by a large body of evidence, and generates many new hypotheses.

controlled experiment

A(n) ___________ ___________ involves running a test multiple times while changing one variable, leaving the others the same.

hypothesis

A(n) ___________ is a proposed explanation for a set of observations. It leads to predictions that can be tested by additional observations or by experiments.

observation, question, hypothesis, experiment, results, conclusion

Drag the steps of the scientific method to their correct locations in the concept map.

independent variable

Hunt and her team designed an experiment to test her hypothesis about the effect of BPA on mice. They administered daily doses of BPA to groups of female mice over three, five, or seven days and then tested these mice for genetic abnormalities that occur during meiosis, the division of chromosomes during egg formation. Dosage of BPA administered is a(n) ___________ ________________.

independent variable

Hunt and her team designed an experiment to test her hypothesis about the effect of BPA on mice. They administered daily doses of BPA to groups of female mice over three, five, or seven days and then tested these mice for genetic abnormalities that occur during meiosis, the division of chromosomes during egg formation. The length of time over which mice were exposed to BPA is a(n) _________ _____________.

dependent variable

Hunt and her team designed an experiment to test her hypothesis about the effect of BPA on mice. They administered daily doses of BPA to groups of female mice over three, five, or seven days and then tested these mice for genetic abnormalities that occur during meiosis, the division of chromosomes during egg formation. The percentage of mice displaying genetic abnormalities is the ___________ ___________.

double-blind

In a ________-_________ experiment, neither the participants nor the researchers know who receives the treatment and who does not.

single-blind

In a ________-_________ experiment, the researchers--but not the participants--know who receives the treatment and who does not, to eliminate subjective bias.

from a sick person sitting next to you

In an airplane, from whom are you most likely to acquire a cold or flu virus?

The bags are added to create an experimental model that would be most similar to an actual plane full of people.

In the mock-up of an airplane cabin, there were heated yellow bags where people would normally sit. Why?

natural

Natural or Manipulative? BPA concentrations in the urine of people with diabetes are compared to BPA concentrations in the urine of people without diabetes.

natural

Natural or Manipulative? Blood concentrations of BPA in college students are compared to their recent consumption of canned food items.

manipulative

Natural or Manipulative? Foraging activity levels are compared in tadpoles exposed to four concentrations of toxic metals in the laboratory.

manipulative

Natural or Manipulative? Growth of corn plants is compared in field plots sprayed with three different dosages of weed killer.

natural

Natural or Manipulative? The deformity rate in baby birds from nests in pesticide-sprayed fields is compared to the deformity rate in birds from nests in unsprayed fields.

natural

Natural or Manipulative? The feeding behavior of fish in streams that receive acidic runoff from strip mines is compared to the feeding behavior of fish in unaffected streams.

manipulative

Natural or Manipulative? Tumor development is compared in mice exposed to five dosages of a known carcinogen in the laboratory.

scientific method

Scientists use a general process known as the __________ ___________to ask and answer questions about nature.

Dependent

The ___________ variable is the factor a scientist observes to see the effect of the change made.

Independent

The one variable that is manipulated by a scientist as a potential cause in an experiment is the ____________ variable.

Controlled

The type of test that changes only one variable at a time in order to isolate the results is known as a __________ experiment.

touching surfaces that sick people have touched

What is the major method of transmission of infectious disease when using public transportation?

Choose a setting where a large number of people consistently spend time, such as an office building. Randomly assign everyone to one of two groups. Ask one group to wash their hands every hour, and ask the other group to avoid washing their hands except when truly necessary. Compare the incidence of infectious disease between the two groups over a period of months or years.

Which of the following would be the best experimental design for a study looking at the effect of hand-washing on the incidence of acquiring an infectious disease?

Follow a very large set of people in order to reduce the effect of socioeconomic status. One group is comprised of people who frequently use public transportation, and the other group never uses public transportation. Compare the incidence of infectious disease between the two groups. Collect data without telling the participants too much about the study, so that they do not alter their normal behaviors.

Which of the following would be the best experimental design for a study looking at the risk of getting an infectious disease from using public transportation?

airplane cabin

Which setting has the shortest time span for air refreshment - in other words, which setting has the most frequent air exchange with fresh air?

Children tend to be more tactile, and may not wash their hands as often as they should.

Why are children more likely to pick up germs in public places?

true

You see a display for a new diet pill in a grocery store. The display includes a stack of color-printed handouts claiming that the average user of the product loses 5 pounds per week while taking the product. The handout is probably not a reliable source of information about the efficacy of the diet pills? See Section 1.5 (Page 10) .