bio chapter 1

3) Which of the following is an appropriate scientific hypothesis?

D) People catch colds because of exposure to cold temperature.

13) Which of the following hypotheses is testable using scientific methods?

A) Bees can see ultraviolet light that humans can't.

23) Which of the following situations has the greatest potential for observer bias in an experimental process?

A) Dr. Jones is evaluating cancer patients for their responses to a new therapeutic drug. She knows which patients are receiving the placebo and which are receiving the drug.

15) Which of the following statements is the best prediction based on the hypothesis that bird species have decreased in number in a particular wetland because of construction traffic?

A) If a wetland area is disturbed by construction vehicles, then the number of bird species will decrease.

11) Consider this hypothesis: "Drinking Echinacea tea reduces the duration and severity of colds." Which of the following statements is the best prediction based on this hypothesis?

A) If people with a cold drink Echinacea tea, then they will feel better sooner than people who don't consume the tea.

67) What does it mean to say that experimental results are peer reviewed?

A) The results are analyzed by other scientists before they are published.

39) Which experimental scenario would likely produce the most trustworthy results?

A) a double-blind study involving a new heart disease treatment

4) A scientific theory is

A) an explanation supported by a very large amount of experimental evidence.

73) In science, an individual's personal experience or endorsement is considered to be

A) anecdotal evidence.

29) It has been observed that people with relatively high stress levels get a relatively high number of colds. This is an example of a(n)

A) correlation.

44) The incidence of cancer in people living within 100 yards of overhead power lines is recorded. This would be best described as an example of a(n)

A) ecological study.

55) Sampling error can be reduced by

A) increasing the sample size.

40) When graphing data, scientists plot the ________ on the x-axis.

A) independent variable

57) A statistically significant result is one that

A) is unlikely due to chance.

10) When a hypothesis is extensively tested and supported by a large number of studies conducted by many different scientists, then

A) it is considered a scientific theory.

51) A(n) ________ (two words) result is one that is very unlikely to be due to chance differences between the experimental and control groups.

Answer: statistically significant

62) Which of the following is a standard probability that is accepted by most researchers as statistical significance?

B) 5%

12) Which of the following is a testable hypothesis?

B) Avoiding contact with other people reduces the chance of catching a cold.

21) A researcher has hypothesized that the chemical tributyltin (an additive in boat paint) seeps out of the paint into the water and causes reproductive defects in developing marine snails. Which of the following would be a good control in an experiment that tests the effects of tributyltin on developing snails?

B) Developing snails are kept in a tank of water and exposed to boat paint that does not contain tributyltin.

66) Which of the following statements is an example of anecdotal evidence?

B) Dr. Jackson's statement in his infomercial that "I believe my personal cure for bowel disorders is more effective than any drug I've ever prescribed in 20 years of practicing medicine."

14) Which of the following statements is a testable scientific hypothesis?

B) Eating fish reduces the chance of having a stroke.

2) A scientific hypothesis has which of the following features?

B) It is falsifiable.

42) Which of the following is an example of a cohort study?

B) Measure lifetime exposure to coal plant emissions and the incidence of lung cancer in a group of individuals living in a small town.

7) The germ theory was developed by microbiologists, including

B) Pasteur and Koch.

34) Which of the following is a true statement about experimentation?

B) Some hypotheses cannot be tested by experimentation.

6) What hypothesis was tested by Warren and Marshall during their research involving Helicobacter pylori bacteria and stomach ulcers?

B) The cause of many stomach ulcers is the bacterium H. pylori, not spicy food.

37) Bias in an experiment can occur when

B) a technician knows which samples are from the control group.

54) Sampling error refers to the

B) differences between a group of experimental subjects and the population as a whole.

32) Ideally, an experiment studying the effect of a cold medicine should have

B) double-blind procedures.

22) Mehran has heard from some of his teammates that drinking a high protein supplement after football training will improve his muscle mass. He decides to test this hypothesis by comparing the muscle mass of teammates who drink the high protein drink with a control group who drink only water. Which of the following would be the best control for his experiment?

B) randomly selected teammates in training who are given a placebo instead of a protein drink

72) A news report is an example of a(n) ________ source of scientific information.

B) secondary

56) In statistics, a sample is a

B) small subgroup of a population.

28) Model organisms are used to test hypotheses

B) that are potentially too dangerous to perform on human subjects.

63) Statistical analysis of experimental results determines

B) the likelihood that the results are due to the experimental treatment.

47) Scientists are often hesitant to believe the results of a single experiment testing a particular treatment, even when the results are peer reviewed and statistically significant. This is because

B) the results may not be true for humans if the experiment used a model organism.

58) If the two means differ greatly between control and treatment groups, the difference is very likely to be statistically significant only if

B) the sample size is large.

25) Consider an experiment in which subjects are given a pill to test its effectiveness on reducing the duration of a cold. Which of the following is the best way to treat the control group?

C) Give the control group a pill that does not affect the duration of colds.

45) The study of specific human populations for unusually high levels of a disease is

C) an ecological study.

35) Suppose that a botanist is interested in the effect of light on plants. In an experiment she conducts, 50 individuals of a single species of flowering plant are grown for 60 days under different lengths of artificial daylight. The plant species has flowers that can be either white or pink, depending on the genetics of the parent plants. The amount of water and fertilizer provided to each plant is constant. At the end of the experiment, the size of each leaf of every plant is measured. The dependent variable in this experiment is the

C) leaf's size.

60) In an ideal experiment, there is a

C) low standard error.

31) An experiment is called double-blind when

C) neither the subjects nor the researchers know who is in the experimental and control groups.

46) Double-blind experiments are used so that the results will be more

C) objective.

69) The most trustworthy source of scientific information is

C) peer-reviewed research publications.

5) Deductive reasoning is used to make ________ based on a hypothesis.

C) predictions

68) A news report on CNN that describes recently published research on a new treatment for colds is an example of a(n)

C) secondary source.

8) If an inductively reasoned hypothesis makes sense, based on all available and historical observations, then

C) the hypothesis might be false.

64) An experimental result is called statistically significant when

C) the result is unlikely to be due to chance alone.

61) If the reported confidence interval for a population mean is 95%, then there is a

D) 95% probability that the true mean is in the reported range.

9) Why are hypotheses never accepted by scientists?

D) Alternative hypotheses might provide a better answer to the research question.

36) Why is the random assignment of individuals to experimental and control groups important for an experiment?

D) It ensures that each group will better represent the population as a whole.

41) Imagine that the average annual temperature among geographic regions is plotted on the x-axis of a graph, and the spiciness of local food (ranked on a relative "spiciness" scale) in that region is plotted on the y-axis. If the data conform to a very tight relationship, for example, if the hotness of local food increases as the average annual temperature increases, then what can be concluded?

D) Spiciness of food and annual average temperature are correlated, but the relationship is not the result of causation.

70) Which of the following is a sign that scientific information on a website may be unreliable?

D) The site is set up to allow you to buy the product being described.

16) Certain researchers have published peer-reviewed reports that the use of zinc lozenges reduces the length and severity of cold symptoms. What is one reason why some scientists are still skeptical about the merits of using zinc lozenges during a cold?

D) There may be other reasons why the people taking zinc lozenges recovered faster, such as stress levels or differences in their immune systems.

59) Experimental results with very high statistical significance mean that

D) a true difference between treatment and control groups likely exists.

33) Correlations are less convincing than controlled experimental results because correlations

D) do not eliminate as many alternative hypotheses as experimental results.

38) Which of the following would be a control in an experiment testing the prediction that a certain drug prevents cataracts in females over the age of 65?

D) female subjects over 65 that are given placebos

43) Which of the following is a disadvantage of a correlational experiment?

D) it is only feasible for hypotheses for which an experimental treatment can be applied

27) The purpose of double-blind experiments is to

D) minimize the effects of human bias on the results.

65) Results from one test of a new drug are found to be statistically significant; therefore, the hypothesis

D) should be tested again.

52) The specialized branch of mathematics that is used to compare data is called

D) statistics.

30) There is a strong correlation between stress and susceptibility to colds. This means that

D) stress might or might not affect susceptibility to colds.

26) The most effective control subjects in a test of an experimental treatment are

D) treated the same as experimental subjects but not given the experimental treatment.

24) A ________ is a factor in an experiment that can be manipulated.

D) variable

53) When an experiment has a large sample size, and there is a large difference between the results in the experimental and control groups, it is ________ that the experimental results are statistically significant.

D) very likely

74) According to scientific evidence, what is the best prevention method known for reducing the chance of contracting a common cold?

D) washing your hands frequently and effectively

17) ________ reasoning takes the form of "if/then" statements.

Deductive

18) ________ reasoning is used to make a hypothesis based on previously established observations.

Inductive

71) A personal opinion on the effectiveness of a dietary supplement in preventing colds is an example of ________ evidence.

anecdotal

1) The scientific method is used to

answer specific questions about the natural world.

48) A(n) ________ subject is treated as closely as possible to an experimental subject except that he or she does not get the experimental treatment.

control

50) Scientific information called ________, which are collected from well-designed experiments, should allow researchers to either reject or support a hypothesis.

data

20) ________ reasoning is used to make predictions based on a hypothesis.

deductive

49) A(n) ________ is an intentionally ineffective treatment given to members of a control group in an experiment.

placebo

19) A(n) ________ (two words) is an explanation of a set of related observations based on well-supported hypotheses from a number of different, independent lines of research.

scientific theory