Life Science Exam 1 and 2

An experiment is called double - blind when...

neither the subjects nor the researchers know who is in the experimental and control

Which macromolecule has a sugar-phosphate backbone?

nucleic acid

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

objective.

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

it is considered a scientific theory

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

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

Imagine a newly discovered biological molecule that is mostly hydrophobic in its structure. This new molecule will most likely be classified as a

lipid.

In an ideal experiment, there is a

low standard error.

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

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

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

) 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."

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?

) female subjects over 65 that are given placebos

Sampling error can be reduced by

) increasing the sample size.

Which of the following are found in the nucleus of an atom?

) neutrons and protons

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

) secondary source.

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

) the sample size is large

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

5%

What is the pH of a neutral solution?

7

Why are hypothesis never accepted by scientists?

Alternative hypotheses might provide a better answer to the research question

A scientific theory is...

An explanation supported by a very large amount of experimental evidence

Which of the following hypotheses is testable using scientific methods?

Bees can see ultraviolet light that humans cant

_____ reasoning is used to make predictions based on hypothesis

Deductive

______ reasoning takes the form of "if/then" statements

Deductive

_____ reasoing is used to make hypothesis based on previously established observations

Inductive

A scientific hypothesis has which of the following features?

It is falsifiable

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

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

The germ theory was developed by...

Pasteur and Koch

______ 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

Which of the following is a true statement about experimentation

Some hypotheses cannot be testes by experimentation

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?

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

How do the concentrations of H+ and OH- compare to each other in an acidic solution?

The concentration of H+ is higher.

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

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

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

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

____ is a factor inn an experiemnt that can be manipulated

Variable

Which experimental scenario would likely produce the most trustworthy results?

a double-blind study involving a new heart disease treatment

Bias in an experiment can occur when

a technician known which samples are from the control group

Experimental results with very high statistical significance mean that

a true difference between treatment and control groups likely exists

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

an ecological study.

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

anecdotal

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

anecdotal evidence.

The scientific method is used to...

answer specific questions about the natural world

What is the name of a molecule composed of one or more sugars?

carb

If life on Mars is fundamentally like life on Earth, its macromolecules will be based on which element?

carbon

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

The purpose of double- blind exeriements is to

minimize the effects of human bias on the results

it has been observed that people with relatively high stress lievels get a realtively high number of colds. This is a example of

correlation

What kind of bond holds the atoms of a single water molecule together?

covalent bonds that are polar

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

data

Sampling error refers to the

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

Correlations are less convincing than controlled experimental results because correlations

do not eliminate as many alternative hypotheses as experimental results

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

double- blind procedures

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)

ecological study.

Each of the following is a feature of all known living things EXCEPT

genes made from proteins

Nonliving things include fire, water, and viruses. Many features of living things are also found in nonliving things. Of the following features, which is most likely to be absent in nonliving things?

homeostasis

A molecule that is composed only of chains and rings of hydrogen and carbon is called a

hydrocarbon.

What kind of bond holds two water molecules to each other?

hydrogen bonds

What type of chemical bond connects the complementary strands of a DNA molecule to each other?

hydrogen bonds

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

independent variable

A statistically significant result is one that

is unlikely due to chance

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

it ensures that each group will better represent the population as a while

reason why reseachers are skeptical about using zinc lozenges

other reasons why they might recover faster, like stress

The most trustworthy source of scientific information is

peer-reviewed research publications.

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

placebo

Because the electrons in a water molecule are shared unequally between hydrogen and oxygen, water is said to be

polar.

Deductive reasoning is used to make ____ based on a hypothesis

predictions

The atomic number of an element refers to the number of ________ in one atom of that element.

protons

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

secondary

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

should be tested again.

In statistics, a sample is a

small subgroup of a population

Which term best describes the sugar in a sugar-water solution?

solute

Which term best describes the water in a sugar-water solution?

solvent

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

statistically significant

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

statistics.

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

stress might or might not affect susceptibility to colds

Model organisms are used to test hypotheses..

that are potentially too dangerous to perform on human subjects

Statistical analysis of experimental results determines

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

An experimental result is called statistically significant when

the result is unlikely to be due to chance alone

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

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

In general, what makes one kind of amino acid different from other amino acids?

the side group

An atom will be least likely to form chemical bonds with other atoms when

the valence shell is full of electrons.

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

treates the same as experimental subject but not given the experiment treatment

Which of the following pairs of molecules can be held together by a hydrogen bond?

two polar molecules

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.

very likely

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

washing your hands frequently and effectively