mastering biology ch. 1-5

Terry's grandfather lived to the age of 88 and smoked more than a pack of cigarettes per day throughout his adult life. When Terry tells you this as a reason why "smoking doesn't really harm people," you reply with which of the following?

"That's anecdotal, not scientific, evidence."

The atomic number of neutral chlorine is 17. When chlorine forms an ionic bond with sodium, it gains an electron. How many electrons does it then have?

18

Approximately what proportion of the carbon dioxide currently being introduced into the atmosphere is as a result of the cutting and burning of forests in the tropics?

25%

Approximately how many years ago did the common ancestor of all living things appear on Earth?

4 billion

Polymers of amino acids form a polypeptide. What is the shape of a polypeptide?

A folded or coiled string of beads

The energy stored in adenosine triphosphate (ATP) drives cellular work by energizing other molecules. For example, an enzyme becomes energized when which of the following events occurs?

A phosphate group is transferred from ATP to the enzyme.

After visiting your best friend on the weekend, you awaken on Monday with small red dots on your arms. When you call your friend to tell her, she suggests the rash may be caused by her new laundry soap you used while visiting. Your friend has formulated which of the following?

A testable scientific hypothesis

In what way is ATP analogous to the coiled spring in a dart gun? Note for those who don't play darts: the gun's spring is compressed until the moment of firing, when it expands and propels the dart forward.

ATP releases energy when its phosphate groups are removed in chemical reactions.

What occurs when ATP phosphorylates another molecule?

ATP transfers a phosphate to the molecule, energizing it.

What does the term complementary mean when it is applied to DNA?

Adenine always pairs with thymine; cytosine always pairs with guanine.

Which of the following molecules provides the energy that maintains concentration gradients across cell membranes?

Adenosine triphosphate

Why is it impossible to prove a scientific hypothesis completely true?:

Alternative hypotheses always exist.

What are essential amino acids?

Amino acids the body cannot synthesize

Which of the following is a true statement regarding antioxidants?

Antioxidants inhibit the effects of free radicals.

Many people believe that detox products, such as detox teas, will help them stay healthy by detoxifying the liver. With one exception, all of the following questions should be answered if this belief is to be supported

Are detoxifying teas grown with organic practices without pesticide?

Which of the following statements about enzyme-substrate relationships is correct?

Binding to an enzyme's active site causes bonds in the substrate to break.

Frank and Tim are brothers. Frank is a scientist trying to find a cure for the common cold, whereas Tim works in an automobile repair shop. At last Sunday's family barbecue, their dad said to them, "You know, you both do the same kind of work." What did he mean?

Both test hypotheses systematically.

Cellular respiration involves the breakdown of food molecules to produce energy in the form of ATP. What other molecule(s) is (are) produced by cellular respiration?

Carbon dioxide and water

What is the role of NADH, the "full taxicab", in cellular respiration?

Carry electrons to their destinations in the electron transport chain

The gold standard for medical research is the double-blind, placebo-controlled randomized experiment. Often, however, researchers must use correlational studies instead. Which of the following types of research study is the best for investigating rare diseases?

Case-control

Which of the following organelles or structures is (are) present in animal cells but not in plant cells?

Centrioles

Which of the listed organelles consists of a series of membranous sacs and contains pigment molecules?

Chloroplasts

Which of the following represents a correct pairing of a term and its definition?

Correlation; "relationship between two variables"

Epidemiologists often gain information from which of the following types of study?

Correlational

Which of the following is an accurate statement of an important difference between covalent and ionic bonds?

Covalent bonds represent shared electrons; ionic bonds represent donated electrons.

Which of the following organelles is not located in the cytoplasm of eukaryotic cells?

DNA

What is the role of enzymes in metabolism?

Decrease the activation energy of chemical reactions

Which of the following is the single biggest contribution an individual can make to decreasing his or her own carbon dioxide production?

Drive an energy-efficient vehicle

Drug A is advertised in Internet advertisements as "clinically proven" to reduce acne. Drug B is advertised in your dermatologist's office as "highly effective for my patients" in treating acne. Drug C is advertised as "effective" on the website of the National Institutes of Health. Which would you select to treat your acne?

Drug C

Substance R is too large to diffuse across the cell membrane or to be transported across by a protein. Molecules of Substance R can, however, cross the membrane and exit the cell. By which of the listed processes do they cross?

Exocytosis

Based on the information in Chapter 1, which of the following factors has consistently been shown to prevent the common cold?

Frequent hand-washing

Which stage(s) of cellular respiration take(s) place in the cytosol?

Glycolysis only

A six-carbon glucose molecule and its components pass through which of the listed stages, and in which order, in the process of cellular respiration?

Glycolysis, citric acid cycle, and electron transport chain

Aerobic cellular respiration occurs in four stages. What is Stage 1 called, and what is its product that enters into Stage 2?

Glycolysis; pyruvic acid

Which of the following is a correct pairing between the commercial process that adds hydrogen atoms to unsaturated fats and one of its products?

Hydrogenation and margarine

Which choice shows the substances that rely on facilitated diffusion to cross the cell membrane

Hydrophilic molecules and charged molecules

Imagine that your diet is high in carbohydrates, with plenty of white flour and sugar. One day, you read about the Nurses' Health Survey. This study has followed 20,000 people for more than 20 years. It has shown that a diet low in refined carbohydrates such as white flour and sugar, but high in vegetable fat and protein, significantly reduces heart disease by as much as 30%. Now that you know this, what will you do to stay healthy, and why?

I will change to the vegetable fat/protein diet because the results are most likely practically significant.

Which of the following statements is an example of deductive reasoning?

If vitamin C prevents colds, then people who take vitamin C should have fewer colds.

Researchers studied the relationship between stress levels and colds. Participants were asked to rate their own stress levels before receiving nasal drops that contained a tiny amount of cold virus. Then they reported whether they developed a cold during the next few days. Participants reported stress levels served as which of the following?

Independent variable

Which of the following is an accurate statement about roughage in the diet?

It consists of complex carbohydrates and provides bulk to feces

The glucose that we consume in food is a rich source of energy, but the products of glucose digestion are carbon dioxide and water, which are low in energy. Where has the energy gone by the time glucose has been broken down into carbon dioxide and water?

It is used to synthesize ATP.

Some molecules, such as glucose, require proteins for transport across the cell membrane. This method does not require energy. Why is this form of transport a type of diffusion?

It relies on concentration gradients

In some cases, researchers receive financial benefits from companies that manufacture drugs being evaluated by the researchers themselves. A study in the New England Journal of Medicine, a highly respected scientific journal, found that 60% of articles in the news media do not mention these financial ties when they report on drug research. Does this finding make you more, or less, confident that you are getting the "straight story" from your local newspaper, and why?

Less confident because there is a possibility of bias.

A polyunsaturated fat contains which of the following?

Many double bonds between carbon atoms

Substance X is more concentrated outside the cell than inside the cell. Substance Z is more concentrated inside the cell than outside the cell. Assume that both substances can pass freely through the cell membrane. Over time, what will happen?

Molecules of X will move inside the cell, and molecules of Z wll move outside the cell until equilibrium is reached.

Which of the following best describes the process of facilitated diffusion across a cell membrane?

Movement of a solute down its concentration gradient with the help of membrane proteins

What is the "driving force" in evolution?

Natural selection

Janna was a participant in a scientific experiment comparing two different deodorant brands. She was assigned to use Brand A for six weeks and then report on its effectiveness. Janna was told that the experiment was "double-blind." What does this mean?

Neither Janna nor the investigator knew which deodorant Janna was using.

Dr. Santos believes that aloe vera cream helps heal wounds; after all, her family has used it for generations. She conducts a study of this effect on patients who visit her dermatology practice. Which type of bias could likely occur, and what kind of placebo-controlled study should she design to avoid it?

Observer bias; double-blind

You want to know whether boys in high school are taller now than they were 50 years ago. You gather height data from 30 boys at the local high school and from physical education records of 30 boys who attended the school 50 years ago. Data shows that the average height of boys in high school now is much greater than it was 50 years ago. However, you report that "It is possible that boys are taller now, but further investigation must be done." What might be the statistical reason that your conclusion is not stated more strongly?

One group had a much higher standard error of the mean than the other.

When placed in solutions with different concentrations of salt, animal cells may change their shape. Which of these processes determines whether the cells expand, shrink, or remain the same shape?

Osmosis

Name the gas that is used in place of carbon dioxide during photorespiration, and name one product of this process.

Oxygen; glycolate

Dr. Cy Ence hypothesizes that playing video games prevents colds. He forms two groups: Group A, which will not play video games, and Group B, which will play video games for 2 hours every evening. All participants will keep track of their colds for three months. Dr. Ence recruits the members of Group A at his gym, and the members of Group B at a local bar. What is wrong with his experiment?

Participants are not randomly assigned to the groups.

Which type of molecule is made of a glycerol molecule attached to two fatty acid chains and a phosphate head group?

Phospholipid

Sodium chloride (table salt) dissolves easily in water. This occurs because of which of the following properties of water?

Polarity

Which of the following macromolecules performs all of the following functions: forms integral part of cell membrane, regulates chemical reactions, forms channels in the cell membrane, and acts as hormones?

Proteins

Which of the following choices lists the major macromolecules found in living things?

Proteins, carbohydrates, lipids, and nucleic acids

Units of a sugar, a phosphate, and a nitrogen-containing base make up which of the following molecules?

RNA and DNA

Which of the following is a correct pairing of an organelle and its function?

Ribosome and protein assembly

Which of the following is an important difference between good science and but not of pseudoscience?

Rigorous testing of alternate hypotheses

What is the important structural difference between rough endoplasmic reticulum (ER) and smooth ER?

Rough ER has ribosomes attached to it; smooth ER does not.

Sam and his brother Luke are "like oil and water." What does this common expression mean, and why?

Sam and Luke don't get along well; oil is hydrophobic

Happy Village has a population of 300 people. A survey of 20 people attending the local dog show demonstrated that 18 of them (90%) wanted a Golden Retriever dressed like Santa Claus in the holiday parade. Which type of error should the mayor make sure has not occurred before looking for the most handsome golden retriever in Happy Village?

Sampling error

The year is 3030, and you, an engineer, are creating an enzyme that will be able to separate the engine from the long line of railroad cars it is pulling. This will come in handy for James Bond, who is still a popular hero. What will your new enzyme be called?

Separationase

Which stage of cellular respiration yields the greatest number of ATP molcules per glucose molecule? What is the name of this stage?

Stage 3; Electron transport

The electron transport chain ends with the movement of H+ ions (protons) across the inner mitochondrial membrane. What is the result of this movement?

Synthesis of ATP from ADP and phosphate

The large Swansea Nasal Overton Town (SNOT) study showed that vitamin E can reduce the number of colds. SNOT involved 21,000 participants who were followed for 5 years. Results showed a statistically significant 3% reduction in the number of colds for participants who received vitamin E tablets. Which of the following is an accurate statement about the SNOT results?

The effect of vitamin E on colds is statistically, but not practically, significant.

Several studies have shown that echinacea tea leads to a statistically significant reduction in the severity of colds. What does this statement mean?

The reduction in cold symptoms probably did not occur by chance.

ATP and DNA are similar in at least one important way. What is that way?

They are nucleotides.

Water is a good solvent, in part, because of its hydrogen bonds. Which of the following statements is true of this type of bond?

They can be intramolecular or intermolecular.

Which of the following statements is correct regarding the metabolism of fats and proteins?

They enter different parts of the same metabolic pathways as glucose.

Which of the following statements is true regarding the nucleotides in DNA?

They form antiparallel strands connected by hydrogen bonds

By which of the following measures can it be said that bacteria are more successful organisms than humans?

They have adapted to more, and more diverse, environments.

What role do vitamins play in the body?

They serve as coenzymes to speed up chemical reactions.

What is one physiological reason that an experienced runner breathes heavily for a while after she intensely worked out?

To supply oxygen to the liver so it can convert lactic acid to pyruvate

Sven has moved to a town near the Arctic Circle, an area that receives relatively little sunlight. Sven eats a very healthy diet. His doctor tells him, however, "Now that you live in this part of the world, you should take a vitamin supplement." Which of the following vitamin supplements should Sven take?

Vitamin D

We eat to gain macronutrients. What substances are included in the term macronutrients?

Water, carbohydrates, fats, and proteins

A protein is to ___________ as a polysaccharide is to ____________.

amino acids; monosaccharides

The ____________ is a measure of the energy used by a person who is awake and is equal to approximately ____________.

basal metabolic rate; 1,680 calories/day

Carbohydrate and protein molecules both contain ___________, however, protein molecules also contain ___________ in addition.

carbon, hydrogen, and oxygen; nitrogen

Organic molecules are molecules that contain ___________, which can form bonds with as many as ___________ other elements

carbon; 4

Which of the following is present in prokaryotes but not in eukaryotes?

cell wall

Table sugar, or sucrose, is a ____________ consisting of __________.

disaccharide; fructose and glucose

A(An) ____________ is made of atoms, the smallest units that have the properties of that _____________. When atoms form covalent bonds, a(an) ____________ is formed.

element; element; molecule

Some people believe that tea made from the leaves of the Echinacea purpurea plant can reduce the symptoms of the common cold. To study this, scientists divided participants into two groups: Group A, which drank the Echinacea purpurea tea, and Group B, which drank tea that was identical to Group A's tea except that it did not contain Echinacea purpurea. Group A is called the _____________.

experimental group

To test a hypothesis, scientists conduct ____________ in which they manipulate a(an) ____________ and observe the effects on a(an) ____________.

experiments; independent variable; dependent variable

Which of the following substances uses facilitated diffusion to cross the cell membrane?

glucose

The black-capped chickadee can maintain its internal body temperature of 107°F (-42°C) even when the air temperature around it is well below zero. This is an example of _____________.

homeostasis

In the phospholipid bilayer of the plasma membrane, the heads of the phospholipids are ___________ and face ___________.

hydrophilic; outward

A controlled experiment is an experiment that ______________.

includes a control group

Which of the listed substances does not contain carbon?

minerals

Cellular respiration takes place in the ____________.

mitochondria

________ are to cells as organs are to the body.

organelles

Anaerobic respiration takes place in the absence of ___________ and leads to the buildup of __________ in the body.

oxygen; lactic acid

A chain of many sugar monomers joined by chemical bonds forms a ____________.

polysaccharide

The synthesis of ATP from ADP and phosphate at the inner mitochondrial membrane ___________.

requires energy

A newspaper article describing recent research concerning cures for the common cold is a(an) ___________ source.

secondary

Yeast converts __________ into ethyl alcohol and __________ in a series of reactions called ___________.

sugars; carbon dioxide; fermentation

The induced fit model of enzyme catalysis states that _____________.

the active site of the enzyme changes shape after substrate binds to it

Fats and proteins are metabolized in ___________, yielding which of the following?

the citric acid cycle; Carbon dioxide, water, and ATP