question

Your baby starts crying. Because she hasn't eaten in 2 hours, you declare, "The baby must be hungry." Based on the scientific method, your statement is a(n) __________.

answer

hypothesis

question

A fundamental characteristic of life on Earth is that __________.

answer

living things grow and reproduce

question

The three natural processes that form the basis for evolution are __________.

answer

genetic variation, inheritance, and natural selection

question

The complexity of living systems __________.

answer

is also highly organized

question

A scientific theory assumes all of the following except __________.

answer

a scientific theory can never be proven wrong

question

Your textbook lists seven characteristics that living organisms possess as a group. However, if you could condense these seven characteristics down to two general descriptive properties exclusive to all living organisms, what would they be?

answer

Macromolecular complexity and multiple levels of organization

question

Which scientist(s) is/are credited with developing the theory of evolution in the mid-1800s?

answer

Both Charles Darwin and Alfred Russel Wallac

question

All of the following characteristics define life except __________.

answer

the ability to do math

question

A group of researchers developed a hypothesis and tested it by designing an experiment. The results of the experiment did not support the original hypothesis. What should the researchers do next?

answer

They should reject the original hypothesis and develop a new hypothesis.

question

Identify a characteristic that is representative of some, but not all, life-forms.

answer

movement over great distances

question

A scientist is testing whether a new cancer drug will work on prostate cancer in humans. To properly interpret results of an experiment, control experiments are needed. Which of the following treatments would serve as a control in these experiments, so that the researchers can conclude that the changes they see in the patients are due to the drug?

answer

Some patients receive a "mock" injection that contains the same solution base and the same volume as the drug but does not actually contain the drug itself.

question

An autotrophic organism __________.

answer

would be one that derives its energy from a renewable external energy source such as sunlight (i.e., photosynthetic organisms)

question

The diversity of life is mainly due to __________.

answer

genetic variation

question

Why is a control needed in an experiment?

answer

To provide a comparison with the experimental results obtained when changing the variable

question

An understanding of basic biological concepts __________.

answer

permits a deeper, and sometimes profound, appreciation of the world around us

question

Experiments are carefully designed in an attempt to __________.

answer

test a single experimental variable

question

Simple experiments generally isolate and test one __________ at a time.

answer

variable

question

A scientist examines an organism and finds that it is eukaryotic, heterotrophic, multicellular, and it absorbs nutrients. She concludes that the organism is most likely a member of the Kingdom __________.

answer

fungi

question

The organic complexity and organization of living organisms depends on the periodic capture of raw materials and energy. Ultimately, the source of this energy is __________.

answer

the sun

question

Which of these experiments would best test the following hypothesis: "Bacteria do not arise spontaneously on meat; they are carried onto meat by droplets of water"?

answer

Place meat in two separate containers: Add droplets of water to one container and no water to the second container. Cover the containers and compare the growth of bacteria in the two containers.

question

Organisms that can make their own food are called __________; organisms that must obtain energy from molecules made by other organisms are called __________.

answer

autotrophs; heterotrophs

question

The process of evolution involves __________.

answer

natural selection of organisms that produce more offspring under certain environmental conditions

question

Natural selection would be best illustrated by which of the following?

answer

A bacterial cell in the human body with a genetic variation that allows it to survive when the person takes antibiotics

question

Which of the following statements is correct?

answer

Mutations are accidental changes in genes.

question

In a famous experiment that helped disprove the possibility of spontaneous generation, Francesco Redi hypothesized that, contrary to popular belief, maggots did not appear spontaneously but came from flies. He predicted that if flies were kept away from meat, then maggots would not appear. To test his hypothesis, Redi placed identical pieces of meat in two identical jars and placed the two jars on the same windowsill. He placed a lid on one jar and left the other uncovered for several days. In the experiment, the control is __________.

answer

the meat in the jar without the lid

question

________ is the study of living things.

answer

biology

question

a(n) _________ consists of all the organisms and their nonliving environment within a given area

answer

ecosystem

question

____________________ is the process of generating hypotheses from a well-supported generalization such as scientific theory

answer

deductive reasoning

question

a plant or other organism that can make its own food is known as a(n) ________. an animal or other organism that cannot make its own food is known as a(n) ________.

answer

autotroph; heterotroph

question

a statement describing an expected observation outcome of a specific experiment is known as a ________.

answer

prediction

question

bacteria are ______, or single-celled, organisms. in contrast, most fungi, plants, and animals are many-celled, or _________.

answer

unicellular; multicellular

question

a(n) __________ cell lacks a nucleus. a(n) ___________ cell has a true membrane-enclosed nucleus

answer

prokaryotic; eukaryotic

question

Which of the following is NOT a characteristic of living things?

answer

creating energy

question

Homeostasis is a living organism's

answer

ability to maintain constant internal conditions even when environmental conditions change.

question

Which of the following can be found in bacteria, but not viruses?

answer

a cell membrane

question

Viruses are

answer

not alive because they are not made of cells and require a host cell for reproduction.

question

Which of the following statements about viruses is FALSE?

answer

The widespread use of antibiotics has led to resistant strains of viruses.

question

Why is combination drug therapy for HIV/AIDS less likely to lead to resistance than single drug therapy?

answer

The likelihood of one virus spontaneously mutating to be resistant to several different drugs at the same time is extremely small.

question

Suppose you were in charge of sending an unmanned space probe to a new planet in search of life. The probe would be able to collect and test samples and make observations, but the planet is too far away for the probe to be able to bring samples back to Earth. The probe is small and would only be able to run a few tests, so you want to pick a test for evidence of life that is broad enough to incorporate all forms of life as we know it. Which one of the following tests would be the best to use in this situation?

answer

a test for the presence of cells that contain DNA

question

An organ, such as the liver, is composed of _____.

answer

tissues

question

Which of these is an organ system?

answer

digestive

question

What are the two main types of cells?

answer

prokaryotes and eukaryotes

question

What is the purpose of a control group in an experiment?

answer

to provide a standard for comparison

question

Which of these is a characteristic of all life?

answer

growing

question

What is the eventual fate of all energy acquired by life?

answer

It becomes heat.

question

A scientist examines an organism and finds that it is eukaryotic, heterotrophic, multi-cellular, and it absorbs food molecules. Which kingdom will she likely place the organism in?

answer

Fungi

question

A 57-year-old woman was admitted to a hospital with an infected toe, and the infection was spreading rapidly. The damage was being caused by an unknown microorganism that could not be cultured in the lab. Doctors observed that antibiotics, which kill only prokaryotes, were ineffective. They suspected that the microbe was a fungus, so they tried the drug Amphotericin, which targets the ergosterols in fungal cells. Because animal cells contain cholesterols, not ergosterols, they are unaffected by the drug. Shortly after receiving Amphotericin, the patient improved, her infection ceased, and she was released from the hospital. In this scenario, what was the hypothesis?

answer

Antibiotics will not kill the microbe because it is a fungal species.

question

Scientific experimentation generally leads to more questions. True or False?

answer

true

question

Which is the correct sequence of increasing organization?

answer

Cell, tissue, organ, organ system

question

Francesco Redi designed an experiment to test the notion of spontaneous generation. He left the first jar of meat open to the air and covered the second jar. The first jar would be called the ________ jar.

answer

control

question

Chromosomes are made of

answer

deoxyribonucleic acid

question

Why do heterotrophs require "food" for survival?

answer

Food provides the organic chemicals needed by heterotrophs.

question

All of the following are true of all living organisms EXCEPT that they

answer

possess either DNA or RNA.

question

Imagine you are waiting backstage for your cue to come onstage when you notice that you are breathing rapidly and beginning to feel light-headed. As you try to control your anxiety and slow your breathing, you think about what you learned in your biology class this week and realize that your hyperventilation is changing your blood pH. Explain.

answer

Rapid breathing increases the pH of your blood, making it more basic.

question

What allows one atom to physically interact with a second atom?

answer

Number of electrons in the outer energy shell

question

Why are hydrophobic molecules such as fats and oils unable to dissolve in watery solutions?

answer

Water molecules form hydrogen bonds with each other, excluding the hydrophobic molecules.

question

When an atom ionizes, what happens?

answer

It gives up or takes up one or more electrons.

question

All elements are __________.

answer

a unique form of matter

question

An atom has two electrons in its inner energy shell, eight in the second, and one in the outermost shell. What is the most likely outcome for this atom in terms of chemical bonding?

answer

The atom will lose its outermost electron, becoming an ion with a charge of +1.

question

The molecule H2SO4 is ionized to H+ ions and SO4- ions in water. Would you predict this to result in a solution that is acidic or basic?

answer

The solution would be acidic, as there would be more H+ than OH- ions.

question

Which of the following is not a subatomic particle?

answer

Ion

question

One solution has a pH of 2 and another has a pH of 3. What would be the relative difference in H+ ion concentration?

answer

A tenfold difference in concentration

question

Oxygen atoms have an atomic number of 8. Neon atoms have 10 electrons. Predict whether or not these atoms are generally reactive with other atoms (i.e., can form chemical bonds with other atoms). Explain your answer.

answer

Oxygen is reactive because its outermost electron shell contains six electrons (is not filled); neon is not reactive because its outermost electron shell contains eight electrons (is filled).

question

Nonpolar covalent bonds are different from polar covalent bonds because __________.

answer

electrons are shared equally in nonpolar covalent bonds and are shared unequally in polar covalent bonds.

question

The atomic number of carbon is 6. A carbon atom has __________ protons and __________ electrons.

answer

six, six

question

The chemical bonding properties of an atom are determined directly by __________.

answer

the outer shell of electrons

question

Isotopes are __________.

answer

atoms with the same number of protons but different numbers of neutrons

question

Which of the following is not true of covalent bonds?

answer

They result when atoms gain or lose one or more electrons.

question

The basic structural units of matter and life are __________.

answer

atoms

question

Atoms are the basic building blocks of elements. Atoms are made up of three different subatomic particles (protons, neutrons, and electrons). Which subatomic particle defines the fundamental nature of each element?

answer

Protons

question

Covalent bonds __________.

answer

share electrons with another atom

question

If electrons in water molecules were equally attracted to the hydrogen and oxygen nuclei, water molecules would be __________.

answer

less polar

question

Why is water essential for life?

answer

Water is a good solvent, water moderates the effects of temperature, and when water freezes, it forms ice that floats.

question

How many covalent bonds can the nitrogen (atomic number = 7) atom form?

answer

Three

question

Imagine that you wanted to make a time capsule in which you would seal important artifacts from your life (pictures, poems, a lock of your baby hair, etc.), to be opened by your heirs 1,000 years from now. To prevent these artifacts from decaying, you want to fill the capsule with a gas that would be least reactive. Which of these gases would you choose: oxygen gas (O2) carbon dioxide (CO2), argon gas (Ar), or hydrogen gas (H2)? (The atomic numbers of the atoms in these molecules are as follows: oxygen = 8; carbon = 6; argon = 18; and hydrogen = 2.)

answer

Argon gas

question

An oxygen atom with eight protons in its nucleus would be expected to have how many electrons?

answer

Eight electrons

question

A hypothetical atom has one electron shell that can hold 10 electrons. This atom has seven protons and is electrically neutral. How many covalent bonds can this atom form?

answer

Three

question

Which of the following lists of terms is in the correct order of size, going from smallest to largest?

answer

Electron, proton, atomic nucleus, atom, molecule

question

What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?

answer

6

question

Which of these refers to atoms with the same atomic number but different atomic masses?

answer

These atoms are isotopes.

question

Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have?

answer

10

question

An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?

answer

5

question

Atoms with the same number of protons but with different electrical charges _____.

answer

are different ions

question

In salt, what is the nature of the bond between sodium and chlorine?

answer

ionic

question

An ionic bond involves _____.

answer

an attraction between ions of opposite charge

question

A(n) _____ refers to two or more atoms held together by covalent bonds.

answer

molecule

question

A(n) _____ bond joins these two oxygen atoms.

answer

double covalent

question

Each water molecule is joined to _____ other water molecules by ____ bonds.

answer

four ... hydrogen

question

The unequal sharing of electrons within a water molecule makes the water molecule _____.

answer

polar

question

The tendency of an atom to pull electrons toward itself is referred to as its _____.

answer

electronegativity

question

In a neutral solution the concentration of _____.

answer

hydrogen ions is equal to the concentration of hydroxide ions

question

In order to maintain a constant pH, buffers act to either accept or release H+. True or False?

answer

true

question

Scientists recommend a diet rich in antioxidants to stay healthy. What occurs at the atomic level to explain this recommendation?

answer

Antioxidants stop the chain reaction of cellular damage caused by free radicals.

question

What is meant by the statement that water has a high specific heat?

answer

It can absorb a lot of energy without changing temperature.

question

Sweating is a useful cooling mechanism for humans because water

answer

takes up a great deal of heat in changing from its liquid state to its gaseous state.

question

The innermost electron shell of an atom can hold up to _____ electrons.

answer

2

question

Which of these relationships is true of an uncharged atom?

answer

The number of protons is equal to the number of electrons.

question

What determines the types of chemical reactions that an atom participates in?

answer

the number of electrons in the outermost electron shell

question

Cancer is caused by mutating DNA. What exactly do cigarette smoke and radiation do that can cause cancer?

answer

Cigarette smoke and radiation both cause free radicals, which damage DNA, leading to mutation.

question

What is a hydrogen bond?

answer

a weak bond between a slightly positive hydrogen atom and a slightly negative atom in a neighboring molecule

question

How do the hydrogen bonds between water molecules compare to the covalent bonds within water molecules?

answer

The hydrogen bonds are more easily broken than the covalent bonds.

question

How does water dissolve salt?

answer

The partial positive charges of the hydrogen atoms on water surround the negative charge of a chlorine ion.

question

Why are hydrophobic molecules such as fats and oils unable to dissolve in watery solutions?

answer

Hydrophobic molecules are nonpolar, so they can't form hydrogen bonds with water. Water molecules form hydrogen bonds with each other, excluding the hydrophobic molecules.

question

Because the specific heat of land is less than the specific heat of water, which of the following should be true?

answer

After a warm day, lakes should be warmer at night than the land around them.

question

Why does ice float?

answer

The hydrogen bonds in solid water force the molecules farther apart than the same bonds in liquid water.

question

Which basic property of a single water molecule accounts for all of its special features, including adhesion and cohesion, its ability to act as a solvent, and its high specific heat?

answer

the polar nature of water

question

A(n) ______ contains the same number of protons, but a different number of neutrons, than another form of the same element.

answer

isotope

question

___________ compounds do not interact with water

answer

hydrophobic

question

a(n) _______ is a subatomic particle found in an atoms nucleus that has no electrical charge.

answer

neutron

question

a(n) ______________________ is a chemical bond in which atoms share a pair of electrons

answer

covalent bonds

question

_____________ compounds will interact with water

answer

hydrophilic

question

If you examined the human body, which of the following combinations of elements would be most common?

answer

O, N, H, C

question

Radioactive isotopes are biological tools that are often used to

answer

detect brain tumors.

question

What determines the cohesiveness of water molecules?

answer

Hydrogen bonds

question

Water moves through a plant because of the property of

answer

cohesion

question

The human body must maintain a constant pH. In the blood, bicarbonate serves as a(n) ________ to help maintain the necessary pH.

answer

buffer

question

At the gym one day, you notice a new energy bar being sold that advertises quick energy for your workout. To impress you further, it is claimed that this bar contains only carbon, oxygen, and hydrogen atoms. What kind of biological molecule(s) would you be eating if you ate this energy bar?

answer

carbohydrates and lipids

question

The general class of biological molecules containing large, nonpolar regions, which make them insoluble in water, is called __________.

answer

lipids

question

Lipids contain fatty acids, which are made mostly of nonpolar bonds. Will these molecules be soluble or insoluble in water? Explain.

answer

they would be insoluble in water due to their nonpolar bonds

question

Proteins are polymers of __________.

answer

amino acids

question

Phospholipids contain a "head group" that is __________ and two fatty acid "tails" that are __________.

answer

hydrophilic;hydrophobic

question

"Organic" is a term that can have different meanings. What does this term mean to a chemist?

answer

organic compounds are compounds of carbon and hydrogen.

question

A nucleotide is composed of __________.

answer

a sugar, a phosphate group, and a nitrogen-containing base

question

Saturated fats __________.

answer

contain the max # of hydrogen atoms possible

question

Protein functions in cells include __________.

answer

defense, catalysis of biochemical reactions, structure and movement, and transport

question

During the process of polymerization (synthesis of biological polymers), water is __________, and the reaction is consequently called a __________ reaction.

answer

removed; dehydration

question

Which type(s) of organic molecules contain a phosphate functional group?

answer

both nucleic acids and phospholipids

question

Which of the following functional groups would you expect to help make an organic molecule soluble in water?

answer

a carbon backbone with many hydroxyl groups, OH

question

How are large organic molecules (macromolecules) synthesized?

answer

by a dehydration reaction utilizing monomers

question

Which of the following choices does not properly pair an organic compound with one of its building blocks (subunits)?

answer

nucleic acid-glycerol

question

If a lipid is completely saturated, would you predict it to be liquid or solid at room temperature?

answer

it would be solid at room temperature

question

Fat accumulates in our bodies when we overeat. This is because __________.

answer

lipids are a form of long term energy storage

question

A scientist is studying the metabolism of proteins in yeast and wants to follow the formation of proteins from the earliest possible point. In her experiment, she will feed the yeast's radioactive nutrients and follow the fate of the radioactivity in the cells. Which of the following atoms will allow her to exclusively follow proteins in the cell?

answer

radioactive sulfur

question

Carbohydrates __________.

answer

can function as a source of energy or can function as an extremely durable structural material, depending on the specific nature of the chemical bonds between subunits(monomers)

question

How are humans able to use the energy in the starch of a potato but not in the cellulose of celery?

answer

our bodies can't break the bonds in cellulose but can break those in starch.

question

Foods that are high in fiber are most likely to be derived from __________.

answer

plants

question

A characteristic of the carbon atom that contributes to its ability to form an immense diversity of organic molecules is its __________.

answer

ability to covalently bond with up to four other atoms

question

What is the difference between a simple sugar and a complex carbohydrate?

answer

complex carbohydrates are polymers of single sugars

question

Complex carbohydrates have numerous roles in plant cells, including __________.

answer

long term energy storage and giving of structure to plant cell walls

question

The quaternary level of protein structure __________.

answer

refers to a functional complex of two or more 3-d proteins

question

The earliest ancient Egyptians buried their dead in pits in the desert. The heat and dryness of the sand dehydrated the bodies relatively quickly, leaving lifelike mummies. The trunk region of the body dehydrates much more slowly than peripheral regions such as the hands or feet. Based on what you know about how biological molecules are broken apart by the process of hydrolysis, which regions of a mummy's body would give the most intact pieces of DNA?

answer

fingers

question

Proteins are macromolecules that can perform many different functions within an organism. This diversity of function is due to the unique nature of one of the protein macromolecule's four functional groups, which is bound to a central carbon atom. Which functional group is responsible for the wide diversity of function attributed to proteins?

answer

the R group

question

When a protein is denatured __________.

answer

the protein's normal three-dimensional structure is altered, leaving the primary structure and protein function compromised

question

Whether hair is naturally straight or curly is determined by __________.

answer

the appropriate location of disulfide bonds in keratin

question

Excess nitrogen wastes in our food are converted to urea. Which of the following types of foods would you expect to increase the levels of urea in your blood?

answer

meats that contain a lot of protein and legumes that contain a lot of nucleic acid

question

Which functional group is polar, acidic, and involved in peptide bonds?

answer

carboxyl

question

Which of the following forms the exoskeleton of insects, crabs, and spiders?

answer

chitin

question

What is the role of DNA and RNA in cells?

answer

preserving and expressing genetic information

question

The nucleotide base that is in DNA but not RNA is __________.

answer

thymine

question

Each fatty acid contains __________.

answer

a long chain of carbon and hydrogen and a carboxyl group at one end

question

Prions are __________.

answer

made of only proteins

question

The components of triglycerides are __________.

answer

one glycerol and three fatty acids

question

Which type of nucleic acid is found in the chromosomes of cells?

answer

DNA

question

Why are functional groups on organic compounds important?

answer

functional groups are more likely to participate in chemical reactions and are mainly responsible for the properties and chemical reactivity or organic molecules.

question

Which of the following carbohydrates is a disaccharide?

answer

sucrose

question

Which functional group helps to change gene expression when it is attached to nucleotides?

answer

methyl

question

Disulfide bridges form in proteins between __________ in the __________ structure.

answer

two cysteine molecules; tertiary

question

Obesity and a diet rich in saturated fats __________ LDL, while exercise __________ HDL.

answer

increases; increases

question

Complex macromolecules are separated into their component parts through the process of __________.

answer

hydrolysis

question

Cholesterol is used by cells __________.

answer

as a component of cell membranes, to insulate nerve cells in the brain, and as a building block for steroid types of hormones

question

You have identified a protein that is unable to form disulfide bridges. This would affect which of the following?

answer

tertiary structure of the protein

question

In which of the following molecules would rearranging the order of the subunits have an effect on molecular function?

answer

both protein and DNA

question

The bond that links amino acids in a protein is called a __________ bond.

answer

peptide

question

Adenosine Triphosphate (ATP) functions as a(n) __________.

answer

form of energy storage

question

The sequence of amino acids linked together form the __________ structure.

answer

primary

question

All of the following compounds contain carbon. Which one is an inorganic compound?

answer

carbon dioxide

question

You are telling your friend that organic molecules are all made up of carbon backbones with hydrogens. She doesn't understand how there can be so many different organic molecules if they all are made up of the same basic components. You explain that organic molecules

answer

vary because they possess different functional groups

question

What is the difference between carbohydrates and lipids?

answer

carbohydrates have mostly polar bonds and lipids do not

question

Which of these is NOT a lipid?

answer

RNA

question

Which of these is rich in unsaturated fats?

answer

olive oil

question

A function of cholesterol that does not harm health is its role _____.

answer

as a component of animal cell membranes

question

Why are organic molecules so diverse compared to inorganic molecules?

answer

the carbon molecules in an organic compound can make four bonds

question

Cholesterol, testosterone, and estrogen are examples of

answer

steroids

question

Which fact is most important in explaining why wrong base pairs are rarely incorporated into the double helix?

answer

Nucleotide pairing affects the action of DNA polymerase.

question

In an experiment, a scientist fed radioactive nucleotides to a cell that was previously non-radioactive. After the cell duplicated its DNA, which statement would be true?

answer

Each DNA helix would have one radioactive strand and one non-radioactive strand.

question

In DNA replication,

answer

the replica strands are complementary to the templates.

question

What is the difference between saturated and unsaturated fats?

answer

Unsaturated fats contain double bonds

question

What is the most common bond in a lipid?

answer

nonpolar covalent bonds

question

Enzymes are ________ that catalyze chemical reactions within the body.

answer

proteins

question

What is the difference between an organic compound and an inorganic compound?

answer

Organic compounds contain carbon and hydrogen. Inorganic compounds don't.

question

Proteins are polymers of _____.

answer

amino acids

question

What type of bond joins the monomers in a protein's primary structure?

answer

peptide

question

The secondary structure of a protein results from _____.

answer

hydrogen bonds

question

Tertiary structure is NOT directly dependent on _____.

answer

peptide bonds

question

Which nucleotide molecule functions as an energy carrier in the cell?

answer

ATP

question

What maintains the secondary structure of a protein?

answer

hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond

question

An atom's nucleus is composed of

answer

protons and neutrons.

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