Chapter 1 Life

4 Which statement regarding the scientific method is false?

. Theories formed in everyday life carry the same validity as a scientific theory

The pH of blood is slightly basic. Which of the following would therefore be an expected pH for blood?

7.4

1.Which statement regarding the scientific method is FALSE?

A control group is always exposed to the factor being tested.

Which statement regarding acids and bases is correct?

Acids increase the proportion of hydrogen ions (H+), and bases reduce the proportion of H+.

Which domains contain organisms that lack a membrane bound nucleus?

Archaea & Bacteria

The three major domains of life are

Archaea, Bacteria, and Eukaryotes.

____ is a polysaccharide that is found in plant cell walls and accounts for their strength.

Cellulose

Which statement is false regarding science?

Correct scientific conclusions are permanent and never subject to change or refinement.

. Which of the following domains contains organisms that are adapted to life in harsh environments?

Domain Archaea

Which of the following is one of the domains of life?

Eukarya

Which of these is an example of inductive reasoning used to form a hypothesis?

Every fungus that has ever been studied absorbs its food; therefore, food absorption is characteristic of fungi.

What is the correct format for the binomial name of human beings?

Homo sapiens

Which of the following statements about hydrogen bonding is incorrect?

Hydrogen bonding occurs only between water molecules.

3 Which statement regarding the scientific method is false?

Hypotheses are finally proven as absolutely true or false.

Which of the following radioactive isotopes are used to detect whether or not an individual has a healthy thyroid?

I^131

Which of the following is not a property of water that results from hydrogen bonding?

Ice melts at -100°C.

Which statement about living organisms is not correct?

Living organisms create energy.

Nutrient molecules are used to build cellular structures or for energy. This best represents which characteristic of life?

Living things acquire materials and energy from the environment.

The bones in a bird are hollow, reducing its weight for flight. This is an example of which characteristic of life?

Living things are adapted.

. The body temperature in humans is maintained around 37C. Which characteristic of life does this information represent?

Living things are homeostatic.

Organs are composed of tissues, which are composed of cells. This is an example of which characteristic of life?

Living things have levels of hierarchical organization.

.2 Which statement regarding the scientific method is false?

Original hypotheses are formed after an experiment.

Corn belongs to the kingdom

Plantae.

Which is the least importance when concerning the preservation of ecosystems?

Preservation of ecosystems allows humans to exploit as many resources as possible.

Hemoglobin is a protein composed of two pairs of polypeptide chains. What is the highest level of protein structure represented by hemoglobin?

Quaternary

Which of the following statements is NOT true of chemical bonds?

Salts are covalently bonded.

Some students consume large amounts of coffee and so-called energy drinks to help them stay alert when studying. You notice that many who engage in this practice seem to do poorly on exams. Suppose you want to investigate the relationship between caffeine consumption and exam performance. Which of the following statements would be an appropriate hypothesis?

Students who consume large amounts of caffeine while studying will have lower exam scores than those who consume less caffeine.

If a new anti-cancer drug is found to be effective in initial tests with mice, what might researchers conclude?

The drug is effective in the mouse model; it must still be tested in humans.

. Which statement concerning reproduction is false?

The offspring of multi cellular organisms tend to be identical to the parent.

Rain falling in the northeastern U.S. has a pH between 5.0 and 4.0. Normally, rainwater has a pH of about 5.6. Which of the following statements is not correct?

The pH of the rainwater has changed from neutral to acidic

Determine what would happen to an individual's proteins if they developed a fever of 103o F for several days.

The proteins would denature due to the increase in body temperature and would become unable to function correctly

In the late 1800s, Louis Pasteur was searching for a vaccine for anthrax in livestock. One French veterinarian had a local reputation for being able to cure anthrax by applying oils and wrapping the animal in cloth to induce a fever. Pasteur also knew that some animals got well on their own when left untreated. Pasteur tested the effectiveness of the local veterinarian's methods by injecting four cattle with anthrax bacteria. He then directed the veterinarian to perform his procedures on two cattle. The other two cattle were left alone. What is the rationale for Pasteur's experimental design?

Two cattle represent a test of the treatment; two serve as a control to determine the likelihood of survival without treatment.

Hydrogen bonding produces which of the following properties of water? .

Water is less dense as ice than as liquid water.

The moon lacks life and varies dramatically in temperature. If we could keep a layer of water spread on the surface of the moon, what effect would it have?

Water would absorb and hold heat and moderate the temperature extremes.

59. In the late 1800s, Louis Pasteur was searching for a vaccine for anthrax in livestock. One French veterinarian had a local reputation for being able to cure anthrax by applying oils and wrapping the animal in cloth to induce a fever. Pasteur also knew that some animals got well on their own when left untreated. Pasteur tested the effectiveness of the local veterinarian's methods by injecting four cattle with anthrax bacteria. He then directed the veterinarian to perform his procedures on two cattle. The other two cattle were left alone. One cow from each group died and the other one in each group survived. Pasteur dismissed the veterinarian's procedure as ineffective, but he also considered this to be a poor test. Why would he consider this to be a poor test?

With such a small group you can't determine if survival was dependent on the treatment or random chance.

A covalent bond is .

a sharing of electrons between two atoms.

When two glucose molecules combine they form a disaccharide molecule and

a water molecule.

Aspirin is acetyl salicylic acid and can therefore pose a problem to people who have ulcers. Bufferin is an alternative to aspirin that uses a buffer to neutralize this effect by

adding chemicals that take up excess hydrogen (H+) ions.

You are conducting an experiment to determine which brand of fertilizer results in the greatest amount of fruit production by tomato plants. In this example, the response variable would be the

amount of fruit produced by the tomato plants.

The molecular structure shown here is

an amino acid.

Since pure water is neutral in pH, it contains

an equal number of hydrogen ions (H+) and hydroxide ions (OH-).

In water, a weak hydrogen bond occurs between hydrogen in one molecule and

an oxygen atom in a different molecule.

All carbohydrate molecules

are composed of atoms of C, H, and the functional group -OH.

Which of these combinations would be found in a nucleotide?

base-sugar-phosphate

The layer where organisms can exist on the surface of the earth is the

biosphere.

Hydrolysis of a fat results in

both glycerol and fatty acids.

Calcium chloride, CaCl2, is an ionic compound in which

calcium has lost two electrons.

Maltose is classified as a

carbohydrate.

The smallest unit that has all of the characteristics of life is the:

cell

Which sequence correctly lists the different levels of biological organization, from the smallest and simplest to the largest and most complex?

cells-tissues-organs-organ systems-organisms

When comparing energy and chemicals in an ecosystem,

chemicals cycle over and over again but energy flows through once.

The most important factor that determines where ecosystems are located on the globe is

climate.

You notice that rain water forms "beads" on your car. This is an example of what property of water?

cohesion

. All the organisms of various species living within a given area constitute a(n)

community.

Two molecules of glucose combine to form a disaccharide molecule during a(n) ________ reaction.

dehydration

he final shape of a protein is very important to its function. When proteins undergo an irreversible change in shape called ________________ they ________________ perform their usual functions.

denaturation/cannot

Which of the following sequences correctly lists the bonds in order of strongest to weakest?

double covalent - single covalent - ionic - hydrogen

A community of organisms along with their physical environment constitutes a(n)

ecosystem.

You are conducting an experiment to determine what concentration of disinfectant is most effective in killing bacteria. In this example, the concentration of disinfectant would represent the

experimental variable.

A long chain of carbon atoms with hydrogen atoms attached, ending in the acidic group -COOH would be a(n)

fatty acid.

An ion is an atom that

has a net charge.

When you are overheated, you perspire, and when you are too cold, you shiver to generate heat. Which property of life is best represented by this example?

homeostasis

Which type of bond formation is responsible for the properties of water?

hydrogen

Water is a liquid at room temperature. This is due to

hydrogen bonding between water molecules.

The water strider is an insect that skates across the water without sinking. The tips of its feet must be coated with molecules that are

hydrophobic. .

A possible explanation for a natural event, based on observations and past knowledge, is a

hypothesis.

The atomic mass of an element

is determined by the number of protons and neutrons it contains.

To measure the activity of the human brain during certain thought processes, a short-lived radioactive sugar is injected in the carotid artery and is utilized by those cells that are most active. This shows up on a PET scan and demonstrates the detection of

isotopes.

Buffers

keep the pH within normal limits.

You have discovered a previously unknown organism. It is multicellular, with a filamentous form, and absorbs food from its environment. Upon microscopic examination, you see that the cells have nuclei. How would you classify this organism?

kingdom Fungi

A multicellular, photosynthetic organism with complex, specialized cells and tissues would most likely be assigned to

kingdom Plantae.

If neutral atoms become positive ions, they

lose electrons.

When researchers test a new human cancer drug using mice, the mice constitute the

model.

Ever since the antibiotic drug penicillin was discovered in 1928, the incidence of resistant bacteria has steadily increased as a direct result of

natural selection.

Which answer choice lists the steps of the scientific method in the correct order?

observation, hypothesis, experiment, data collection, conclusion

Which level of biological organization is composed of several tissues?

organ

A physician specializes in surgery involving the following group of organs: mouth, esophagus, stomach, and intestines. Overall, what is the highest level of organization that this physician is specialized in?

organ system

. An unmanned spacecraft has been sent to another planet to detect other life forms that might be quite different from those on Earth. If the probe could only send back one still picture, which property or properties of life would be observable in a picture?

organization

. A piece of petrified wood was once part of a living organism that has had its tissues replaced by minerals. Which property of life will still be present in the wood?

organization.

What type of bond will connect the amino acids in a protein?

peptide

Which of the following types of lipids is the most abundant constituent of cell membranes?

phospholipid

Glycogen is a

polysaccharide used to store glucose/energy.

All the banded sunfish () in a pond would comprise a(n)

population.

The _____ structure of a protein consists of the sequence of the amino acids joined together by peptide bonds.

primary

A genetic mutation can cause a change in the sequence of the 20 amino acids used to build proteins. Such a change is a change to the protein's

primary structure, but this will likely alter higher levels of structure as well.

In the search to discover the agents that cause mad cow disease, scrapie in sheep, and CJD and kuru in humans, diseased brain tissues were passed through a fine filter to remove bacteria. The filtrate was still infectious, indicating that something smaller than bacteria, either viruses or organic molecules, must be the causative agent. If a virus was responsible for these brain diseases, then the infectious agent would contain either RNA or DNA. Other possibilities were that the agent was a carbohydrate, fat, or protein. Tissue filtrates were treated with agents that destroyed just one of these chemicals and then injected into a healthy animal, with the results as follows. What is the infectious agent? ·Amylase digests carbohydrates; tissue filtrate still infects healthy test animal. ·Lipase digests fats; tissue filtrate still infects healthy test animal. ·Formaldehyde and/or heat denatures DNA and RNA; tissue filtrate still infects healthy test animal. ·Trypsin digests protein; tissue filtrate does not infect healthy test animal.

protein

Enzymes are organic compounds classified as

proteins.

Which of the following subatomic particles will be found within the nucleus of the atom?

protons and neutrons

The nucleus of an atom contains

protons and neutrons.

The primary function of carbohydrates is

quick fuel and short-term energy storage.

The proposed cause of CJD and kuru in humans, mad cow disease, and scrapie in sheep is a change in a brain protein. Disease victims appear to have a protein that should normally contain alpha helices but instead they have changed into a protein made of beta pleated sheets. The disease appears to spread when the abnormal protein comes into contact with the normal protein, causing it to become deformed. Which level of protein structure is associated with these diseases?

secondary

Which type of lipid molecule is characterized by a backbone of four fused rings?

steroid

Cholesterol is a component of cell membranes and is an example of which type of lipid?

steroids

If an element has an atomic number of 15, then

the atom has 15 electrons.

The lower the pH

the more acidic the solution.

The chemical reactivity of an element is dependent on

the number of electrons in the outermost shell.

isotopes of a given element have

the same number of protons but differ in atomic mass.

When an ionic bond forms, electrons are

transferred from one atom to another.

Polar covalent bonds result from

unequal sharing of electrons in a covalent bond.

Which of the following radiation uses is the one that is most likely to have both beneficial and harmful consequences?

using radiation to treat a cancer patient