Mastering Biology Ch. 1&2

A particular atom of calcium has 20 protons, 21 neutrons, and 19 electrons. What is the electrical charge on this atom?

+1

Which group is the amino group? The figure shows a basic structure of amino acid. There are 4 labeled groups: group 1 is an -NH2 group, group 2 is a -COOH group, group 3 is the central carbon itself, and group 4 is an -R group.

1

Which of the following monomers is not paired correctly? a.) amino acids-proteins b.) glucose-carbohydrates c.) nucleotides-nucleic acids d.) All of these are paired properly.

D.) all of the above

Which of the following most accurately describes the role of DNA for our cells? See Section 2.4 (Page 31)

DNA includes instructions for building proteins.

This atom can form up to _____ single covalent bond(s). The figure shows a scheme for an atom structure. Two circles around the central sphere are illustrated. Two small balls are on the inner circle and four small balls are on the outer circle.

4

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

5

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

6

If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?

75

If I tested your intestinal fluid and found that it was basic, which of the pH values listed would best describe this solution? A) 6.8 B) 3.2 C) 1.2 D) 8.0

8.0

Which statement about monomers and polymers is true?

A monomer is the basic unit of a polymer.

Part complete A substance in which other substances are dissolved is known as a(n) ________.

A substance in which other substances are dissolved is known as a(n) ________. solvent

What is the primary role of an enzyme? See Section 2.4 (Page 31)

Enzymes speed reactions.

Humans belong to which of the following domains?

Eukarya

All internet websites with scientific data are reliable. See Section 1.5 (Page 11)

False

Only people who are going to be scientists need to be critical thinkers. See Section 1.5 (Page 11)

False

The pH scale measures ________.

H+ concentration

Regarding dehydration synthesis and hydrolysis, which of the following statements is true?

In dehydration synthesis, two monomers are joined together to form a polymer, and a water molecule is given off. In hydrolysis, a polymer separates into monomers, a water molecule splits, and part of the water molecule goes with each monomer.

Your roommate is experiencing heartburn and asks you to purchase her an antacid. Chemically speaking, how do you know that the antacid will help eliminate her pain?

It has a higher OH- concentration to increase the pH in her digestive tract.

Which of the following best characterizes a hydrogen bond?

It is a weak and temporary electrical attraction between two polar molecules.

You have information about a particle that contains 7 protons, 8 neutrons, and 8 electrons. Which of the following statements would be true?

It is an ion.

What does it mean when we say that organisms are grouped to show evolutionary relationships among them? See Section 1.2 (Page 5)

Organisms that are most similar overall are classified together.

Regarding the basic structure of the biological molecules, which of the following statements is true?

Proteins are composed of amino acids, carbohydrates are composed of simple sugars, and nucleic acids are composed of nucleotides.

Why isn't this insect drowning? An insect on a water surface. An insect (a water strider) stays on a water surface with four legs.

Surface tension.

Which statement about the "connecting ends" of a polymer is true?

All polymer buildups and breakdowns involve a hydrogen ion and a hydroxyl ion.

How does a population differ from an ecosystem?

An ecosystem includes a community, whereas a population does not.

In what ways are hydrogen bonds and ionic bonds similar?

Both are based on attraction between atoms that carry differences in electrical charge.

Which of these bonds is weakest?

The figure shows a bond between two identical molecules. Both molecules consist of a large sphere and two small spheres attached to it. A small sphere of the first molecule is labeled delta plus. Three dots go from it to the large sphere of the second molecule, this bond is indicated with brackets. The large sphere of the second molecule is labeled delta minus.

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

These atoms are isotopes.

What is the result of the animated process?

a positively charged sodium ion and a negatively charged chlorine ion

A theory is __________.

a wide-ranging explanation for natural events that has been extensively tested over time

Which of these relationships is true of an uncharged atom? a) The number of protons is equal to the number of electrons. b) The number of electrons is equal to the number of neutrons. c) The atomic mass is equal to the atomic number. d) The atomic mass is equal to the number of electrons. e) The number of neutrons is equal to the number of protons.

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

Any substance that when dissolved in water will give off H+ ions is referred to as a(n) ________.

acid

A trait that increases the chance that an organism will survive and reproduce in its natural environment is described as being __________.

adaptive

Part complete Which of the following is an example of a population?

all individuals of the same species in an area

A neutral atom must contain ________.

an equal number of protons and electrons

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

are different ions

Which of the following is not a characteristic of all living things? a) They respond to stimuli. b) They are composed of multiple cells. c) They contain carbohydrates, proteins, lipids, and nucleic acids. d) They have adaptive traits.

b) They are composed of multiple cells.

The complexity of living systems: a )is found only in humans. b) is also highly organized. c) is the single defining characteristic of living things. d) is unique to living systems.

b) is also highly organized.

Which of the following is NOT living? a) bacteria b) sand, rocks, and water c) archaea d) animals e) fungi

b) sand, rocks, and water

A substance consists of weak acids or bases designed to maintain a specific pH of a solution within a cell or a biological system. Which of the following describes this substance?

buffer

Which statement about evolution is most correct? a) Organisms evolve. These organisms represent the populations. b) Evolution just happens. It is not related to adaptation or characteristics of organisms. c) Populations with the best adaptive traits survive and reproduce better than populations with less adaptive traits. d) Populations with the most members are the most likely to evolve. e) Organisms that reproduce the most are most likely to evolve.

c) Populations with the best adaptive traits survive and reproduce better than populations with less adaptive traits.

Which of the following is NOT a characteristic of life? See Section 1.1 (Page 2) a) reproduction b) adaptation to environmental changes c) differentiation from cells to tissues d) complex chemical reactions

c) differentiation from cells to tissues

Which of the following carbohydrates is made by plants and is not digested by humans?

cellulose

What type of bond is joining the two hydrogen atoms? The figure shows a hydrogen molecule. Two small spheres are shown, and each is labeled H. There is a circle around each sphere. Two small balls are located at each intersection of the circles.

covalent

Which of the following is NOT an example of a good scientific question? a) Does dietary fat increase a woman's chance of developing breast cancer? b) Does obesity reduce one's life expectancy? c) Does temperature alter the rate of an enzymatic reaction? d) Does a full moon cause people to behave irrationally?

d) Does a full moon cause people to behave irrationally?

Living systems need energy to: a) grow larger. b) help maintain a constant internal environment. c) replace worn-out parts and build new parts. d) all of the above

d) all of the above

A statement such as "If human body temperature increases to a certain level, then critical proteins will be denatured" would most likely be associated with ________.

deductive reasoning

Part complete Changes in temperature or pH can cause a protein to lose its three-dimensional shape and become nonfunctional. This process is called __________.

denaturation

What is the highest level in the classification of life?

domain

A(n) _____ bond joins these two oxygen atoms. The figure shows an oxygen molecule. Two small spheres are shown, and each is labeled O. There are two circles around every sphere. Two small balls are on the inner circle of each sphere and four small balls are on the outer circle. In addition, four small balls are located at the intersection of the outer circles of both atoms.

double covalent

A forest contains many organisms and a variety of habitats. Therefore, it is considered to be a(n) __________. See Section 1.3 (Page 6)

ecosystem

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

electronegativity

Cells that possess a nucleus and a membrane system that establishes internal compartments belong in which of the following groups?

eukaryotes

True or false. All living things except bacteria are composed of cells.

false

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

four ... hydrogen

Enzymes __________.

have locations, known as active sites, to which the substrate binds

The process of homeostasis is:

how organisms maintain a constant internal environment.

Saturated fatty acids are so named because they are saturated with ________.

hydrogen

The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases.

hydrogen bonds

Part complete "An athlete who uses dietary supplements will perform better than one who doesn't." This statement would be an example of which of the following?

hypothesis

Part complete Which process used to solve problems in science involves accumulating facts through observation until the evidence leads to a general statement about nature?

inductive reasoning

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

ionic

Water has very special properties that not all chemicals share. Which of the following is not a property of water?

is nonpolar

Part complete Researchers testing new drugs usually give the drug to one group of people and give placebos, "sugar pills," to another group. The group receiving the placebo ________.

is the control group

An element with more or fewer neutrons than the same element as it appears on the periodic table is known as which of the following?

isotope

One particular atom of uranium has 238 neutrons. Another atom of uranium has 234 neutrons. These two atoms are most properly called ________.

isotopes

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

molecule

What type of carbohydrate is pictured? There is a structure of a molecule which looks like pentagon ring, where 1 carbon is replaced with an oxygen atom. Each carbon of the ring has either an -OH group or a -CH2OH group or a hydrogen atom attached.

monosaccharide

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

movement over great distances

What type of bond is found between amino acids?

peptide

A nucleotide is composed of a(n) _____.

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

These lipids have a hydrophobic part and a hydrophilic part.

phospholipids

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

polar

In this molecule, what type of bond is found between the oxygen and hydrogens? The figure shows two small spheres H attached to a large sphere O. The sphere O is marked with a minus, while each small sphere H marked with a plus.

polar covalent

Which of the following is the correct sequence of terms, from least complex to most complex? See Section 1.4 (Page 7)

population, community, ecosystem, biosphere

What is the best definition of a hypothesis? See Section 1.4 (Page 7)

possible explanation

Forward-looking eyes are characteristic of __________.

primates

Members of the domains Bacteria and Archaea are called ________ because they lack a nucleus and internal compartments.

prokaryotes

You received your genetic material from your parents in the form of DNA. Your DNA provides your cells with instruction for making ________.

proteins

What are the four major classes of biomolecules found in living organisms?

proteins, nucleic acids, lipids, and carbohydrates

Each element has a characteristic number of ________.

protons

What are the subatomic particles that make up the nucleus of the atom?

protons and neutrons

Which of the following things would be considered complex AND organized?

red blood cell in the human body

In the hot dessert sun, a snake seeks shelter in the shade of a rock; later in the evening, it will use the rock as a source of heat. What characteristic of life is it demonstrating? See Section 1.2 (Page 5)

response to the environment

In a covalent bond, the electrons between the atoms are ________.

shared

DNA is a molecule that directly allows a living thing to:

store information.

An example of stimuli that a plant would respond to is:

sunlight.

Part complete Living organisms are members of all of the levels listed; however, rocks are components of ________.

the ecosystem

What is homeostasis?

the maintaining of a relatively constant internal environment

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

the number of electrons in the outermost electron shell

True or False. Enzymes in the digestive tract catalyze hydrolysis reactions.

true

Which of the following formulas represents an amino acid?

C3H7NO2

Which of the following formulas represents a carbohydrate?

C8H16O8

What is the difference between covalent and ionic bonds?

Covalent bonds involve the sharing of electrons, whereas ionic bonds involve the transfer of electrons from one atom to another.

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

10

1 meter = _____ centimeters.

100

Imagine that the amino acid pictured is the first in a peptide chain. To which group would we add the next amino acid? The figure shows a basic structure of amino acid. There are 4 labeled groups: group 1 is an -NH2 group, group 2 is a -COOH group, group 3 is the central carbon itself, and group 4 is an -R group.

2

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

2

Part complete Oxygen, with an atomic number of 8, is a neutral atom and has ________ electrons in the first electron shell and ________ electrons in the second electron shell.

2; 6

If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand?

3'-TAAACG-5'