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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

The smallest living unit within the human body is

_______ A)

a tissue. B)

a protein. C)

an organ system. D)

an organ. E)

the cell. Answer:

The watery component of the cytoplasm is called

_______ A)

extracellular fluid. B)

cytosol. C)

protoplasm. D)

interstitial fluid. E)

a colloidal gel. Answer:

Which of the following terms is not used to define the structure that separates the contents of a human cell from its surrounding medium?

_______ A)

plasma membrane B)

plasmalemma C)

cell membrane D)

cell wall E)

both A and D Answer:

Functions of the plasmalemma include all of the following, except

_______ A)

sensitivity to chemical changes in the extracellular fluid. B)

separation of the cytoplasm from the extracellular fluid. C)

regulation of exchange of materials with the extracellular environment. D)

structural support. E)

thermal insulation. Answer:

The plasma membrane is composed of

_______ A)

carbohydrate molecules. B)

a bilayer of proteins. C)

carbohydrates and lipids. D)

a bilayer of phospholipids. E)

carbohydrates and proteins. Answer:

Which of the following is not a function of membrane proteins?

_______ A)

act as anchors or stabilizers for the cell membrane B)

regulate the passage of ions C)

bind to ligands D)

act as carrier molecules for various solutes E)

cell nutrient Answer:

Functions of the glycocalyx include

_______ A)

identifying the cell for the immune system. B)

lubricating and protecting the cell membrane. C)

binding extracellular compounds. D)

all of the above E)

B and C only Answer:

Each of the following is an example of a nonmembranous organelle, except

_______ A)

lysosomes. B)

centrioles. C)

cilia. D)

cytoskeleton. E)

ribosomes. Answer:

Components of the cytoskeleton may include all of the following, except

_______ A)

microtubules. B)

thick filaments. C)

intermediate filaments. D)

microfilaments. E)

microsomes. Answer:

Tubulin is to microtubules as actin is to

______ A)

flagella. B)

microvilli. C)

microfilaments. D)

ribosomes. E)

intermediate filaments. Answer:

Which of the following cytoskeleton components moves the chromosomes during cell division?

______ A)

basal bodies B)

intermediate filaments C)

microfilaments D)

microtubules E)

thick filaments Answer:

Most of the ATP required to power cellular operations is produced in the

______ A)

cilia. B)

cytoplasm. C)

endoplasmic reticulum. D)

nucleus. E)

mitochondria. Answer:

In the mitochondrion, folds are to cristae as the contained fluid is to

______ A)

microvilli. B)

matrix. C)

cytosol. D)

actin. E)

basal body. Answer:

The components of ribosomes are formed within

______ A)

Golgi complexes. B)

nucleoli. C)

lysosomes. D)

mitochondria. E)

the endoplasmic reticulum. Answer:

Synthesis of lipids and glycogen takes place at the

______ A)

Golgi apparatus. B)

smooth ER. C)

rough ER. D)

ribosomes. E)

Which of the following consists of a network of intracellular membranes with attached ribosomes?

______ A)

smooth endoplasmic reticulum B)

rough endoplasmic reticulum C)

Golgi apparatus D)

mitochondria E)

nucleoli Answer:

Renewal or modification of the cell membrane is a function of the

______ A)

ribosomes. B)

mitochondria. C)

microtubules. D)

Golgi apparatus. E)

rough endoplasmic reticulum. Answer:

Organelles that absorb and neutralize drugs and toxins are

______ A)

peroxisomes. B)

endocytic vesicles. C)

nuclei D)

lysosomes. E)

toxisomes. Answer:

When activated, lysosomes function in

______ A)

synthesis of lipids. B)

synthesis of proteins. C)

digestion of foreign material. D)

cell division. E)

formation of new cell membranes. Answer:

Most of a cell's DNA is located in its

______ A)

nucleolus. B)

ribosomes. C)

Golgi apparatus. D)

lysosomes. E)

nucleus. Answer:

The control center for cellular operations is the

______ A)

ribosome. B)

nucleus. C)

endoplasmic reticulum. D)

Golgi apparatus. E)

The complex structures of DNA and protein found in the cell nucleus are

______ A)

nucleoplasm. B)

histones. C)

mitochondria. D)

chromosomes. E)

nucleases. Answer:

mRNA is needed to synthesize ________ in the cytoplasm.

______ A)

carbohydrates B)

proteins C)

lipids D)

phospholipids E)

all of the above Answer:

The triplet codes needed to specify a specific polypeptide chain are found in the

______ A)

anticodon. B)

codon. C)

gene. D)

polypeptide itself. E)

cytoplasm. Answer:

As each codon arrives at the active site of a ribosome, it attracts another molecule containing the anticodon. This molecule is called

______ A)

RER. B)

mRNA. C)

tRNA. D)

rRNA. E)

DNA. Answer:

The process of protein formation directed by mRNA is called

______ A)

mitosis. B)

auscultation. C)

translation. D)

transcription. E)

replication. Answer:

The process of forming mRNA is called

______ A)

ribolation. B)

translation. C)

replication. D)

transcription. E)

auscultation. Answer:

The movement of oxygen from an area of high concentration to an area of low concentration is an example of

______ A)

active transport. B)

filtration. C)

osmosis. D)

facilitated transport. E)

diffusion. Answer:

Diffusion of a substance across the cell membrane is influenced by all of the following, except

______ A)

the charge on the ion. B)

the presence of the membrane channels. C)

concentration gradient. D)

hydrolysis of ATP. E)

lipid solubility. Answer:

Water molecules and small ions enter a cell through

______ A)

lipid channels. B)

peripheral proteins. C)

defects in the lipid layer of the membrane. D)

peripheral carbohydrates. E)

channels formed by integral proteins. Answer:

A solution that contains a lower osmotic pressure than the cytoplasm of a cell is called

______ A)

merotonic. B)

isotonic. C)

hypotonic. D)

hypertonic. E)

homotonic. Answer:

"Spikes" form on a blood cell when it is placed in a(n) ________ solution.

______ A)

merotonic B)

hypertonic C)

homotonic D)

isotonic E)

hypotonic Answer:

The process by which molecules such as glucose are moved into cells along their concentration gradient with the help of membrane-bound carrier proteins is called

______ A)

facilitated diffusion. B)

exocytosis. C)

endocytosis. D)

active transport. E)

osmosis. Answer:

Facilitated diffusion differs from ordinary diffusion in that

______ A)

facilitated diffusion never eliminates the concentration gradient. B)

facilitated diffusion moves molecules from an area of higher concentration to lower concentration. C)

the rate of molecular movement is limited by the number of available carrier molecules. D)

facilitated diffusion consumes no ATP. E)

the rate of molecular movement is not limited by the number of available carrier molecules. Answer:

A process that requires cellular energy to move a substance against its concentration gradient is called

______ A)

facilitated transport. B)

osmosis. C)

diffusion. D)

active transport. E)

passive transport. Answer:

The intake of small membrane vesicles from the extracellular fluid is called

______ A)

active transport. B)

osmosis. C)

facilitated transport. D)

an ion exchange pump. E)

endocytosis. Answer:

The principal cations in our body fluids are ________ and ________.

______ A)

sodium; chloride B)

sodium; potassium C)

chloride; bicarbonate D)

calcium; magnesium E)

sodium; calcium Answer:

In order to maintain cellular homeostasis, an exchange pump ejects ________ ions from the cell and imports ________ ions.

______ A)

potassium; sodium B)

calcium; sodium C)

sodium; potassium D)

potassium; calcium E)

sodium; calcium Answer:

Which of the following about a cell's resting transmembrane potential is false?

______ A)

inside slightly more positive than outside B)

represents potential energy C)

controls muscular contraction and nervous signaling D)

inside slightly more negative than outside E)

depends on separation of + and — charges Answer:

The potential difference across the cell membrane is due to the separation of

______ A)

carbohydrate molecules. B)

water molecules. C)

cations and anions. D)

phospholipids and proteins. E)

acids and bases. Answer:

Changes in the transmembrane potential of a cell are involved in

______ A)

glandular secretion. B)

movement. C)

thought. D)

all of the above E)

A and B only Answer:

The stage in a cell's life cycle in which the cell performs its normal functions and prepares for division is called

______ A)

prophase. B)

telophase. C)

interphase. D)

metaphase. E)

anaphase. Answer:

A cell duplicates its chromosomes during the ________ phase.

______ A)

G2 Answer:

During mitosis, chromatids separate into daughter chromosomes during

______ A)

telophase. B)

interphase. C)

metaphase. D)

anaphase. E)

prophase. Answer:

During this phase of cell division, the chromosomes uncoil, the nuclear membrane forms, and cytokinesis occurs.

______ A)

metaphase B)

anaphase C)

interphase D)

prophase E)

telophase Answer:

As genes are functionally eliminated, the cell becomes limited in the range of proteins it can make. This specialization process is termed

______ A)

cellular activation. B)

structural integration. C)

adaptation. D)

differentiation. E)

apoptosis. Answer:

All of the following membrane transport mechanisms are passive processes, except

______ A)

diffusion. B)

osmosis. C)

facilitated diffusion. D)

vesicular transport. E)

The plasmalemma includes

______ A)

glycolipids. B)

integral proteins. C)

phospholipids. D)

all of the above E)

A and C only Answer:

The genetically programmed death of cells is called

______ A)

replication. B)

differentiation. C)

mitosis. D)

apoptosis. E)

metastasis. Answer:

Osmotic pressure

______ A)

forces water to move toward the higher solute concentration. B)

can be opposed by hydrostatic pressure. C)

forces water to move across a semipermeable membrane. D)

all of the above E)

A and C only Answer:

Membrane proteins perform which of the following functions?

______ A)

receptors B)

recognition C)

anchoring D)

enzymes E)

Which of the following about cytoplasm is false?

______ A)

semi-rigid texture B)

the material that fills a cell C)

extracellular fluid contains more protein D)

includes cytosol E)

includes cytoskeleton Answer:

Many proteins in the cytosol are ________ that accelerate metabolic reactions.

______ A)

lipids B)

ions C)

messengers D)

enzymes E)

carbohydrates Answer:

Extracellular fluid serves as

______ A)

a transport medium with large storage capacity. B)

a storage area. C)

a component of the phospholipid bilayer. D)

a transport medium. E)

a reserve area. Answer:

Microfilaments

______ A)

with myosin, produce cell movement B)

anchor the cytoskeleton to membrane proteins C)

control the consistency of cytoplasm D)

all of the above E)

B and C only Answer:

Tubulin is

______ A)

a protein that assembles into filamentous tubes (microtubules). B)

a protein that forms the tubular portion of the cytosol. C)

a lipid that assembles into filamentous tubes (microtubules). D)

a carbohydrate that assembles into filamentous tubes (microtubules). E)

a lipid that forms the ER. Answer:

These molecular motors carry materials in opposite directions along microtubules.

______ A)

kinesin and myosin B)

dynein and myosin C)

actin and myosin D)

dynein and kinesin E)

dynein and actin Answer:

Endocytosis is

______ A)

a form of anabolism. B)

a viral infection. C)

a method for transporting substances into the cell. D)

a method for packaging secretions. E)

a method for metabolizing within the cytosol. Answer:

Peroxisomes

______ A)

contain enzymes that break down hydrogen peroxide. B)

absorb and break down fatty acids, generating hydrogen peroxide in the process. C)

is another name for lysosomes. D)

both A and B E)

none of the above Answer:

Some cells contain large numbers of mitochondria while others have relatively few or none. This suggests that

______ A)

some cells are older than others. B)

cells with large numbers of mitochondria have a low energy demand. C)

cells with large numbers of mitochondria are short-lived. D)

cells with small numbers of mitochondria have a large ATP supply. E)

cells with large numbers of mitochondria have a high energy demand. Answer:

A mature red blood cell lacks a nucleus. Thus, it

______ A)

will be a long-lived cell. B)

is malformed. C)

can only divide once more. D)

cannot make new proteins and will be worn out within a few months. E)

can repair itself readily. Answer:

Histones are found in

______ A)

nucleosomes. B)

endosomes. C)

proteasomes. D)

lysosomes. E)

vesicles. Answer:

Chromosomes consist of ________ and ________.

______ A)

RNA; carbohydrates B)

water; RNA C)

DNA; lipids D)

RNA; proteins E)

DNA; proteins Answer:

Which organelle is most prominent in cells that make large amounts of protein?

______ A)

nucleolus B)

nucleus C)

mitochondria D)

chromosome E)

proteasome Answer:

Messenger RNA is vital to the cell because

______ A)

mRNA can leave the nucleus. B)

DNA can leave the nucleus. C)

mRNA cannot leave the nucleus. D)

DNA cannot leave the nucleus. E)

The functional units of DNA that contain the instructions for making one or more proteins are

______ A)

genes. B)

codons. C)

RNA. D)

ribosomes. E)

chromosomes. Answer:

Specific proteins are manufactured through the interaction of ________ and ________.

______ A)

multiple carbohydrates; three types of DNA B)

multiple enzymes; three types of DNA C)

multiple proteins; three types of DNA D)

multiple enzymes; three types of RNA E)

multiple enzymes; two types of RNA Answer:

Which of these transport processes always requires metabolic energy?

______ A)

impermeable B)

vesicular transport C)

carrier-mediated transport D)

diffusion E)

freely permeable Answer:

The skin swells and puckers during a long bath. This suggests that bath water is a(n) ________ fluid.

______ A)

isotonic B)

hypertonic C)

hypotonic D)

toxic E)

diffusion Answer:

Red blood cell shrinkage is to ________ as cell bursting is to ________.

______ A)

isotonic; hypotonic B)

lysis; crenation C)

isotonic; hypertonic D)

hypotonic; isotonic E)

crenation; hemolysis Answer:

Two types of vesicular transport include

______ A)

endocytosis and retrocytosis. B)

exocytosis and retrocytosis. C)

endocytosis and exocytosis. D)

passive diffusion and active diffusion. E)

pinocytosis and active transport. Answer:

A defense cell engulfing a bacterium illustrates

______ A)

pinocytosis. B)

exocytosis. C)

phagocytosis. D)

endocytosis. E)

receptor-mediated endocytosis. Answer:

During mitosis, two daughter cells form, each of which has

______ A)

a lesser number of chromosomes than the original cell. B)

a different number of chromosomes than the original cell. C)

twice as many chromosomes as the original cell. D)

half as many chromosomes as the original cell. E)

the same number of chromosomes as the original cell. Answer:

A unit in messenger RNA consisting of a set of three consecutive nucleotides is termed a(n)

______ A)

tRNA. B)

codon. C)

anticodon. D)

amino acid. E)

gene. Answer:

An impermeable carbohydrate that is often administered to patients suffering blood loss is

______ A)

isotonic saline. B)

saline solution. C)

glucose. D)

salt solution. E)

dextran. Answer:

An alternate term for tumor is

______ A)

primary metastasis. B)

cytoplasm. C)

neoplasm. D)

nucleoplasm. E)

benign malignancy. Answer:

What is the first part of the cell that is affected when the pH of extracellular fluid changes?

______ A)

the cytosol B)

nucleolus C)

plasmalemma D)

cytoskeleton E)

nucleus Answer:

Which form of endoplasmic reticulum modifies and packages newly synthesized proteins?

______ A)

ribosomal endoplasmic reticulum B)

rough endoplasmic reticulum C)

raised endoplasmic reticulum D)

smooth endoplasmic reticulum E)

proteosomes reticulum Answer:

Which of the following statements about the Golgi apparatus is false?

______ A)

sends transport vesicles to the RER B)

produces secretory vesicles C)

supplies new membrane components D)

receives transport vesicles from the RER E)

produces lysosomes Answer:

Which phase of the cell cycle has the most variable duration?

______ A)

G2 phase B)

G0 phase C)

G1 phase D)

S phase E)

V phase Answer:

Microtubules have which of the following functions?

______ A)

They move chromosomes during cell division. B)

They form structural components of organelles. C)

They provide a mechanism for changing the cell shape. D)

Molecular motors move along them. E)

The endoplasmic reticulum is responsible for

______ A)

lipid synthesis. B)

protein synthesis. C)

drug and toxin neutralization. D)

all of the above E)

both A and C Answer:

A substance containing atoms of different elements that are bonded together is called a(n)

______ A)

isotope. B)

molecule. C)

mixture. D)

compound. E)

solution. Answer:

Special catalytic molecules called ________ control chemical reactions in the human body.

______ A)

cytochromes B)

ribosomes C)

DNA D)

enzymes E)

cytozymes Answer:

All organic compounds in the human body contain all of the following elements, except

______ A)

carbon. B)

calcium. C)

oxygen. D)

hydrogen. E)

Which of the following is not a function of protein?

______ A)

metabolic regulation B)

movement C)

support D)

storage of genetic information E)

transport Answer:

Which of following properties of the cytoskeleton is false?

______ A)

made of cytobones B)

supports organelles C)

controls cell shape D)

moves organelles E)

provides cell strength Answer:

Which of following properties of microtubules is true?

______ A)

made of myosin B)

another term for microfilaments C)

interact with dynein and kinesin D)

made of actin E)

found only in the terminal web Answer:

Hemolysis may occur when a blood cell is placed into

______ A)

homotonic solution. B)

hypertonic solution. C)

merotonic solution. D)

isotonic solution. E)

hypotonic solution. Answer:

If a cell lacked the enzyme DNA polymerase, it could not

______ A)

form complementary sequences of DNA. B)

form spindle fibers. C)

form protein. D)

form a new nuclear membrane during telophase. E)

link segments of DNA together. Answer:

Compared to the extracellular fluid, cytosol contains

______ A)

almost no glycogen. B)

a higher concentration of amino acids. C)

a higher concentration of potassium ions. D)

a lower concentration of dissolved proteins. E)

almost no lipids. Answer:

Microfilaments

______ A)

anchor the cytoskeleton to integral proteins of the cell membrane. B)

are found in the cytoplasm radiating away from the centrosome. C)

are usually composed of myosin. D)

interact with filaments composed of tubulin to produce muscle contractions. E)

are hollow, filamentous structures. Answer:

If an animal cell lacked centrioles, it would not be able to

______ A)

metabolize sugars. B)

form the mitotic spindle. C)

move. D)

synthesize proteins. E)

produce DNA. Answer:

Each of the following statements concerning mitochondria is true, except one. Identify the exception.

______ A)

Respiratory enzymes are attached to the surface of the cristae. B)

The cristae increase the inner surface area of the organelle. C)

The matrix contains metabolic enzymes involved in energy production. D)

The mitochondria produce most of a cell's ATP. E)

The mitochondria contain no DNA. Answer:

Each of the following is a function of smooth endoplasmic reticulum, except

______ A)

detoxification of drugs. B)

synthesis of steroid hormones. C)

synthesis of triglycerides. D)

modification of protein. E)

storage and release of calcium ions. Answer:

The following is a list of the steps involved in the process of secretion by the Golgi apparatus.1. Material moves from cisterna to cisterna by means of transfer vesicles.2. Exocytosis.3. Products from RER are packaged into transport vesicles.4. Secretory vesicles are formed at the maturing face.5. Vesicles arrive at the forming face.6. Enzymes modify arriving proteins and glycoproteins.

The proper order for these is

______ A)

1, 3, 6, 4, 2, 5. B)

2, 3, 5, 6, 1, 4. C)

4, 3, 1, 6, 5, 2. D)

3, 5, 6, 1, 4, 2. E)

5, 6, 1, 4, 2, 3. Answer:

Imagine two rigid chambers separated by a rigid membrane that is freely permeable to water but impermeable to glucose. Side 1 contains a 10 percent glucose solution and side 2 contains pure water. At equilibrium, what will be the situation?

______ A)

The hydrostatic pressure will be higher in side 2. B)

The hydrostatic pressure will be higher in side 1. C)

Water will continue to move from side 2 to side 1. D)

No way to tell what the situation will be. E)

Water will continue to move from side 1 to side 2. Answer:

If the amount of chloride ion in blood plasma increases, which of the following would initially occur?

______ A)

The blood hydrostatic pressure will increase. B)

The blood hydrostatic pressure will decrease. C)

The blood osmotic pressure will decrease. D)

The blood osmotic pressure will stay the same. E)

The blood osmotic pressure will increase. Answer:

If the concentration of sodium chloride in the interstitial fluid surrounding cells decreases and the concentration of other solutes remains constant,

______ A)

the cells will shrink. B)

the cells will swell. C)

the fluid outside of the cells will become hypertonic. D)

the cells will not change. E)

the fluid outside of the cells will become isotonic. Answer:

Assume that the transport of a particular amino acid across the plasmalemma is observed (1) to occur only down its concentration gradient and (2) to slow when a similar amino acid is added to the extracellular fluid. The movement of the amino acid through the membrane is most likely by

_____ A)

osmosis. B)

facilitated diffusion. C)

active transport. D)

diffusion. E)

pinocytosis. Answer:

Generally, cells with a very brief interphase and lacking a G0 phase

_____ A)

lack the enzyme DNA polymerase. B)

are reproductive cells. C)

have brief life spans. D)

are stem cells. E)

do not exhibit cytokinesis. Answer:

There is a direct correlation between the potency of a general anesthetic such as ether and its ability to

_____ A)

bind to proteins. B)

interact with carbohydrates. C)

dissolve in lipids. D)

bind to DNA. E)

dissolve in water. Answer:

Cancer cells

_____ A)

do not form neoplasms. B)

have a slow mitotic rate. C)

are indistinguishable from normal body cells. D)

may exhibit metastasis. E)

generally form benign tumors. Answer:

The mRNA sequence that is complementary to the sequence ATC on DNA is

_____ A)

ATC. B)

UAG. C)

AUG. D)

TAG. E)

AUC. Answer:

The anticodon for the triplet UCA is

_____ A)

TCA. B)

AGT. C)

TGT. D)

AGC. E)

AGU. Answer:

Before the mRNA transcribed from a gene can be used to translate into a protein, it must be

_____ A)

edited to remove introns. B)

edited to remove exons. C)

transported into the cytoplasm. D)

both A and C E)

both B and C Answer:

Microscopic analysis of a tissue sample indicates that it contains abundant myosin and actin filaments. This tissue is probably formed from

_____ A)

reproductive cells. B)

nerve cells. C)

bone cells. D)

liver cells. E)

muscle cells. Answer:

Examination of a sample of glandular cells reveals an extensive network of smooth endoplasmic reticulum. Which of the following is the likeliest product of these cells?

_____ A)

transport proteins B)

antibodies C)

digestive enzymes D)

steroid hormones E)

protein hormones Answer:

Breathing faster and deeper eliminates more carbon dioxide from the body than normal breathing. Under these circumstances

_____ A)

more carbon dioxide will diffuse into the blood. B)

less carbon dioxide will diffuse out of the blood. C)

more carbon dioxide will diffuse out of the blood. D)

less carbon dioxide will diffuse into the blood. E)

the amount of carbon dioxide diffusion will remain unchanged. Answer:

A membrane transport process is found experimentally to have a saturation limit. Which of the following is a possible property of the process?

_____ A)

cotransport B)

active transport C)

carrier-mediated D)

energy-dependent E)

In a series of measurements of resting transmembrane potentials, the following values were recorded. Which one is likeliest to be an error?

_____ A)

—10 mV B)

+100 mV C)

—40 mV D)

—20 mV E)

—70 mV Answer:

Mitosis is to somatic cells as meiosis is to

_____ A)

sensory cells. B)

stem cells. C)

reproductive cells. D)

visceral cells. E)

plant cells. Answer:

Figure 3-1 The Anatomy of a Representative Cell

Use Figure 3-1 to answer the following question(s):

Which structure organizes the mitotic spindle during cell division?

_____ A)

6 Answer:

Synthesis of carbohydrates and lipids occurs in the structure labeled

_____ A)

8. Answer:

Which structure produces ATP for the cell?

_____ A)

6 Answer:

Which organelle renews the cell membrane and modifies and packages proteins for secretion?

_____ A)

8 Answer:

The structure labeled "1" permits the cell to

_____ A)

attach to neighboring cells. B)

trap bacteria. C)

increase surface area for increased membrane transport. D)

produce more cells. E)

swim in extracellular fluid. Answer:

Figure 3-2 The Plasmalemma

Use Figure 3-2 to answer the following question(s):

Which structure is water most likely to pass through?

_____ A)

8 Answer:

Which structure has a "gate" to control transport?

_____ A)

8 Answer:

Microfilaments are labeled

_____ A)

6. Answer:

Lipid molecules pass into the cell through the structure labeled

_____ A)

6. Answer:

What part of the plasmalemma is hydrophobic?

_____ A)

6 Answer:

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

The cytoplasm contains the fluid ________ and the suspended ________.

____________ Answer:

cytosol; organelles

Masses of insoluble material that are sometimes found in cytosol are known as ________.

____________ Answer:

inclusions

________ cells are all of the cells of the body except the reproductive cells (sperm and oocytes).

____________ Answer:

Somatic

The endoplasmic reticulum is an example of a(n) ________ organelle.

____________ Answer:

membranous

The extracellular fluid in most tissues is called the ________ fluid.

____________ Answer:

interstitial

Cilia and flagella contain 9 pairs of ________ surrounding a central pair.

____________ Answer:

microtubules

Ribosomes are composed of protein and ________.

____________ Answer:

The nucleus is surrounded by the ________.

____________ Answer:

nuclear envelope

Transfer of mRNA from the nucleus to the cytosol occurs through ________.

____________ Answer:

nuclear pores

A molecule of ________ contains all the codons needed to produce a particular polypeptide.

____________ Answer:

The enzyme ________ is required for the synthesis of mRNA.

____________ Answer:

RNA polymerase

Amino acids are transferred to the ribosome to be incorporated into a growing polypeptide chain by ________.

____________ Answer:

During the synthesis of proteins, amino acids are assembled in the proper sequence because each tRNA molecule that brings them to the ribosome has a(n) ________ that binds to a complementary codon in the mRNA.

____________ Answer:

anticodon

The start of each gene begins with a ________ segment.

____________ Answer:

promoter

A(n) ________ is a series of ribosomes attached to the same mRNA.

____________ Answer:

polyribosome or polysome

________ are permanent alterations in a cell's DNA that affect the nucleotide sequence of one or more genes.

____________ Answer:

Mutations

A point mutation involves a change in ________.

____________ Answer:

a single nucleotide

In cells that are not dividing, chromosomes uncoil to form a tangle of fine fibers known as ________.

____________ Answer:

chromatin

________ channels can open or close to regulate the passage of materials through the cell membrane.

____________ Answer:

The ________ of a membrane indicates how easy it is for substances to cross.

____________ Answer:

permeability

Cell membranes are said to be ________ because they allow some substances to pass but not others.

____________ Answer:

selectively permeable

Membrane-bound proteins that use metabolic energy to move ions across the plasmalemma are called ________.

____________ Answer:

ion pumps

In ________ one substance is transported into the cell, and another is transported out.

____________ Answer:

countertransport or antiport

Receptor molecules on the surface of cells bind specific molecules called, in general, ________.

____________ Answer:

ligands

Whenever positive and negative ions have been separated, a(n) ________ will be produced.

____________ Answer:

potential difference

The potential difference across the cell membrane is known as the ________.

____________ Answer:

transmembrane potential

The transmembrane potential in an undisturbed cell is called its ________.

____________ Answer:

resting membrane potential

Nuclear division of somatic cells is known as ________.

____________ Answer:

mitosis

________ is the process of duplicating chromosomes prior to cell division.

____________ Answer:

Replication

Special cells called ________ maintain tissues by unending cycles of cell division.

____________ Answer:

stem cells

The proper distribution of a cell's genetic material to two daughter cells is accomplished by the process of ________.

____________ Answer:

mitosis

The physical process by which a single animal cell separates into two cells is called ________.

____________ Answer:

cytokinesis

The process by which cells become specialized is called ________.

____________ Answer:

differentiation

A(n) ________ is a mutant of a regulatory gene that causes cancer.

____________ Answer:

oncogene

________ refers to identifying an individual on the basis of repetitive nucleotide sequences in his or her DNA.

____________ Answer:

DNA fingerprinting

A malignant neoplasm is often called a(n) ________.

____________ Answer:

cancer

Write out the term for tRNA.

____________ Answer:

transfer ribonucleic acid or transfer RNA

Write out the term for mRNA.

____________ Answer:

messenger ribonucleic acid or messenger RNA

Write out the term for rRNA.

____________ Answer:

ribosomal ribonucleic acid or ribosomal RNA

A change in a nucleotide sequence of a gene is termed a(n) ________.

____________ Answer:

mutation

________ are responsible for identifying and digesting damaged or denatured proteins.

____________ Answer:

Proteasomes

The ________ typically consists of five or six flattened membranous discs called cisternae.

____________ Answer:

Golgi apparatus

Recognition keeps the immune response from attacking ________, while still enabling it to recognize and destroy invading pathogens.

____________ Answer:

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 166)

When a person receives intravenous fluids to help build up blood volume, why is it important for the fluid to be isotonic?

Answer:

Intravenous fluids must be isotonic to prevent the cells from losing or gaining water. If the solution were hypertonic, the cells of the body would lose water, shrink, and possibly be harmed. On the other hand, the introduction of hypotonic fluid would cause the cells to swell and tissues to rupture.

Intravenous injection of KCl could be fatal. Why? Answer:

Increasing the amount of potassium ion in the extracellular fluid would result in more potassium (+ charges) entering the cell, leading to a resting potential that was more positive. This would disturb the resting transmembrane potential, upsetting muscle contraction (heart and skeletal muscles).

How would an inhibitor of the sodium-potassium exchange pump affect the resting potential? Answer:

The maintenance of a proper resting potential requires the sodium-potassium exchange pump, an active transport process. Without the pump, the cell would not be able to pump the sodium ion (+ charge) out and so the membrane potential would become more positive.

Define osmosis. Answer:

Osmosis is the transfer of water across a semipermeable membrane due to a difference in concentration of impermeable solute.

A) What are the similarities between facilitated diffusion and active transport? B) What are the differences?

Answer:

A) Both processes use carrier proteins and exhibit saturation. B) Facilitated diffusion is driven by a concentration gradient, does not consume ATP, and so is “passive,” whereas active transport is active, consumes ATP, and move a substance up its concentration gradient.

What role does the sodium-potassium exchange pump play in stabilizing the resting membrane potential? Answer:

By ejecting sodium ions from the cytosol and absorbing potassium ions from the extracellular fluid, the sodium-potassium pump maintains the K concentration gradient that leads to a negative resting membrane potential.

Differentiate between transcription and translation. Answer:

In transcription, RNA polymerase uses the nucleotide sequence on DNA to construct a complementary strand of mRNA. In translation, ribosomes use information carried by the mRNA strand and tRNA to synthesize the corresponding polypeptide.

During kidney dialysis, a person's blood is passed through a bath that contains several ions and molecules. The blood is separated from the dialysis fluid by a membrane that allows water, small ions, and small molecules to pass, but does not allow large proteins or blood cells to pass. What should the composition of dialysis fluid be for it to remove urea (a small molecule) without changing the blood volume (removing water from the blood)?

Answer:

For the dialysis fluid to remove urea without removing water, it should not contain urea. Because urea is a small molecule, it will diffuse through the dialysis membrane from an area of high concentration (the blood) to an area of low concentration (the dialysis fluid). To prevent an associated osmotic water movement, the dialysis fluid should have an osmotic concentration similar to that of blood plasma, but with higher concentrations of solutes such as bicarbonate ions or glucose. As urea diffuses into the dialysis fluid, glucose and bicarbonate diffuse into the blood; as a result, the solute concentrations remain in balance and no osmotic water movement occurs.

Which organelles are involved in membrane flow? Trace the route of a single integral membrane protein from formation to incorporation into the plasma membrane.

Answer:

All membranous organelles are involved in membrane flow. Those most directly associated are the ER, Golgi apparatus, secretory vesicles, and plasma membrane. A membrane protein would be synthesized in the RER, then flow through the cisternae to a transport vesicle. There the protein will be moved to the forming face of the Golgi apparatus, where it will slowly travel upward toward the maturing face, usually becoming modified along the way. Once reaching the maturing face of the Golgi apparatus, the protein would be embedded in the membrane of a secretory vesicle and transported to the plasma membrane. There the vesicle will fuse with the membrane, inserting the protein in the cell membrane.

B 100)

B 101)

D 102)

C 103)

D 104)

B 105)

E 106)

D 107)

E 108)

D 109)

C 110)

E 111)

B 112)

C 113)

B 114)

D 115)

C 116)

E 117)

C 118)

B 119)

E 120)

D 121)

A 122)

C 123)

cytosol; organelles 124)

inclusions 125)

Somatic 126)

membranous 127)

interstitial 128)

microtubules 129)

rRNA 130)

nuclear envelope 131)

nuclear pores 132)

mRNA 133)

RNA polymerase 134)

tRNA 135)

anticodon 136)

promoter 137)

polyribosome or polysome 138)

Mutations 139)

a single nucleotide 140)

chromatin 141)

Gated 142)

permeability 143)

selectively permeable 144)

ion pumps 145)

countertransport or antiport 146)

ligands 147)

potential difference 148)

transmembrane potential 149)

resting membrane potential 150)

mitosis 151)

Replication 152)

stem cells 153)

mitosis 154)

cytokinesis 155)

differentiation 156)

oncogene 157)

DNA fingerprinting 158)

cancer 159)

transfer ribonucleic acid or transfer RNA 160)

messenger ribonucleic acid or messenger RNA 161)

ribosomal ribonucleic acid or ribosomal RNA 162)

mutation 163)

Proteasomes 164)

Golgi apparatus 165)

self 166)