HCS 212 TEST BANK 2

The study of the structure and function of cells is

A) biochemistry.

B) gross anatomy.

C) cytology.

D) electron microscopy.

E) phrenology.

c

Which of the following shows the fine structure of a plasmalemma (cell membrane) and the details of intracellular structures?

A) light microscopy

B) transmission electron microscopy

C) scanning electron microscopy

D) ultrasound

E) magnetic resonance imaging

b

Cells float in a watery medium called

A) cytoplasm.

B) extracellular fluid.

C) cytosol.

D) cellular fluid.

E) None of the answers are correct.

b

Which of the following describes phospholipids in the plasmalemma?

A) The lipid tails are hydrophobic.

B) The lipid tails are hydrophilic.

C) The phosphate heads are hydrophobic.

D) The tails are at the surface. E) The heads are on the inside.

a

The viscous, superficial coating on the outer surface of the plasmalemma is called the

A) glycocalyx.

B) pseudopodia.

C) inclusions.

D) tubulin.

E) cytosol.

a

How do peripheral proteins contribute to the structure of the plasmalemma?

A) They form a structural element by being embedded in the plasmalemma.

B) Some form channels to permit passage of water molecules, ions, and small water-soluble compounds into and out of the cell.

C) Some may function as catalysts or receptor sites to signal through the plasmalemma.

D) They are attached to only one side of the membrane.

E) None of the answers are correct.

d

Substances that enter the cell usually do so through the

A) cholesterol.

B) glycocalyx.

C) glycolipids.

D) integral proteins.

E) peripheral proteins.

d

The general functions of the plasmalemma include

A) physical isolation of the cell contents from the extracellular fluid.

B) regulation of exchange of materials with the environment.

C) sensitivity to changes in the extracellular fluid.

D) structural support of the cell.

E) All of the answers are correct.

e

Which statement describes how the plasmalemma is used in communication and sensitivity?

A) It serves as a storage site for large amounts of proteins for future use by the cell.

B) It effectively isolates the cytoplasm from the surrounding fluid environment.

C) It contains gated channels that can be opened or closed to regulate the passage of materials.

D) It acts as a site for the attachment of glycoproteins and glycolipids, which act as receptors for molecules present in the extracellular fluid.

E) It provides for specialized connections between neighboring cells.

d

Because the plasmalemma blocks some substances and allows others through, it is referred to as being

A) structurally rigid.

B) impermeable.

C) selectively permeable.

D) freely permeable.

E) both structurally rigid and selectively permeable.

d

Which of the following is a passive process for material movement across a plasmalemma?

A) bulk flow

B) endocytosis

C) exocytosis

D) active transport

E) facilitated diffusion

e

An active process for transporting liquid across a plasmalemma is

A) phagocytosis.

B) pinocytosis.

C) bulk flow.

D) exchange pumps.

E) None of the answers are correct.

b

Iron ions and cholesterol are brought into the cell by the process of

A) pinocytosis.

B) phagocytosis.

C) receptor-mediated pinocytosis.

D) bulk transport.

E) None of the answers are correct.

c

How does oxygen pass through the plasmalemma?

A) across the membrane's lipid portion

B) through membrane channels

C) always by passive processes

D) always by active transport

E) both through membrane channels and always by passive processes

a

Processes involved in the movement of substances across a membrane at the expense of ATP are classified as

A) osmosis.

B) diffusion.

C) filtration.

D) facilitated diffusion.

E) active transport.

e

What is the term for water movement across a membrane from high concentration to low concentration?

A) facilitated diffusion

B) osmosis

C) filtration

D) active transport

E) None of the answers are correct.

b

The two major cations in the body are

A) calcium and sodium.

B) chloride and bicarbonate.

C) sodium and chloride.

D) sodium and potassium.

E) magnesium and chloride.

d

The extracellular fluid contains high amounts of

A) potassium ions.

B) dissolved and suspended proteins.

C) amino acids.

D) sodium ions.

E) lipids.

d

Which of the following statements describes cytosol?

A) The term encompasses all material inside the cell.

B) The fluid content of the cell.

C) It contains much less protein than the extracellular fluid.

D) It contains large amounts of carbohydrates.

E) It includes the intracellular structures known as organelles.

b

________ are common inclusions in the cytosol of fat cells.

A) Glycogen granules

B) Suspended proteins

C) Lipid droplets

D) Dissolved proteins

E) Metabolic enzymes

c

Which of the following is another name for cytosol?

A) intracellular fluid

B) gelatin

C) interstitial fluid

D) extracellular fluid

E) cytoplasm

a

Protein producing organelles are the

A) nucleus.

B) Golgi apparatus.

C) mitochondria.

D) lysosomes.

E) ribosomes.

e

Which of the following is a nonmembranous organelle?

A) Golgi apparatus

B) microvilli

C) nucleolus

D) centriole

E) All of the answers are correct.

d

The functions of microtubules include

A) holding open gated channels in the plasmalemma.

B) changing the shape of the cell.

C) moving organelles around the cell.

D) forming small, finger-shaped projections from the plasmalemma.

E) changing the shape of the cell and moving organelles around the cell.

e

Which of the following is a function of microtubules?

A) being part of the spindle apparatus

B) provide strength to the cell

C) stabilize position of organelles

D) attaches the plasmolemma to the underlying cytoplasm E) assist in DNA replication

a

Which of the following is located in the cytoplasm?

A) DNA

B) chromatin

C) envelope

D) nucleolus

E) centriole

e

What is the major function of ribosomes?

A) manufacture proteins

B) produce ATP

C) package proteins

D) move through the extracellular fluid

E) reproduce themselves

a

Thick filaments

A) form intermediate filaments to stabilize organelle position.

B) are stable structures that do not change once formed.

C) are called neurofilaments in neurons.

D) interact with actin to produce contractions.

E) form the spindle apparatus during cell division.

d

If a cell lacked centrioles, it would be unable to

A) direct the movement of chromosomes during cell division.

B) move through the surrounding fluid.

C) replicate its own DNA.

D) manufacture proteins.

E) move fluids or solutes across the plasmalemma.

a

Which statement describes cytoplasmic vesicles?

A) They are formed by all types of endocytosis.

B) Contents are toxic to the cell.

C) They never contain extracellular fluids.

D) They only contain solids.

E) They have a membrane that is very different from the plasmalemma.

a

Which cellular operation occurs in the smooth endoplasmic reticulum?

A) regulation of protein synthesis

B) synthesis of RNA

C) DNA replication leading to cell division

D) manufacture of carbohydrates and lipids

E) synthesis of ribosomes via nucleoli

d

The nucleus of a cell

A) is completely enclosed with no way in or out.

B) contains only the DNA.

C) is surrounded by a double membrane.

D) it contains large proteins that form chromosomes and are the genetic material for the cell.

E) has all of the above attributes.

c

Which of the following is a vesicle?

A) communicating junction

B) lysosome

C) tight junction

D) anchoring junction

E) hyaluronan

b

Manufactured proteins from the rough endoplasmic reticulum are delivered to the Golgi apparatus by

A) cisternae.

B) bulk transport.

C) transport vesicles.

D) ribosomal RNA.

E) None of the answers are correct.

c

Recycling and changing the plasmalemma is the major function of which organelle?

A) lysosomes

B) Golgi apparatus

C) peroxisomes

D) mitochondria

E) cytoskeleton

b

Which organelle determines the structural and functional characteristics of the cell by controlling RNA and protein synthesis?

A) endoplasmic reticulum

B) Golgi apparatus

C) ribosomes

D) mitochondria

E) nucleus

e

Which of the following allows the nucleus to produce ribosomes?

A) nuclear envelope

B) nuclear pore

C) nucleoplasm

D) nucleosome

E) nucleolus

e

Communicating junctions are found in high quantities in the A) heart.

B) brain.

C) lungs.

D) eyes.

E) bones.

a

In correct order from beginning to end, cells undergoing mitosis pass through A) anaphase, prophase, interphase, and telophase.

B) metaphase, prophase, telophase, and anaphase.

C) interphase, telophase, metaphase, and prophase.

D) prophase, metaphase, anaphase, and telophase. E) telophase, anaphase, metaphase, and prophase.

d

Cytokinesis

A) usually begins after telophase.

B) separates the daughter cells after mitosis. C) is the last phase of mitosis.

D) completes the process of mitosis.

E) All of the answers are correct.

b

Which of the following events occur during metaphase?

A) Chromosomes align at the equator of the cell.

B) Microtubules form the spindle apparatus.

C) Daughter chromosomes move toward the opposite ends of the cell.

D) Centrioles move apart.

E) All of the answers are correct.

a

Which of the following processes occurs during interphase?

A) Chromatid pairs separate.

B) Chromatin condenses into chromosomes.

C) DNA replicates.

D) A cleavage furrow forms.

E) The mitotic spindle forms.

c

Which of the following is true of cell division?

A) Its importance diminishes after an individual grows to maturity.

B) It requires accurate duplication (replication) of the genetic material.

C) Each dividing cell produces four cells at a time.

D) It requires mitosis only to produce two daughter cells.

E) Protein synthesis in preparation for division occurs during the S phase of interphase.

b

Which sequence correctly traces the steps of DNA replication?

(1) Weak bonds between nitrogenous bases of the DNA are disrupted.

(2) DNA strands unwind.

(3) DNA polymerase binds to exposed nitrogenous bases.

(4) Ligases link together short complementary chains of nucleotides.

(5) Nitrogenous bases of the DNA strand attract complementary nucleotides.

A) 1, 2, 3, 4, 5

B) 1, 2, 3, 5, 4

C) 5, 4, 3, 2, 1

D) 1, 3, 5, 2, 4

E) 4, 2, 3, 1, 5

b

The fundamental units of all plant and animal tissues are ________.

cells

A plasmalemma separates the cell contents, or ________, from the extracellular fluid.

cytoplasm

Peripheral proteins are attached to the surface of the plasmalemma, while ________ proteins are embedded within the membrane.

integral

The membrane of a cell is composed of a ________ bilayer.

phospholipid

A phospholipid has two functionally different areas: hydrophilic heads and ________ tails.

hydrophobic

"Little organs" inside a cell that have specialized functions are called ________.

organelles

The main components of the plasmalemma include phospholipids, glycolipids, proteins, and ________.

cholesterol

The glycocalyx is made of mostly glycoproteins and ________.

glycolipids

Some integral proteins form ________ that let water molecules, ions, and small water-soluble compounds cross the membrane.

channels

hannels in the plasmalemma that can open or close to regulate the passage of water, small ions, and water-soluble molecules are called ________ channels.

gated

Substances that are able to pass directly through the phospholipid bilayer are lipids, lipid- soluble molecules, and ______, such as O2 and CO2.

soluble gases

The term used to describe the property of being able to pass through the membrane is ________.

permeability

Because the plasmalemma is relatively permeable to water, the process of ________ keeps water concentration in the extracellular and intracellular fluids equal.

osmosis

Moving a solute or solvent across a membrane against a concentration gradient is a(n) ________ process that requires an expenditure of ATP.

active

A passive process that involves movement of substances from an area of higher concentration to an area of lower concentration is called ________.

diffusion

An active transport process that produces cytoplasmic vesicles filled with extracellular fluid is called ________.

pinocytosis

The process of engulfing solid objects that may be as large as the cell itself is called ________.

phagocytosis

Compared with extracellular fluid, a sample of ________ has a relatively high concentration of both potassium ions and dissolved or suspended proteins, but little carbohydrate.

cytosol or intracellular fluid

The cytosol contains a high concentration of potassium ions, while the extracellular fluid usually contains a high concentration of ________ ions.

sodium

Microfilaments are slender protein strands, usually composed of the protein ________.

actin

Microtubules, intermediate filaments, and microfilaments are all part of the cell's ________.

cytoskeleton

________ filaments provide strength, stabilize the position of organelles, and transport materials within the cytoplasm; they are defined by their size rather than composition, which varies from cell to cell. (Note: Be sure the first letter of your answer is capitalized).

Answer: Intermediate

intermediate

Interaction between the ________ causes a waving or bending that results in the stiffening of microvilli and the cytoskeleton to which they are anchored.

microfilaments

New membrane is being added continually by the ________, resulting in membrane turnover at the surface of the cell.

Golgi apparatus

Chemical communication between the nucleus and the cytosol occurs through ________.

nuclear pores

At intervals, DNA coiled around histones forms complexes called ________; these complexes may also coil around other histones.

nucleosomes

The ________ of the cell packages materials for exportation.

Golgi apparatus

The nucleus is separated from the cytosol by the ________.

nuclear envelope

The continual movement and exchange of vesicles to and from the plasmalemma is called ________.

membrane flow

In the nucleus, DNA strands form large complex structures known as ________.

chromosomes

The ________ serves as the control center for cellular functions.

nucleus

The nucleus contains all the information needed for the synthesis of about 100,000 ________.

proteins

Proteins called ________ are channel proteins that allow the passage of metabolites between neighboring cells.

communicating junctions

When skin cells are shed a few at a time, rather than in the usual large sheets, it can be hypothesized that the ________ junctions that hold them together might have broken down.

anchoring

Large areas of opposing plasmalemma may be interconnected by transmembrane proteins called ________ or CAMs.

cell adhesion molecules

A ________ is a cell junction that binds the cell membranes of neighboring cells tightly to one another preventing the passage of material between the cells.

tight junction or occluding junction

The process that involves the phases prophase, metaphase, anaphase, and telophase is called ________.

mitosis

During ________, chromatid pairs separate and the daughter chromosomes move toward opposite ends of the cell.

anaphase

Somatic cells spend the majority of their functional lives in the phase called ________.

interphase

In cells preparing for division, the phase of the life cycle that is most variable in length is ________ of interphase.

G1

A passive process that allows passage of small inorganic ions and lipid-soluble materials in all cell types is called diffusion.

true

A passive process that involves the movement of water (solvent) molecules toward solute concentrations across a membrane is called facilitated diffusion.

false

A passive process wherein carrier molecules transport materials down concentration gradients across a membrane is called osmosis.

false

Endocytosis is an energy-requiring process where vesicles containing fluid or solid materials from the extracellular environment are formed.

true

Active transport is an energy-requiring process whereby ions and possibly other materials are moved across a membrane by carrier molecules, which work regardless of any concentration gradients.

true

Vesicles that contain oxidases and catalase are called peroxisomes.

true

Structures responsible for essential cleanup and recycling functions inside the cell are called lysosomes.

true

Organelles that produce most of the ATP required by the cell are called ribosomes.

false

The endoplasmic reticulum is the organelle responsible for the synthesis of organic products and provides for intracellular storage and transport.

true

The smooth endoplasmic reticulum is the organelle that packages secretory products and renews and modifies plasmalemmae.

false

Small packages that move materials between cisternae in the Golgi apparatus are called lysosomes.

false

The mitochondrion is enclosed by a double membrane with numerous folds, or cristae, in the inner membrane; the fluid matrix of these organelles contains important metabolic enzymes.

true