A & P Chapter 3 Homework

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

form complementary sequences of DNA.

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

form the mitotic spindle.

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

cytokinesis

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

diffusion

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

he blood osmotic pressure will increase.

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

hydrolysis of ATP.

Each of the following is true concerning mitochondria except

in glycolysis reaction pyruvate is produced from glucose inside the mitochondria.

Which of the following transport processes always requires metabolic energy?

vesicular transport

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

interphase

The plasma membrane includes all of the following except

peripheral proteins.

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

permeability

Channels

permit the passage of water and small solutes.

Which of the following organelles neutralizes toxic compound during cell metabolism?

peroxisome

A defense cell engulfing a bacterium illustrates

phagocytosis

Some white blood cells engulf bacteria and bring them into the cell. What is this process called? (Module 3.17D)

phagocytosis

Which structural component of the plasma membrane is mostly responsible for isolating a cell from its external environment? (Module 3.3A)

phospholipid

What is the purpose of motile cilia? (Module 3.4C)

propel material across the cell surface

mRNA is needed to synthesize ________ in the cytoplasm.

proteins

Identify the cell from which all the cells of your body are descendants. (Module 3.1B)

the fertilized ovum

The ER is connected to and continuous with what other organelle in the cell? (Module 3.5D)

the nuclear envelope around the nucleus

Which one of the following best defines differentiation?

the process of gradual structural and functional specialization of daughter cells

Facilitated diffusion differs from ordinary diffusion in that

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

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

the same number of chromosomes as the original cell.

What type of integral protein allows water and small ions to pass through the plasma membrane? (Module 3.3C)

channel protein

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

chromosomes.

Which of the following is an example of a nonmembranous organelle?

cilia

Which one of the following is an extension of plasma membrane?

cilia

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

codon

In Figure 3-1, which molecule is a combination of a sugar and a lipid?

1

What is translation? (Module 3.12A)

Taking the mRNA sequence and producing a protein.

Define cancer. (Module 3.21A)

An illness characterized by cell cycle mutations that produce malignant cells.

Define apoptosis. (Module 3.18B)

Apoptosis is genetically controlled cell death.

Water molecules and small ions enter a cell through

channels formed by integral proteins.

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

chromatin.

Cancer cells

may exhibit metastasis

Assume that the transport of a particular amino acid across the plasma membrane 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

facilitated diffusion

Most of a cell's ATP is produced within its mitochondria. What gas do mitochondria require to produce ATP, and what gas results? (Module 3.7B)

Oxygen is required to produce ATP, and carbon dioxide is released in the process.

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

facilitated diffusion.

Which cytoskeletal structure is found only in males? (Module 3.4D)

flagella

Microfilaments do not

form centrioles

Identify three different types of membranes based on permeability. (Module 3.13B)

freely permeable, selectively permeable, and impermeable

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

gene

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

genes.

Which term does not describe cells with abnormal growth and division?

germ cells

Describe the external environment of most of the body's cells. (Module 3.2D)

Our cells are surrounded by a watery extracellular fluid

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

hypertonic

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

hypotonic

Hemolysis may occur when a blood cell is placed into a(n) ________ solution.

hypotonic

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

hypotonic

A function of the glycocalyx is

lubrication of the cell surface.

Which cellular structure is responsible for cell autolysis?

lysosome

Which of the following organelles damages pathogens?

lysosomes

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

mRNA

Messenger RNA is vital to the cell because

mRNA can leave the nucleus and DNA cannot leave the nucleus.

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

matrix.

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

membranous

Which type of RNA links the genetic information in the nucleus with the cytoplasmic sites of protein synthesis? (Module 3.10D)

messenger RNA

List the three types of RNA involved in protein synthesis. (Module 3.10C)

messenger RNA, transfer RNA, and ribosomal RNA

What is the term for mRNA?

messenger ribonucleic acid

Endocytosis is a

method for transporting substances into the cell.

Terminal web is a layer of ________ just inside plasma membrane at the exposed surface of the cell.

microfilaments

List the three basic components of the cytoskeleton. (Module 3.4A)

microfilaments, intermediate filaments, and microtubules

Which cytoskeletal component is common to both centrioles and cilia? (Module 3.4B)

microtubules

Providing strength and moving materials within the cell is a function of the filaments and

microtubules.

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

microtubules.

Which of the following is an example of a membranous organelle?

mitochondria

Which of the following organelles produces 95% of cell ATP?

mitochondria

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

mitochondria.

DNA replication occurs during what two cellular processes? (Module 3.19D)

mitosis and meiosis

Nuclear division in somatic cells is known as

mitosis.

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

mitosis.

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

modification of protein

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

more carbon dioxide will diffuse out of the blood in the lungs.

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

multiple enzymes; three types of RNA

An alternate term for tumor is

neoplasm

The nucleus is surrounded by the

nuclear envelope.

Transfer of mRNA from the nucleus to the cytosol occurs through

nuclear pores.

The components of ribosomes are synthesized by

nucleoli

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

nucleolus

Histones are found in

nucleosomes

Which organelle is visible under light microscope?

nucleus

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

edited to remove introns and transported into the cytoplasm.

Which organelle synthesizes lipids and carbohydrates?

smooth endoplasmic reticulum

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

sodium; potassium

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

sodium; potassium

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

stem

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?

steroid hormones

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

stiffening the membrane

Describe the functions of the cytoskeleton. (Module 3.2C)

strengthens and supports the cells and enables movement of cellular

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

tRNA

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

tRNA

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

telophase

When a protein-releasing factor recognize a stop codon, the process is called

termination

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

the cells will swell.

What two factors limit the rate of facilitated diffusion across a plasma membrane? (Module 3.16B)

the concentration gradient of the substance and the number of carrier proteins

Distinguish between passive and active processes of membrane passage. (Module 3.13C)

Passive processes do not need ATP and active processes do need ATP.

How many nuclei do most body cells contain? (Module 3.8B)

1

How many chromosomes are contained within a typical somatic cell? (Module 3.9C)

23 pairs

In Figure 3-1, which structure is water most likely to pass through?

3

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 trans face. 5. Vesicles arrive at the cis face. 6. Enzymes modify arriving proteins and glycoproteins. What is the proper order for these steps?

3, 5, 6, 1, 4, 2

In Figure 3-1, which structure is related to glycocalyx?

4

In Figure 3-1, microfilaments are labeled with which number?

5

In Figure 3-1, which molecule is the peripheral protein?

7

What is a chromatid, and how many are present during normal mitosis in a human cell? (Module 3.20B)

A chromatid is a copy of a duplicated chromosome, and 92 are present.

What is a gene? (Module 3.10A)

A gene is a portion of a DNA strand that functions as a hereditary unit and codes for a specific protein.

What is a benign tumor? (Module 3.21B)

A mass produced by abnormal growth and division of cells that remains within the original tissue and does not spread.

The anticodon for the triplet UCA is

AGU

The endoplasmic reticulum is not responsible for ________ synthesis

ATP

Which of the following is not part of cell theory?

All cells differentiate into specialized cell types.

The nucleotide sequence of three mRNA codons is AUU-GCA-CUA. What is the complementary anticodon sequence for the second codon? (Module 3.12B)

CGU

What do the transport processes of facilitated diffusion and active transport have in common? (Module 3.16C)

Carrier proteins are used to transport materials in both processes.

When does cell division begin and end? (Module 3.18C)

Cell division begins at mitosis and ends at cytokinesis.

Distinguish between the cytoplasm and cytosol. (Module 3.2A)

Cytoplasm is the material between the plasma membrane and the nuclear membrane; cytosol is the fluid portion of the cytoplasm.

What molecule in the nucleus contains instructions for making proteins? (Module 3.9B)

DNA

What enzymes must be present for DNA replication to proceed normally? (Module 3.19C)

DNA polymerase, DNA ligase, and DNA helicase

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

DNA replication

Chromosomes consist of ________ and ________.

DNA; proteins

Describe endocytosis. (Module 3.17A)

Endocytosis occurs when a vesicle forms at the plasma membrane, encloses a large volume of extracellular fluid and contents, and then moves into the cytoplasm

________ is when a vesicle fuses to the plasma membrane and discharges its contents to the extracellular environment.

Exocytosis

Describe exocytosis. (Module 3.17C)

Exocytosis occurs when a vesicle forms inside the cell, encloses a large volume of intracellular fluid and contents, and then fuses with the plasma membrane to release it outside the cell.

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

G0 phase

A cell is actively manufacturing enough organelles to serve two functional cells. This cell is probably in what phase of interphase? (Module 3.19B)

G1

How is genetic information coded in the cell? (Module 3.8A)

Genetic information is coded by the sequence of nucleotides in DNA.

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

Golgi apparatus.

Stacks of cisternae that store, alter, and package synthesized products are called

Golgi apparatus.

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?

Hydrostatic Pressure Higher in Side 1

Describe the process of carrier-mediated transport. (Module 3.16A)

In carrier-mediated transport, integral membrane proteins bind ions or molecules and transport them across the membrane.

Which of the following is correct regarding cytoplasm?

It contains cytosol and organelles

Why is the genetic code described as a triplet code? (Module 3.10B)

It is described as a triplet code because a sequence of three nitrogenous bases specifies the identity of a specific amino acid.

Which of following properties of the cytoskeleton is false?

It is made of cytobones

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

It sends transport vesicles to the RER

What is transcription? (Module 3.11A)

Making an RNA strand from the DNA template.

________ increase surface area to facilitate absorption of extracellular materials.

Microvilli

Define mitosis, and list its four stages. (Module 3.20A)

Mitosis is the division of a cell into two identical daughter cells. The four stages are prophase, metaphase, anaphase, and telophase.

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

Mutations

Describe the immediate cellular destinations of newly synthesized proteins from free ribosomes and fixed ribosomes. (Module 3.5A)

Newly synthesized proteins from free ribosomes enter the cytosol, and newly synthesized proteins from fixed ribosomes go to enter the ER.

The enzyme ________ is required for the synthesis of mRNA.

RNA polymerase

A cell duplicates its chromosomes during the ________ phase.

S

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

Somatic

What characteristic of phospholipids accounts for their packing into a double layer? (Module 3.3D)

That they are amphipathic, containing a hydrophobic end and a hydrophilic end.

List the three major functions of the Golgi apparatus. (Module 3.6A)

The Golgi apparatus (1) renews or modifies the plasma membrane, (2) modifies and packages cellular secretions, and (3) packages special enzymes within vesicles (lysosomes) for use within the cell.

What does the presence of many mitochondria imply about a cell's energy requirements? (Module 3.7C)

The cell has high energy demand.

Contrast the effects of a hypotonic solution and a hypertonic solution on a red blood cell. (Module 3.15C)

The hypotonic solution would cause the RBC to swell and it may burst (hemolysis), and the hypertonic solution would cause the RBC to shrink (crenation).

Why do certain cells in the ovaries and testes contain large amounts of SER? (Module 3.5C)

The ovaries and testes produce large amounts of steroid hormones which are lipid based.

Define diffusion. (Module 3.14A)

The passive movement of molecules from an area of higher concentration to an area of lower concentration until equilibrium is achieved

Describe osmosis. (Module 3.15A)

The passive movement of water across a selectively permeable membrane from a solution with a lower solute concentration to a solution with a higher solute concentration.

Define metastasis. (Module 3.21C)

The spread of cancer cells beyond the original tissue, leading to secondary tumors.

Name the substrates and product in the enzymatic reaction catalyzed by RNA polymerase. (Module 3.11C)

The substrates are RNA nucleotides, and the product is a strand of mRNA.

Microtubules do not have which of the following functions?

They stiffen microvilli.

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

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

What process would be affected if a cell could not synthesize the enzyme RNA polymerase? (Module 3.11D)

Transcription of RNA from DNA.

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

UAG.

What kinds of molecules are involved in both active and passive processes of membrane passage? (Module 3.13D)

carrier proteins

During digestion, the concentration of hydrogen ions (H+) in the stomach contents increases to many times that in cells lining the stomach. Which transport process could be responsible? (Module 3.16D)

active transport

Which of the following membrane transport mechanisms is not directly a passive process?

active transport

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

active transport.

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

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

The cylindrical shaped organelle with nine groups of microtubule triplets is called

centrioles.

During mitosis, chromatids separate into daughter chromosomes during

anaphase

Microfilaments

anchor the cytoskeleton to the plasma membrane.

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

anticodon

The genetically programmed death of cells is called

apoptosis.

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

are stem cells.

Anchoring proteins

attach the plasma membrane to other structures in the cell.

The start of each gene begins with a(n) ________ segment.

control

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

crenation; hemolysis

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

diffusion

What do lysosomes contain? (Module 3.6B)

digestive enzymes

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

endocytosis

Two types of vesicular transport are

endocytosis and exocytosis.

Membrane-bound proteins that use metabolic energy to move ions across the plasma membrane are called

ion pumps.

All of the following can be true about osmotic pressure except

it forces solutes toward the higher water concentration.

All of the following are characteristics of nucleus, except

it packages and sorts products.

Ribosomes are composed of protein and

rRNA

Mitosis is to somatic cells as meiosis is to ________ cells.

reproductive

What is the term for rRNA?

ribosomal ribonucleic acid

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

rough endoplasmic reticulum

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

rough endoplasmic reticulum

Which of the following organelles has ribosomes bound to its membrane?

rough endoplasmic reticulum

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

selectively permeable

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

serve as cell nutrients

Synthesis of lipids and glycogen takes place at the

smooth ER.

All of the following are correct about integral protein, except

they are bound to the inner surface of plasma membrane

The process of forming mRNA is called

transcription.

What is the term for tRNA?

transfer ribonucleic acid