Chapter 3 A&P review - online homework MK Lockwood PDF

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Chapter 3 A&P review

Chapter 3 A&P Which of the following is the main component of the cell membrane?

Phospholipids

Which of the following is a characteristic of the cell membrane?

Semipermeable

Which of the following is not a major function of proteins in the cell membrane?

forming the entire glycocalyx

What part of a cell membrane is usually in contact with the interstitial fluid?

phosphate heads of phospholipids

Which of the following is NOT one of the three major components of a typical eukaryotic cell?

ribosome

Which of the following acts as the digestive system of the cell, breaking down materials?

lysosome

Where in a typical eukaryotic cell would you expect to find genes?

in the DNA within the cell’s nucleus

Which of the following statements about cells is FALSE?

Cells join together to form organelles, which then form our organs and organ systems

What is the best description of the cell's plasma membrane?

ALL 1. It has a phospholipid bilayer. 2. It is its outermost boundary. 3. It regulates exchange with the exterior..

Channel proteins, as indicated by the arrow, are involved in

Transport

Chapter 3 A&P review

The backbone of the plasma membrane is a ______ bilayer

phospholipid

The smallest living unit within the human body is

the cell

The plasma membrane is composed of

a bilayer of phospholipids

The tails of a phospholipid molecule are

hydrophobic

Identify the role of cholesterol in the plasma membrane.

affects membrane permeability

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

ligands

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

Somatic

One function of the cytoskeleton is to provide

strength and integrity to the cell

rganelle is involved in the destruction of bacteria and old organelles and the liberation of enzymes?

lysosomes

nheritable mitochondrial disorders negatively affect which essential function directly?

the production of ATP

Actin is the subunit of ____

microfilaments

The organelles and the watery component of the cell together is called

cytoplasm

Chapter 3 A&P review

The watery component of the cytoplasm is called

cytosol

Components of the cytoskeleton may include all of the following except

microsomes

Which of the following descriptors regarding cytoplasm is false?

extracellular fluid contains more protein

Microfilaments

Tubulin is a

1. consist of the protein called actin 2. anchor the cytoskeleton to membrane proteins 3. with myosin, produce cell movement 4. control the consistency of cytoplasm protein that assembles into microtubules

Synthesis of lipids and glycogen takes place at the

smooth ER

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

Golgi apparatus

Organelles that break down fatty acids and hydrogen peroxide are

Peroxisomes

When activated, lysosomes function in Microtubules have which of the following functions?

digestion of materials

1. Molecular motors move along them 2. They form structural components of organelles 3. They provide a mechanism for changing the cell shape 4. They move chromosomes during cell division

Chapter 3 A&P review

Peroxisomes

1. are more abundant in cells with higher metabolic rates 2. contain enzymes that break down hydrogen peroxide 3. are produced from other peroxisomes 4. absorb and break down fatty acids, generating hydrogen peroxide in the process

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

form the mitotic spindle

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

modification of protein

Which of following properties of the cytoskeleton is incorrect?

made of cytobones

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

Membranous

____ are responsible for identifying and digesting damaged or denatured proteins

Proteasomes

Forensic scientists employed in crime fighting rely on DNA fingerprints. Which of the following statements does NOT verify the usability of DNA fingerprints in fighting crimes?

DNA fingerprints are unique to everyone, even identical twins

Chapter 3 A&P review

One of the characteristics of cancer cells is an increased need for protein production. Of the following choices, which organelle would be most closely associated with meeting this need?

Nucleoli

Chromosomes consist of histones bound to ____

DNA

As a red blood cell matures, it loses all of its DNA. As a result, it

cannot make new RNA

Chromosomes consist of ________ and ____

DNA; proteins

The control center for cellular operations is the

Nucleus

Most of a cell's DNA is located in its

nucleus

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

chromatin and histones

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

genes

Cilia are composed of microtubules. How are microtubules different from the other cytoskeletal filaments?

Microtubules are hollow tubes with a diameter of 25 nanometers and are composed of the protein tubulin.

What are cilia?

Cilia are numerous motile extensions of the plasma membrane that have an internal arrangement of nine pairs of microtubules surrounding a central microtubule pair (9+2 array)

Which of the following events occurs during transcription?

Chapter 3 A&P review

A molecule of RNA is formed based on the sequence of nucleotides in DNA. Which of the following is a correct statement about mRNA?

Thymine is replaced by which nitrogen base in RNA? mRNA moves from the nucleus to the cytoplasm following RNA processing. ribosomes in the cell cytoplasm

The site of translation is DNA Which one of the following does not play a role in translation? Which of the following does not occur during RNA processing?

mRNA attaches to the small subunit of a ribosome is transcribed into mRNA

DNA ______ "codon" The set of three nucleotides on the mRNA strand that are read by the ribosome is termed the What is a possible rationale for the difference between the DNA in chromatin and chromosome form?

1. loosely organized chromatin facilitates transcription 2. structure of chromatin allows DNA-binding proteins to access the DNA 3. Condensed chromatin keeps the DNA organized through cell division Messenger RNA

______ function(s) as the template during translation tRNA As each codon arrives at the active site of a ribosome, it attracts another molecule containing the anticodon. This molecule is called translation The process of protein formation directed by mRNA is called AGU The anticodon for the triplet UCA is

Chapter 3 A&P review

Uracil A gene is a set of specific instructions that

Which of the following solutions contains the most solute? indicates the sequence of amino acids in a protein molecule

Ribosomes are composed of protein and

rRNA

The enzyme ________ is required for the synthesis of mRNA

RNA polymerase

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

mRNA

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

tRNA

Which of the following best explains diffusion?

Which of the following is most likely to move through the cell membrane by facilitated diffusion? What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane?

movement of molecules from an area of high concentration to an area of low concentration

Na+

In facilitated diffusion, molecules only move with the aid of a protein in the membrane.

Which of the following is least likely to increase the rate of diffusion?

small concentration gradient

Which of the following is not required for osmosis to occur?

energy

Chapter 3 A&P review

hypertonic

In general, to maintain homeostasis the relationship between our intracellular and extracellular fluids should be which of the following? If a person is severely dehydrated, their extracellular fluids will become hypertonic to the intracellular fluid. What do you predict will happen to the person’s cells? The effectiveness of certain anesthetics depends in part on their lipid solubility. Why is this?

Some transport processes use transport proteins in the plasma membrane, but do not require ATP. This type of transport is known as isotonic to each other

The cells will lose water and shrink

The hydrophobic core of the phospholipid bilayer enables lipidsoluble substances to readily pass through the plasma membrane.

Pinocytosis is a form of ______ Endocytosis Water crosses the plasma membrane primarily by means of

simple diffusion

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

diffusion

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

hydrolysis of ATP.

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

Hypotonic

A primary active transport process is one in which

molecules move through transport proteins that have been activated by ATP

Chapter 3 A&P review

facilitated diffusion

The majority of water molecules moving across plasma membranes by osmosis do so via a process that is most similar to

Which of the following occurs during a single cycle of the sodiumpotassium exchange pump? facilitated diffusion

The sodium-potassium pump uses ATP to move sodium and potassium ions across the plasma membrane. This statement describes

primary active transport

A vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid. This statement describes

exocytosis

Passive movement of a solute by a carrier protein is called

facilitated diffusion

Carriers transport solutes across the plasma membrane by

changing shape as the solutes bind, causing the solutes to move across the membrane

What is the normal direction of calcium transport via the calcium pump?

out of the cell, against its concentration gradient

What is the energy source used by the calcium pump during its normal operation?

the hydrolysis of ATP

What concentration gradients are established and maintained by the sodium-potassium exchange pump?

high Na+ concentration in the extracellular fluid; high K+ concentration in the cytoplasm

Chapter 3 A&P review

Three Na+ ions are transported out of the cell The hormone epinephrine (adrenaline) increases the pumping rate of the sodium-potassium exchange pump in skeletal muscles. How would you expect this to affect the concentration of Na+ and K+ in the muscle cytoplasm?

The Na+ concentration would decrease and the K+ concentration would increase.

Which of the following best describes the difference between active and passive transport mechanisms?

Active mechanisms use energy to move solutes against their concentration gradients. Passive mechanism move solutes with their concentration gradients.

Facilitated diffusion differs from simple diffusion in that facilitated diffusion

requires a protein carrier

Facilitated diffusion differs from ordinary diffusion in that

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

All of the following membrane transport mechanisms are passive processes except

vesicular transport

The intake of materials from the extracellular fluid using vesicles is called

endocytosis

The principal cations in our body fluids are ________ and ____

sodium; potassium

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

sodium; potassium

Chapter 3 A&P review

Which of the following builds new strands of DNA?

In general, the cell cycle lasts about 24 hours in a normal dividing cell. However, mitosis occurs over 1–3 hours, much less than the other stages. Which of the following choices best explains why?

During mitosis, cells are nonfunctional

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

cations and anions

The potential difference across the cell membrane is known as

the membrane potential

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

potential difference

Before a cell can divide, what must occur during interphase?

Each chromatin fiber is duplicated in the nucleus

Which of the following lists, in correct order, the phases of interphase?

G1, S, and G2

Which of the following lists, in correct order, the phases of mitosis?

1. Prophase 2. Metaphase 3. Anaphase 4. Telophase (“I pee more after tea.”)

During which of the following phases does DNA replication occur?

Synthesis

During which of the following phases does chromatin condense and become chromosomes?

Prophase

Chapter 3 A&P review

DNA polymerase

Which statement best describes strand characteristics as it relates to DNA replication?

During DNA replication, which nucleotide will bind to an A nucleotide in the original or parental DNA strand? Which protein joins together the Okazaki fragments of DNA in the lagging strand? Which statement about DNA replication is FALSE?

During which phase of the cell cycle does DNA duplication, or replication, take place? When a double helix of DNA is replicated, two complete helices are formed. Together, these helices are called sister During which phase of mitosis do sister chromatids line up at the center of the cell? During which phase of mitosis do the sister chromatids move apart? During which phase of mitosis do nuclear envelopes and the nucleoli reappear?

During which phase of mitosis do the nuclear envelope and nucleoli disappear?

The leading strand is built continuously, and the lagging strand is built in pieces.

T

DNA ligase

DNA ligase adds nucleotides to the lagging strand.

Interphase

chromatids

Metaphase

Anaphase Telophase

Chapter 3 A&P review

Prophase

The genetically programmed death of cells is called

What is the name of the process by which the cytoplasm divides in two?

Cytokinesis

Which enzyme works simultaneously along both DNA strands to synthesize complementary strands of DNA?

DNA polymerase

Which phase of mitosis has chromosomes lining up in the center of the cell?

metaphase

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

form complementary sequences of DNA

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

interphase

When is DNA replicated?

interphase

A cell duplicates its chromosomes during the ________ phase

S

During mitosis, chromatids separate into daughter chromosomes in

Anaphase

Nuclear division of somatic cells is known as

Mitosis

Cells become more specialized by

turning off specific genes

The chromosomal structure that limits the number of cell divisions of a cell is the _____

telomere

Chapter 3 A&P review

apoptosis

Choose the correct statement about telomerases

Telomerases are enzymes that form telomeres

The cessation of telomerase activity as we age limits the number of times a cell can replicate. Current research on telomerases is particularly useful in the fight against cancer. Why is this so?

Cancer cells employ a mechanism that activates telomerases, which leads to uncontrolled cellular division.

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

Oncogene

A malignant neoplasm is often called a(n)

Cancer

There is a lot of talk about stem cells in the media. What is unique about these cells?

Stem cells are not fully differentiated.

What is the link between Parkinson’s disease and stem cell research?

Researchers have managed to generate induced pluripotent stem cells, which may differentiate into dopamine-producing neurons.

Differentiation requires __________ of particular genes to produce populations with __________ capabilities that form tissues

inactivation; limited

Chapter 3 A&P review...