Exam 4 (Chapter 9 and 10)

A somatic cell from a garden pea normally contains 14 chromosomes.How many sister chromatids would that cell contain during G1 of the cell cycle? a. 0 b. 7 c. 14 d. 28

a. 0

A somatic cell from a corn plantnormally contains 20 chromosomes. How many sister chromatids would that cell contain during G2 of the cell cycle? a. 40 b. 10 c. 0 d. 20

a. 40

The two basic mechanisms that can inactivate RTK's are which of the following? a. Dephosphorylation b. Phosphorylation c. Internalization d. Externalization

a. Dephosphorylation c. Internalization

One cell sends second messengers to another cell through gap junctions. What type of signaling would this be considered? a. Direct contact b. Autocrine c. Endocrine d. Paracrine e. Synaptic

a. Direct contact

Interphase is made up of what stages of the cell cycle? a. G 1 + G 2 + S b. cytokinesis + mitosis c. S + cytokinesis d. G 0 + G 1 + G 2 e. prophase + metaphase + anaphase + telophase

a. G 1 + G 2 + S

At what checkpoint(s) does the cell arrest in response toDNA damage? a. G 1/S and G 2/M b. G 1/S c. G 2/M d. G 2/M and spindle e. spindle

a. G 1/S and G 2/M

Which of the three types of membrane receptors acts indirectly via a "helper" molecule? a. G protein-coupled receptors b. Enzymatic receptors c. Channel-linked receptors d. None of the options are correct

a. G protein-coupled receptors

Cell surface or membrane receptors bind this type of ligand. a. Hydrophilic b. Both hydrophobic and hydrophilic c. Neither hydrophobic or hydrophilic d. Hydrophobic

a. Hydrophilic

A signaling molecule is known as which of the following? a. Ligand b. Ligase c. Protein d. Intercellular protein

a. Ligand

A duplicate copy of all of the hereditary information contained in the nucleus of eukaryotic cellsis made during what stage of the cell cycle? a. S b. G 1 c. Cytokinesis d. G 2 e. Mitosis

a. S

Which of the following are examples of paracrine signaling? Select all that apply a. Signals between immune cells b. Signals conveyed through hormones, such as insulin c. Signals that coordinate the activities of clusters of cells during development d. Signals in the synapses of nerve cells, but only when the target cell is a muscle cell

a. Signals between immune cells c. Signals that coordinate the activities of clusters of cells during development

These structures are held together by cohesin: a. Sister chromatids b. Homologous chromosomes c. Nucleosomes d. Solenoids

a. Sister chromatids

Estimates are that p53 is mutated in 50% of all human cancers. If the gene that encodes p53 is mutated such that p53 is non-functional, what processes would be affected? Check all that apply. a. The ability to stimulate cell death processes if the cell is irreparably damaged. b. The ability to halt the cell cycle in response to DNA damage. c. The ability to halt the cell cycle in response to the chromosomes not properly aligning on the metaphase plate. d. The ability to repair DNA damage. e. The ability to activate Cdks.

a. The ability to stimulate cell death processes if the cell is irreparably damaged. b. The ability to halt the cell cycle in response to DNA damage. d. The ability to repair DNA damage.

The point of constriction on chromosomes thatcontains certain repeated DNA sequences that bind specific proteins is called: a. The centromere b. The kinetochore c. The centrosome d. The cohesin complex e. The centriole

a. The centromere

Using a specific chemical, a cell biologist has blocked one type of channel-linked receptorin a lab rat's liver tissue. What was the likely mechanism of the chemical she used? a. The chemical prohibits binding of a ligand to the receptor. b. The chemical causes ions to move in the opposite direction of the ion gradient. c. The chemical prohibits second messenger signaling. d. The chemical prohibits ions from entering the cell via active transport.

a. The chemical prohibits binding of a ligand to the receptor.

Which of the following are the two typical locations of intracellular receptors in the cell? a. The cytoplasm b. The mitochondria c. The nucleus d. The rough ER

a. The cytoplasm c. The nucleus

Binary fission in bacterial cells and mitosis in eukaryotic cells produce genetically identical cells. a. True b. False

a. True

The function of adenylyl cyclase is to: a. catalyze the conversion of ATP to cAMP. b. cleave PIP 2 into DAG and IP3. c. stimulate the release of calcium from the endoplasmic reticulum. d. directly activate protein kinase A (PKA).

a. catalyze the conversion of ATP to cAMP.

What time point represents G2? a. 2 b. 3 c. 1 d. 4

b. 3

When bound to ligand, this type of receptor changes conformation to allow ions to move down their concentration gradient across the membrane: a. G protein-coupled receptor b. Channel-linked receptor c. Steroid hormone receptor d. Enzymatic receptor

b. Channel-linked receptor

The progress of the eukaryoticcell cycleis regulated primarily by what proteins? a. Histone proteins b. Cyclins c. FtsZ d. Condensins

b. Cyclins

The portion of the cell cycle when the cell is growing and does not contain a replicated genome is referred to as: a. S b. G 1 c. Cytokinesis d. Mitosis e. G 2

b. G 1

Which of the following are the three subclasses of membrane receptors? a. Hormone receptors b. G protein-coupled receptors c. Channel-linked receptors d. Neuroreceptors e. Enzymatic receptors

b. G protein-coupled receptors c. Channel-linked receptors e. Enzymatic receptors

What proteins can bind GTP and GDP? a. G protein-coupled receptors b. G proteins c. Chemically-gated ion channels d. Enzymatic receptors

b. G proteins

Intracellular receptors bind this type of ligand. a. Hydrophilic b. Hydrophobic c. Both hydrophobic and hydrophilic d. Neither hydrophobic or hydrophilic

b. Hydrophobic

What isthe portion of the cell cycle during which the chromosomes are invisible under the light microscope because they are not yet condensed? a. Telophase b. Interphase c. Prophase d. Anaphase e. Metaphase

b. Interphase

These molecules can directly convert extracellular signals into intracellular signals. a. Adapter proteins b. Membrane receptors c. Scaffolds d. G proteins e. Second messengers

b. Membrane receptors

The bacterial genome consist of a single loop of DNA located in which of the following regions of the cell? a. Nucleus b. Nucleoid c. Nucleolus d. Nucleosome

b. Nucleoid

What type of cellular communication is depicted on this diagram? a. Endocrine signaling b. Paracrine signaling c. Synaptic signaling d. Direct contact

b. Paracrine signaling

Choose the four general types of cell communication. a. Nerve impulses b. Paracrine signaling c. Endocrine signaling d. Direct contact e. Signal transduction f. Synaptic signaling

b. Paracrine signaling c. Endocrine signaling d. Direct contact f. Synaptic signaling

What signaling pathway commonly makes use of a G protein to transduce the signal? a. Channel-linked receptor pathways b. Receptor tyrosine kinase pathways c. Steroid hormone receptor pathways

b. Receptor tyrosine kinase pathways

G protein-coupled receptors are the largest family of cell surface receptors. Each receptor passes through the plasma membrane how many times? a. Five times b. Seven times c. Once d. Three times

b. Seven times

What is the function of a protein kinase? a. To remove phosphate groups from proteins b. To add phosphate groups onto proteins c. To phosphorylate GDP to generate GTP d. To cleave membrane phospholipids

b. To add phosphate groups onto proteins

Adenylyl cyclase is an effector protein that produces the second messenger __________. a. ATP b. cAMP c. Ras d. GDP

b. cAMP

Cdks are enzymes which regulate proteins within the cell cycle via __. a. methylation b. phosphorylation c. degradation d. ubiquitylation

b. phosphorylation

Some enzymatic receptors and most G protein-coupled receptors transmit the signal into the cytoplasmby utilizing other substances within the cytoplasm that are referred to as: a. first messengers. b. second messengers. c. intracellular receptors. d. genes.

b. second messengers.

A small number of cell surface receptors can ultimately generate a large intracellular response due to activation of kinase cascades. This is referred to as: a. signal activation. b. signal amplification. c. signal transduction. d. signal dampening.

b. signal amplification.

The protein Sonic Hedgehog (SHH) plays a role in specifying the identity of digits (such as fingers and toes) in mammals. Several digits arise directly from cells that both express and respond to secreted SHH. What type of signaling would this be considered? a. Paracrine b. Synaptic c. Autocrine d. Direct contact e. Endocrine

c. Autocrine

How are receptor tyrosine kinases and steroid hormone receptors similar? a. Both are transmembrane proteins with a single transmembrane domain b. Both are activated by autophosphorylation c. Both have a site for binding ligand d. Both have a DNA-binding domain

c. Both have a site for binding ligand

What enzymes control the progression of cells through the cell cycle checkpoints? a. Checkpoint phosphatases b. MPFs c. Cdks d. MAP kinases

c. Cdks

The stage of the cell cycle during which the cytoplasm divides to form two cells is called: a. G 1 b. S c. Cytokinesis d. Mitosis e. G 2

c. Cytokinesis

Where do second messengers relay signals? a. They do not relay signals b. Outside the cell c. Inside the cell d. To the cell surface receptor

c. Inside the cell

This is the stage of mitosis characterized by the alignment of the chromosomes in a ring along the inner circumference of the cell: a. Interphase b. Telophase c. Metaphase d. Prophase

c. Metaphase

Signaling molecules that stimulate a cell to divide are called which of the following? a. Kinases b. Nitric oxide c. Mitogens d. Mutagens

c. Mitogens

The accommodation of the very long DNA strands that are part of a chromosomeinto the limited space of the nucleus is achieved by coiling the DNAaround beads of histones into repeating subunits. These DNA-wrapped histones are called: a. Solenoids b. Rosettes c. Nucleosomes d. Chromatin loops

c. Nucleosomes

The addition or removal of which group is a major source of control for protein function during signal transduction? a. Amino b. Acetyl c. Phosphate d. Carboxyl

c. Phosphate

During this stage of mitosis, the chromosomes become attached to the spindle at their kinetochores. a. Metaphase b. Prophase c. Prometaphase d. Telophase e. Anaphase

c. Prometaphase

Identify the type of protein encoded by the cdc2 gene. a. Isomerase b. Oxidase c. Protein kinase d. Dehydrogenase

c. Protein kinase

In bacterial cell division, the cell divides into two nearly equal halves. This process is referred to as: a. meiosis b. cytokinesis c. binary fission d. mitosis e. fusion

c. binary fission

If necessary (e.g., if DNA is damaged), the cell cycle can be arrested at specific points called _________. a. CDKs b. cyclins c. checkpoints d. phases

c. checkpoints

In prophase, ribosomal RNA synthesis stops when the chromosomes condense, and as a result: a. the nuclear envelope reforms. b. the chromosomes line up at the equator of the cell. c. the nucleolus disappears. d. the chromosomes lengthen.

c. the nucleolus disappears.

If a cell has 32 chromosomes prior to S and undergoes mitosis followed by cytokinesis, each new daughter cell will have how many chromosomes? a. 16 b. 64 c. 8 d. 32

d. 32

The stage of mitosis characterized by the physical separation of sister chromatids is called: a. Telophase b. Metaphase c. Prometaphase d. Anaphase

d. Anaphase

Eukaryotic chromosomes are composed of a complex of 60% protein and 40% DNA. This complex is referred to as: a. The kinetochore b. The histone complex c. Cohesin d. Chromatin

d. Chromatin

The physical distribution of cytoplasmic material into the two daughter cells in plant cellsis referred to as: a. The gap phase b. Interphase c. Binary fission d. Cytokinesis

d. Cytokinesis

This stage of the cell cycle is characterized by growth and it contains a checkpoint to verify that all of the DNA has been replicated prior to mitosis. a. Cytokinesis b. G 1 c. S d. G 2 e. Mitosis

d. G 2

The cell surface receptors that can act onlyindirectly on plasma membrane-bound enzymes or ion channels are called: a. second messenger receptors. b. gated ion channels. c. enzymatic receptors. d. G protein-coupled receptors.

d. G protein-coupled receptors.

While preparing to divide, the cell grows and copies its chromosomes during which stage? a. Telophase b. Anaphase c. Metaphase d. Interphase e. Cytokinesis

d. Interphase

During what stages of the cell cycle are sister chromatids bound together by cohesin? a. G 1, S b. S, G 2 c. G 1, S, G 2 d. S, G 2, prophase, metaphase e. S, G 2, prophase, metaphase, anaphase, telophase

d. S, G 2, prophase, metaphase

Before cell division of somatic cells, each chromosome must be replicated. After replication, the resulting two parts of each chromosome are held together by cohesin at the centromere. These two parts are referred to as: a. Daughter chromosomes b. Kinetochores c. Genes d. Sister chromatids e. Homologous chromosomes

d. Sister chromatids

This stage of mitosis is characterized by the disassembly of spindle apparatus, the reestablishment of the nuclear membrane, and the decondensation of the chromosomes: a. Anaphase b. Metaphase c. Prometaphase d. Telophase

d. Telophase

What stage of mitosisis essentially the reverse of prophase? a. Prometaphase b. Cytokinesis c. Anaphase d. Telophase e. Metaphase

d. Telophase

If a chromosome contains a mutation such that it cannot bind to the kinetochore complex, what would be the consequence? a. That chromosome would not be able to be replicated. b. That chromosome would not be able to condense. c. That chromosome would not be able to interact with histone proteins. d. That chromosome would not be able to bind to the mitotic spindle.

d. That chromosome would not be able to bind to the mitotic spindle.

What property defines most ligands for intracellular receptors? a. They are hydrophilic b. They are large molecules c. They are molecules that can perform significant hydrogen bonding interactions with water d. They are lipid-soluble

d. They are lipid-soluble

Plant cells typically achieve cytokinesis by: a. forming a cleavage furrow that pinches the cell into two. b. binary fission. c. chromosome elongation. d. forming a cell plate across the middle of the cell. e. chromosome condensation.

d. forming a cell plate across the middle of the cell.

Animal cells typically achieve cytokinesis by: a. chromosome condensation. b. chromosome elongation. c. forming a cell plate across the middle of the cell. d. forming a cleavage furrow that pinches the cell into two. e. binary fission.

d. forming a cleavage furrow that pinches the cell into two.

Small molecules or ions that relay signals inside the cytoplasm are called second __________. a. effectors b. carriers c. activators d. messengers

d. messengers

This protein or protein complexfunctions in the cell to stop cell division if the cell has experienced extensive DNA damage: a. FtsZ b. APC/C c. Condensin d. p53

d. p53

What is the sequence of events in a typical eukaryotic cell cycle? a. S to G1 to G2 to mitosis to cytokinesis b. G1 to S to G2 to cytokinesis to mitosis c. G1 to G2 to S to mitosis to cytokinesis d. G1 to G2 to mitosis to S to cytokinesis e. G1 to S to G2 to mitosis to cytokinesis

e. G1 to S to G2 to mitosis to cytokinesis

In response to injury, cell fragments called platelets get activated to induce clotting. Activated platelets release factors that can in turn bind to specific membrane receptors on nearby cells. What type of signaling would this be considered? a. Autocrine b. Direct contact c. Synaptic d. Endocrine e. Paracrine

e. Paracrine

In synaptic signaling, neurotransmitters are released into a space that is referred to as a: a. paracrine space. b. plasmodesmata. c. neuron junction. d. gap junction. e. chemical synapse.

e. chemical synapse.