AP bio chapter 11 quiz

In some organisms, such as certain fungi and algae, cells undergo the cell cycle repeatedly without subsequently undergoing cytokinesis. What would result from this? See Concept 12.2 (Page) A. large cells containing many nuclei B. division of the organism into many cells, most lacking nuclei C. a rapid rate of gamete production D. inability to duplicate DNA E. a decrease in chromosome number

A

Is Autocrine signaling= A. B. C. D.

A

One difference between cancer cells and normal cells is that cancer cells A. continue to divide even when they are tightly packed together. B. are always in the M phase of the cell cycle. C. are unable to synthesize DNA. D. are arrested at the S phase of the cell cycle. E. cannot function properly because they are affected by density-dependent inhibition. Submit

A

The epinephrine signaling pathway plays a role in regulating glucose homeostasis in muscle cells. The signaling pathway is activated by the binding of epinephrine to the beta-2 adrenergic receptor. A simplified model of the epinephrine signaling pathway is represented in Figure 1. Which of the following outcomes will most likely result from the irreversible binding of GDP to the G protein? A. The intracellular concentration of glycogen will increase. B. The intracellular concentration of activated protein kinase A will increase. C. The intracellular concentration of cyclic AMP will increase. D. The intracellular concentration of glucose-1-phosphate will increase.

A

What effect does phosphorylating a protein have on that protein? A. Phosphorylation changes the shape of the protein, most often activating it. B. Phosphorylation adds energy to the protein, allowing it to form ATP from ADP and Pi. C. Phosphorylation may have no effect at all on the protein. D. Phosphorylation adds one or more phosphorus atoms to the protein, allowing it to perform a particular function.

A

Which of the following is true of benign tumors, but not malignant tumors? See Concept 12.3 (Page) A. They remain confined to their original site B. They can divide indefinitely if an adequate supply of nutrients is available. C. They have an unusual number of chromosomes. D. They are the result of the transformation of normal cells. E. They migrate from the initial site of transformation to other organs or tissues. Submit

A

Which of the following statements best describes microtubules? A. Microtubules are made up of subunits of tubulin, and are structures along which substances are transported in the cell. B. Microtubules are permanent cellular structures that help the cell to move from place to place. C. Microtubules are made up of subunits of actin, and function in muscle contraction and changes in cell shape. D. Microtubules are fibrous proteins coiled into cables that maintain cell shape and anchor the nucleus.

A

Which type of chemical signaling would be best for this situation= Some cancer cells release their own growth hormone rather than relying on growth hormones from the host organism or from other cells. This presents challenges to cancer researchers looking for ways to slow the growth of cancer cells ? A. Autocrine B. Direct content (Juxtacrine) C. Paracrine signaling D. Endocrine signaling

A

_____ is a carcinogen that promotes colon cancer. A. fat B. UV light C. estrogen D. a virus E. testosterone

A

Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue. Cell A is most likely in A. Prophase B. G1. C. G2. D. metaphase

B

Figure 1 shows a model of a signal transduction cascade, initiated by the binding of a ligand to the transmembrane receptor protein A A DNA mutation changes the shape of the extracellular domain of transmembrane receptor protein A produced by the cell. Which of the following predictions is the most likely consequence of the mutation? A. Production of activated molecule 1 will stop, but production of activated molecules 2 and 3 will continue. B. The molecule that normally binds to protein A will no longer attach, deactivating the cellular response. C. The molecule that normally binds to protein A will not enter the cell, thus no cellular response will occur. D. Since protein A is embedded in the membrane, the mutation will be silent and not affect the cellular response.

B

Glucocorticoids are steroid hormones that control cellular responses through several different signaling pathways. One of the signaling pathways involves the glucocorticoid receptor, an intracellular protein that is activated by binding to a glucocorticoid molecule. A simplified model of the glucocorticoid receptor signaling pathway is represented in Figure 1. Which of the following statements best predicts the effect of a mutation that results in a loss of the glucocorticoid receptor's ligand binding function? A. The transduction of the glucocorticoid signal across the plasma membrane will be blocked. B. The glucocorticoid receptor will remain associated with the accessory proteins. C. The rate of diffusion of glucocorticoid molecules into the cell will increase. D. The concentration of glucocorticoid receptors inside the nucleus will increase.

B

Is Direct Content (Juxtacrine) signaling= A. B. C. D.

B

The coagulation cascade controls blood clot formation in response to blood vessel injury. Thrombin is an enzyme that plays a key role in regulating the coagulation cascade. A simplified model of thrombin's role in regulating the coagulation cascade is represented in Figure 1. Figure 1. A simplified model of thrombin's role in regulating the coagulation cascade Argatroban is a competitive inhibitor of thrombin. Which of the following effects on the coagulation cascade is most likely to result from inhibiting thrombin activity with argatroban? A. The activation of clotting factors will be blocked. B. The rate of fibrin formation will decrease. C. Thrombin will be converted to prothrombin. D. The rate of blood clot formation will increase.

B

The decline of MPF activity at the end of mitosis is due to A. decreased synthesis of Cdk. B. the degradation of cyclin. C. the destruction of the protein kinase Cdk. D. the accumulation of cyclin. E. synthesis of DNA.

B

The epinephrine signaling pathway plays a role in regulating glucose homeostasis in muscle cells. The signaling pathway is activated by the binding of epinephrine to the beta-2 adrenergic receptor. A simplified model of the epinephrine signaling pathway is represented in Figure 1. Based on Figure 1, which of the following statements best describes the epinephrine signaling pathway? A. It involves the opening and closing of ion channels. B. In involves enzymes activating other enzymes. C. It involves changes in the expression of target genes. D. It involves protons moving down a concentration gradient.

B

What is the best description of the structure of a chromosome in the nucleus of a non-dividing cell? A. Two long DNA molecules wound around each other, with no proteins. B. One long DNA molecule, associated with many proteins. C. Two long DNA molecules wound around each other, associated with many proteins. D. One long DNA molecule, with no proteins.

B

Which type of chemical signaling would be best for plasmodesmata? A. Autocrine B. Direct content (Juxtacrine) C. Paracrine signaling D. Endocrine signaling

B

Why is it difficult to observe individual chromosomes with a light microscope during interphase? See Concept 12.1 (Page) A. They leave the nucleus and are dispersed to other parts of the cell. B. They have uncoiled to form long, thin strands. C. Sister chromatids do not pair up until division starts. D. The DNA has not been replicated yet. E. The spindle must move them to the metaphase plate before they become visible.

B

Which (multiple) of the cellular communication methods appear to be for signaling between cells that are in close proximity? A. Autocrine B. Direct content (Juxtacrine) C. Paracrine signaling D. Endocrine signaling

B and C

How can a protein outside the cell cause events to happen inside the cell? A. A protein can pass through the membrane and into the cell, causing signaling inside the cell. B. A protein outside the cell can cause the H+ ion concentration outside the cell to be higher, which allows substances to pass into the cell and transduce a signal. C. A protein outside the cell can bind to a receptor protein on the cell surface, causing it to change shape and sending a signal inside the cell. D. A protein outside the cell can phosphorylate a protein inside the cell, which transduces a signal and causes a response.

C

Is Paracrine signaling= A. B. C. D.

C

The epinephrine signaling pathway plays a role in regulating glucose homeostasis in muscle cells. The signaling pathway is activated by the binding of epinephrine to the beta-2 adrenergic receptor. A simplified model of the epinephrine signaling pathway is represented in Figure 1. Cyclic AMP phosphodiesterase is an enzyme that catalyzes the conversion of cyclic AMP to a different molecule. Which of the following best predicts the effect of inhibiting cyclic AMP phosphodiesterase in a muscle cell stimulated by epinephrine? A. The concentration of cyclic AMP will decrease because adenylyl cyclase will no longer be activated. B. The G protein will diffuse out of the cell because it will no longer bind to the plasma membrane. C. Phosphorylase kinase will remain active because protein kinase A will no longer be deactivated. D. Glycolysis will stop because epinephrine signaling will no longer stimulate glycogen breakdown.

C

The epinephrine signaling pathway plays a role in regulating glucose homeostasis in muscle cells. The signaling pathway is activated by the binding of epinephrine to the beta-2 adrenergic receptor. A simplified model of the epinephrine signaling pathway is represented in Figure 1. Which of the following statements best describes the role of adenylyl cyclase in the epinephrine signaling pathway? A. It converts a polymer to its monomer subunits. B. It moves substances across the plasma membrane. C. It accelerates the production of a second messenger. D. It transfers phosphate groups from ATP to protein substrates.

C

Which type of chemical signaling would be best for Quorum sensing? A. Autocrine B. Direct content (Juxtacrine) C. Paracrine signaling D. Endocrine signaling

C

Which type of chemical signaling would be best for this situation= NEUROTRANSMITTERS are ligands that are released from the axon of one nerve cell to the dendrite of another nerve cell. This helps to propagate the signal across several cells ? A. Autocrine B. Direct content (Juxtacrine) C. Paracrine signaling D. Endocrine signaling

C

In which of the cellular communication methods would a ligand (signaling molecule) need to have the longest "life"? A. Autocrine B. Direct content (Juxtacrine) C. Paracrine signaling D. Endocrine signaling

D

Is Endocrine signaling= A. B. C. D.

D

The epinephrine signaling pathway plays a role in regulating glucose homeostasis in muscle cells. The signaling pathway is activated by the binding of epinephrine to the beta-2 adrenergic receptor. A simplified model of the epinephrine signaling pathway is represented in Figure 1. A researcher claims that the epinephrine signaling pathway controls a catabolic process in muscle cells. Which of the following statements best helps justify the researcher's claim? A. Epinephrine is a signaling molecule that binds to a transmembrane protein. B. The G protein in the epinephrine signaling pathway consists of three different subunits. C. Phosphorylase kinase catalyzes the hydrolysis of ATP. D. Glycogen phosphorylase catalyzes the conversion of glycogen to glucose-1-phosphate.

D

Which of the cellular communication methods in Model 1 appear to be for signing between cells that are in close proximity? A. Autocrine B. Direct content (Juxtacrine) C. Paracrine signaling D. Endocrine signaling

D

Which of the following correctly matches a phase of the cell cycle with its description? See Concept 12.2 (Page) A. G2: cell division B. M: duplication of DNA C. S: immediately precedes cell division D. G1: follows cell division EAll of the above are correctly matched.

D

Which of the following is true of kinetochores? See Concept 12.2 (Page) A. They are located at the center of the centrosome; their function is to organize tubulin into elongated bundles called spindle fibers. B. They interdigitate at the cell's equator and then move apart, causing the cell to elongate. C. They attach to the ring of actin along the cytoplasmic surface of the plasma membrane, causing the actin to contract to form the cleavage furrow. D. They are sites at which microtubules attach to chromosomes. E. They are the primary centromere structures that maintain the attachment of the sister chromatids prior to mitosis. Submit

D

Which type of chemical signaling would be best for this situation= Cells in the human pancreas release insulin when blood sugar levels are elevated. The insulin signals cells in the liver to begin absorbing glucose and convert it to glycogen for storage ? A. Autocrine B. Direct content (Juxtacrine) C. Paracrine signaling D. Endocrine signaling

D

Which type of chemical signaling would be best for this situation= Cells in the pituitary gland produce thyroid stimulating hormone (TSH), which is received by cells in the thyroid. The arrival of TSH in the thyroid triggers production of several hormones, which then travel throughout the body to regulate metabolism ? A. Autocrine B. Direct content (Juxtacrine) C. Paracrine signaling D. Endocrine signaling

D

Which type of chemical signaling would be best for this situation= PHEROMONES released by a female gamete cell (egg) provide a pathway for the male gamete cell (sperm) to travel, increasing the possiblity of fertilization ? A. Autocrine B. Direct content (Juxtacrine) C. Paracrine signaling D. Endocrine signaling

D

A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain? See Concept 12.1 (Page) A. 46 B. 23 C. 46 or 92, depending on the portion of prophase examined D. 23 or 46, depending on the portion of prophase examined E. 92

E

Which of the following is found in binary fission but not in mitosis? See Concept 12.2 (Page) A. The result produces 2 nuclei. B. Following the process, a membrane separates the 2 copies. C. Replicated strands of DNA separate. D. Replication of DNA begins at an origin. E. Duplicated chromosomes attach to the plasma membrane.

E

Which of these is NOT a carcinogen? A. cigarette smoke B. testosterone C. UV light D. fat E. all of the above are carcinogens

E

requires hormones (example= insulin), will be in the target cell producing the hormone, requires blooc stream to transport hormone to some target cell matching EXACTLY to hormone

Endocrine signaling

direct contact (juxtacrine) examples= __________________________ =little openings between cells for communication

Gap Junction and Plasmodesmata

allows bacteria to commicate, work effectivly as a group, colony cordirates activities when the colony is big enough, expensive activities when big colony is split up, when small colony reproduce -works with paracrine signaling

Quorum sensing

- To coordinate the processes of life. Multicellulea rorganisms have billions of cells that must communicate to develop and survive. - Unicellular organisms must also communicate in order to locate nutrients and in some cases identify mating partners.

Why do cells need to communicate?

When you send a message to other cells but ALSO TO THEM SELVES and stimulating THEMSELVES

autocrine signaling

Means communication must occur when cells are in direct contact with each other

direct contact (juxtacrine)

cell communication types

direct contact (juxtacrine), synaptic signaling, paracrine signaling, autocrine signaling, and endocrine signaling

If blood sugar gets too low, _______________ ONLY targets LIVER and when picked up by liver, it breaks down glycogen, and puts it back into the blood stream

glucagon

According to Model 1, does the signal transduction pathwa occur inside or outside of a cell?

inside

when a Liver cell or body cell gets bathed in __________, it gets the glucose and stores it as GLYCOGEN

insulin

Is released to TARGET CELLS gets neighboring cells to reproduce creates new cells to make up for the dead ones

local regulator

Have memory once exposed for the rest of your life, so when exposed to the virus, pathogen, the memory cells remember how to defeat it

memory cells

chemicals that communicate across synaptic gap example= acetylcaine

neurotransmitter

Do all ligands for cellular communication have the same chemical structure (shape)?

no

Type of communication over ______short_____ distance, depends upon releasing LOCAL REGULATORS

paracrine signaling

occurs short distance, using neurotransmiters, in synaptic gap

synaptic signaling

Suggest some stimuli that might cause a cell to release a ligand and begin communication between cells.

temperature, smell, touch, and taste

***IMPORTANT QUESTION **WILL BE ON TEST Some hormones such as estrogen and testosterone are lipids and are therefore nonpolar. Explain why a receptor protein would not be needed for this type of ligand to activate a response in a cell

the receptor protein wouldn't be needed because it's steriods (nonpolar substance) can go through the membrane by itself and the receptor would be inside.