Bio Exam 3 Launchpad

At the start of mitosis, how many centromeres are present in a human cell? 92 12 23 46

46

At the start of mitosis, how many sister chromatids are present in a human cell? 12 23 46 92

92

Replication of DNA in a eukaryote occurs during which phase of the cell cycle? G1 phase G2 phase S phase M phase

S phase

Cells differentiate into multiple tissue types because each tissue has its own unique DNA. False True

False

How would the loss of p53 activity affect a cell? CDK activity would not be appropriately regulated. All of these choices are correct. The G1/S checkpoint would not be functional. DNA damage could accumulate.

All of these choices are correct.

Which of the following statements concerning cyclin-dependent kinases (CDKs) is NOT true? CDKs are active, or "turned on," when complexed with cyclins. CDKs are enzymes that attach phosphate groups to other proteins. CDKs are inactive, or "turned off," in the presence of cyclins. CDKs are present throughout the cell cycle.

CDKs are inactive, or "turned off," in the presence of cyclins.

Which of the following is NOT true about cadherins? Cadherins are proteins that provide a pathway for molecules to move between cells. Cadherins are proteins involved in attachment of cells to the extracellular matrix. Cadherins are proteins involved in attachment of cells to neighboring cells. Cadherins are cell adhesion molecules found in cell junctions.

Cadherins are proteins that provide a pathway for molecules to move between cells.

If intermediate filaments were capable of dynamic instability, which of the following outcomes would be MOST likely? It is not possible to determine the outcome from the information given. Cilia would be altered. Cell-to-cell adhesion would be affected. Chromosome segregation would be affected. Cilia would collapse.

Cell-to-cell adhesion would be affected.

When nutrients are suboptimal for cell growth and division, the cell cycle arrests. At which stage of the cell cycle/checkpoint would you predict this arrest to occur? M checkpoint G2 checkpoint It is not possible to answer with the information given. G1 checkpoint G1, G2, and the M checkpoints

G1 checkpoint

The CORRECT sequence of steps in the eukaryotic cell cycle is: G0 → S phase → G1 → S phase → G2 → mitosis → cytokinesis. G0 → S phase → G1 → G2 → cytokinesis → mitosis. G0 → S phase → G1 → S phase → G2 → cytokinesis → mitosis. G1 → S phase → G2 → mitosis → cytokinesis. G1 → S phase → G2 → cytokinesis → mitosis.

G1 → S phase → G2 → mitosis → cytokinesis.

Which one of the following statements about intracellular transport is TRUE? Microtubules and intermediate filaments facilitate cellular movement, but microfilaments do not. Microtubules and microfilaments facilitate cellular movement, but intermediate filaments do not. Intermediate filaments, microfilaments, and microtubules all facilitate cellular movement of one kind or another. Intermediate filaments and microfilaments facilitate cellular movement, but microtubules do not.

Microtubules and microfilaments facilitate cellular movement, but intermediate filaments do not.

Which of the following statements about the strands of a newly replicated DNA molecule is CORRECT? The sugar-phosphate chains are conserved and new bases are inserted between them. One strand is new and the other is from the original molecule. Both strands contain some nucleotides from the original molecule. Both strands are made up of newly assembled nucleotides. The base pairs are conserved and new sugar-phosphate backbones are built up on them.

One strand is new and the other is from the original molecule.

How must spindle microtubules attach to chromosomes during prometaphase of meiosis I? Microtubules attach to the chiasma. Microtubules attach using their minus (slow assembling) ends. Spindle microtubules from one pole attach to one kinetochore, and spindle microtubules from the other pole attach to the other kinetochore in a pair of sister chromatids, just like in mitosis. Spindle microtubules from one pole must attach to both kinetochores in a pair of sister chromatids. Microtubules attach at the centrosomes.

Spindle microtubules from one pole must attach to both kinetochores in a pair of sister chromatids.

p53... Stops the cell cycle if DNA damage is present Does not impact cell division Directly promotes cell division if no DNA is present

Stops the cell cycle if DNA damage is present

Why are single-stranded binding proteins necessary for DNA replication? They direct the primase where to lay down the primer. They direct where replication will start. They provide the energy necessary to separate the two strands of DNA. None of the answer options is correct. They prevent the two parental strands from coming together again.

They prevent the two parental strands from coming together again.

Synthesis of nucleic acids always occurs in the 5' → 3' direction. True False

True

What is a cyclin? a protein that activates kinases a kinase a protein whose levels change with the cell cycle a protein that activates kinases and a protein whose levels change with the cell cycle

a protein that activates kinases and a protein whose levels change with the cell cycle

The microtubules that form the mitotic spindle extend out from the centrosome. Where would you expect to find the plus (fast assembling) end of a spindle microtubule? at the kinetochore at the centrosome away from the centrosome, at the kinetochore away from the centrosome

away from the centrosome, at the kinetochore

Mitosis MOST likely evolved from what process? the cell cycle cytokinesis meiosis binary fission

binary fission

The process of cell division in a prokaryotic cell is called: cytokinesis. binary fusion. binary fission. mitosis.

binary fission.

Which is the CORRECT order from lesser to greater complexity for the following? cells, organs, tissues cells, tissues, organs tissues, organs, cells organs, tissues, cells

cells, tissues, organs

A human cell with a total of 23 chromosomes is: haploid. polyploid. aneuploid. diploid.

haploid

Which of the following is a button-like point of attachment formed by the linking of integrins to intermediate filaments inside the cell and their binding to a protein of the extracellular matrix on the outside of the cell? hemidesmosome tight junction desmosome adherens junction

hemidesmosome

The fact that DNA replication occurs in virtually the same way in all organisms reflects: the laws of thermodynamics. its multiple origins in different lineages of organisms. its origin early in the history of life. the fact that mutations are generally harmful. the universal genetic code.

its origin early in the history of life.

Dynamic instability is the rapid assembly and disassembly of: both microfilaments and microtubules. microfilaments. intermediate filaments. microtubules.

microtubules

The division of genetic material in a eukaryotic cell is called: mitosis. genetic fission. replication. cytokinesis.

mitosis

The property of dynamic instability implies that the individual protein subunits of microtubules are held together by: noncovalent interactions. covalent bonds. All of these choices are correct. disulfide bonds.

noncovalent interactions.

Which of the following is NOT needed for DNA replication? None of the other answer options is correct. ribosomes nucleotides enzymes DNA

ribosomes

The two molecules of double-stranded DNA in a replicated chromosome are called: homologous chromosomes sister chromatids bivalent chromosomes non-sister chromatids

sister chromatids

A researcher is assessing the expression of a certain protein in cells. This protein appears as a "web" in the cytoplasm of cells. The protein is likely a component of: the extracellular matrix. All of these choices are correct. cell junctions. the cytoskeleton. the basal lamina.

the cytoskeleton.

Mitotic cell division is considered asexual because: the daughter cells receive DNA from one parent cell, and the daughter cells are genetically identical. this form of cell division is most similar to binary fission. the daughter cells receive DNA from one parent cell. the daughter cells are genetically identical.

the daughter cells receive DNA from one parent cell, and the daughter cells are genetically identical.

Which of the following is a mesh-like attachment between cells formed by binding of transmembrane proteins of one cell to the same protein type on the adjacent cell, preventing substances from passing between cells? hemidesmosome desmosome tight junction adherens junction

tight junction

What is the function of the centromere? to organize the microtubules to form a spindle to attach the DNA to the plasma membrane to attach the chromosome to the spindle to attach the sister chromatids to each other

to attach the sister chromatids to each other

What is the function of the enzyme DNA polymerase? to synthesize a strand of mRNA using mRNA as a template to synthesize a strand of DNA using DNA as a template to synthesize a strand of DNA using a polypeptide as a template to synthesize a strand of mRNA using DNA as a template to synthesize a polypeptide using DNA as a template

to synthesize a strand of DNA using DNA as a template

p53 is an example of a(n): proto-oncogene. cyclin-dependent kinase. tumor suppressor. oncogene.

tumor suppressor.

When we say that DNA replication is semiconservative, we mean that: None of the other answer options is correct. when DNA is replicated, each new double helix contains one parental strand and one newly synthesized daughter strand. parental DNA stays in the parent cell and daughter DNA ends up in the daughter cell. when DNA is replicated, one double helix contains both parental strands and one contains two newly synthesized daughter strands. only half of an organism's DNA is replicated during each cell division.

when DNA is replicated, each new double helix contains one parental strand and one newly synthesized daughter strand.