Bio 411 Ch 11

Another name for non-sister chromatids is: chiasmata. bivalents. diploids. homologous chromosomes.

homologous chromosomes

Homologous chromosomes separate from each other in: mitosis. meiosis I. meiosis II. They never separate from each other during any form of cell division.

meiosis I

asexual reproduction

occurs when offspring receive genetic material from a single parent

Crossing over occurs during which step in meiosis? Please choose the correct answer from the following choices, and then select the submit answer button. prophase II anaphase I prophase I metaphase I

prophase I

Which of the following is not a step in the process of binary fission? replication of DNA elongation of the cell rearrangement of the microtubule cytoskeleton formation of a new cell wall

rearrangement of the microtubule cytoskeleton

How do new cyclin proteins appear in the cytoplasm? They are recycled. They are made through protein synthesis. They are imported from outside the cell. All of these choices are correct.

they are made through protein synthesis

Why are the X and Y chromosomes not considered homologous? They do not carry the same set of genes, and mammalian males carry two very different sex chromosomes. They do not carry the same set of genes. They come from different parents. Mammalian males carry two very different chromosomes.

they do not carry the same set of genes, and mammalian males carry two very different sex chromosomes

How do CDKs promote cell division? They regulate the activity of cyclin. They bind to DNA. They cause cyclin levels to increase and decrease. They phosphorylate other proteins. They change the ability of microtubules to polymerize.

they phosphorylate other proteins

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

to attach the sister chromatids together

Some types of leukemia are the result of constitutively active (i.e., "always on") growth factor receptors.

true

what do plant cells form at the end of mitosis?

vesicles fuse to form a new cell wall called the cell plate

how does animal cytokinesis begin?

when the contractile ring forms against the inner face of the plasma membrane. the ring contracts, pinching the cytoplasm, and diving the cell in two

Mitosis daughter cells

2 daughter cells that are identical to each other and the parent cell

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

46

How many chromosomes do humans have?

46 chromosomes (23 pairs)

G0 phase

Cells are not actively dividing or preparing to divide. Cells still perform their normal functions. Time in this phase can range from days to over a year. Nerve and eye lens cells stay in this phase permanently

Polyploid

Condition in which an organism has extra sets of chromosomes

What happens in the S phase?

DNA is replicated

What are the two main phases of the cell cycle?

Interphase and M phase

Ploidy

The number of complete sets of chromosomes in a cell

Diploid

Two sets (pairs, like in human cells)

binary fission

a form of asexual reproduction that occurs when a cell replicates its DNA, increases in size, and divides into two daughter cells

contractile ring

a ring of actin filaments

metaphase

characterized by the alignment of the chromatid pairs in the center of the cell

Ploidy example:

Humans have 2 sets of 23 chromosomes 2N= 2x23 = 46 chromosomes

Why don't plant cells use a contractile ring to divide their daughter cells? Plant cells don't have an actin cytoskeleton. Plant cells don't form daughter cells. A contractile ring can't "pinch" a cell wall. Plant cells don't have plasma membranes.

a contractile ring can't "pinch" a cell wall

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

what do plant cells form during telophase?

a structure called a phragmoplast formed in the middle of the cell

The prokaryotic protein FtsZ is evolutionarily related to eukaryotic tubulin. What does this mean? The gene sequence for FtsZ is similar to tubulin. The amino acid sequence for FtsZ is similar to tubulin. The overall protein structure of FtsZ is similar to tubulin. The two proteins evolved from a common ancestral protein. All of these choices are correct.

all of these choices are correct

prophase

characterized by the appearance of condensed chromosomes in the nucleus Outside the nucleus, centrosomes duplicate, migrate to opposite ends of the cell, and produce microtubules that form the mitotic spindle.

telophase

characterized by the breakdown of the mitotic spindle and reformation of the nuclear envelope around each set of separated chromosomes the chromosomes decondense as the new nuclei form

anaphase

characterized by the splitting of centromeres, resulting in sister chromatid separation into individual chromosomes the spindle microtubules shorten, pulling the chromosomes to opposite ends of the cell

Muscle cells in the mammalian heart are multinucleate, meaning that multiple nuclei are present in the cytoplasm of a large cell. Predict what is different about the cell cycle in a muscle cell. S phase happens twice. Cytokinesis does not occur. M phase is inhibited. The G1 and G2 phases are extended.

cytokinesis does not occur

what follows telophase?

cytokinesis follows to divide the cell into two and differs between animals and plants

Which one of the following statements regarding the S cyclin-CDK complex is true? It ensures that DNA is not replicated multiple times. It is responsible for the degradation of nuclear membranes. It regulates the expression of histone proteins. It is regulated solely by the action of p53. It is responsible for the phosphorylation of nuclear proteins.

it ensures that DNA is not replicated multiple times

Why would a compound that interferes with bacterial cell wall synthesis be useful for treating a bacterial infection? It would limit the spread of the infection through cell division. It would prevent replication of DNA. It would prevent the cells from becoming larger. It would prevent replication of DNA, and it would limit the spread of the infection.

it would limit the spread of the infection through cell division

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

mitosis

Which of the following statements about viruses are true? Viruses contain multiple genes, and each of these genes is an oncogene. Viruses are a type of prokaryotic cell. Viruses are the root cause of most—if not all—cancers. Human cancers have not been associated with viruses. None of the answer options is correct.

none of the answer options are correct

A woman has her genome sequenced and finds that she carries a mutation in p53. Will she develop cancer? Possibly—this mutation may predispose her to developing certain types of cancer. Yes, she will certainly develop cancer given the role of p53 in the cell cycle. No, mutations in p53 do not contribute to cancer.

possibly- this mutation may predispose her to developing certain types of cancer

What are the phases in interphase?

G1 (gap 1 phase), S (synthesis phase), G2 (gap 2 phase)

Haploid

One set

When in the cell cycle would you find sister chromatids? S G2 G1 S and G2

S and G2

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

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

What happens in the G2 phase?

The cell prepares for mitosis and cytokinesis

What happens in the G1 phase?

The size and protein content increases to prepare for S phase. Many regulatory proteins are synthesized and activated including those that promote DNA replication

Recall the experiments of Rous and colleagues. If he had found that filtered cancer cell extract could not cause cancer when injected into healthy animals, what could he have deduced? Cancer may be caused by bacteria. An intact cancer cell is necessary to cause cancer. A large protein may cause cancer. All of these choices are correct.

all of these choices are correct

During what step in meiosis do the daughter cells become haploid? anaphase II anaphase I prophase II metaphase II

anaphase I

What would happen to the daughter cells if the G2 phase of the parent cell is shortened? The cells would not undergo cytokinesis. The cells would be missing chromosomes. The cells would be smaller than normal. The cells would be larger than normal.

the cells would be smaller than normal

sister chromatids:

the duplicated chromosomes that do not separate

Which of the following is not true regarding CDKs? They bind to cyclin. The levels of CDK change with the cell cycle. They function as a kinase. They function to control the cell cycle.

the levels of CDK change with the cell cycle

Synapsis is best described as: the exchange of genetic information between sister chromatids. the exchange of genetic information between non-sister chromatids. the alignment of non-sister chromatids at the metaphase plate. the pairing of homologous chromosomes in prophase I.

the pairing of homologous chromosomes in prophase I

cell division

the process of making more cells from an existing cell

List the steps of binary fission:

1. The circular DNA is attached by proteins to the inside of the plasma membrane 2. DNA replication begins at a site called the origin of replication and proceeds in opposite directions around the circle 3. The newly synthesized DNA is also attached to the membrane near the original DNA binding site

Which of the following statements is true regarding binary fission? Proteins only anchor the original circular genome to the plasma membrane; the copy produced by DNA replication is free-floating. In binary fission, cell division is typically asymmetrical, with one daughter cell appearing much smaller than the other. Tubulin, rather than FtsZ, is responsible for cell division during binary fission. DNA replication during binary fission is a bidirectional process, occurring in opposite directions. None of the answer options is correct.

DNA replication during binary fission is a bidirectional process, occurring in opposite directions

Which of the following is not a characteristic of meiotic cell division? Cell division results in the production of gametes. Daughter cells are genetically identical. Cell division requires two rounds of nuclear division. Cell division results in the formation of four daughter cells.

daughter cells are genetically identical