7. Cell Cycle

Question 1

What is the creation of 2 identical daughter cells?

Answer 1

Mitosis

Question 2

What is the order of phases in mitosis?

Answer 2

prophase–>Metaphase–>Anaphase–>Telophase

Question 3

Phase of growth and DNA replication?

Answer 3

Interphase ( G1, S phase, G2)

Question 4

Phase when chromosomes split + move to poles; cell division begins ( cleaveage furrow initiated)?

Answer 4

anaphase

Question 5

Phase when DNA compacts; nuclear envelope breaks down; MT’s begin formation of mitotic spindle?

Answer 5

prophase

Question 6

Phase when Nuclear envelope reappears with nucleus formation (nucleolus); cells pinch off?

Answer 6

Telophase

Question 7

Phase when chromosomes are in line; spindle complete; nuclear envelope gone

Answer 7

Metaphase

Question 8

What is cytokinesis?

Answer 8

cell division

Question 9

what is karyokinesis?

Answer 9

nuclear divison

Question 10

What is a chromosome?

Answer 10

single piece of DNA containing many genes; made up of 2 sister chromatids

Question 11

What is a chromatid?

Answer 11

1 of 2 identical copies of DNA ( 1 for each daughter cell)

Question 12

What is a Kinetochore?

Answer 12

The portion of the mitotic spindle that attaches to the centromere. It is a protein portion that binds DNA.

Question 13

What is a centromere?

Answer 13

the region of the chromosome that has unique DNA sequences, this region is bound by proteins that connect the two chromatids until the end of metaphase when they are separated.

Question 14

What is a centrosome?

Answer 14

Consist of 2 centrioles and is one type of MTOC that is typically located near the nucleus in non-dividing cells.

Question 15

What have 9 sets of microtubles arranged in triplets?

Answer 15

centrioles

Question 16

What are Cyclins? (generally)

Answer 16

group of proteins that regulate the cell cycle and cycle in level of expression during cell cycle.
they are also degraded during cell cyle

Question 17

A ______ is something that stimulates mitosis.

Answer 17

mitogen

Question 18

What creates maturation promoting factor (MPF)?

Answer 18

Cyclin B and CDK = MPF

Question 19

What does MPF involved with?

Answer 19

Phosphorylate lamins A & C –> Breakdown tetramer of nuclear lamina –> breakdown nuclear envelope

Question 20

What does Lamin B do?

Answer 20

Lamin B dimers are still connected to nuclear membrane fragments after dissociation by MPF, which will facilitate the reconstitution of the nuclear membrane

Question 21

What is the important role of cyclin function?

Answer 21

Different cyclins are present at different phases of mitosis thus regulating CDK activity at different phases.

Question 22

What is Cyclin B important for?

Answer 22

For the G2 to mitosis region and particularly through anaphase. Then its expression is abruptly shut off.

Question 23

CDK is ALWAYS present in the cell yet it is only active when ________.

Answer 23

cyclin is present

Question 24

What regulate or “brake” the cell cycle?

Answer 24

Cyclin dependent Kinase inhibitor (CKI) also called tumor suppressor genes.

Question 25

Radiation works bc it causes DNA damage to the targets cells that induces apoptosis. This induced apoptosis denpends on _____. Why is this a problem?

Answer 25

p53 function. Human cancers associated with mutations on both p53 alleles, which is fairly common, are particularly resistant to radio therapy.

Question 26

What destroys cyclins via built in ‘timebomb” where cyclins are tagged w/ ubiquitin for destruction in the cytosol?

Answer 26

proteosome

Question 27

________ is the very defined process of programmed cell death. it minimizes the release of the cell components into the surrounding tissue thus reducing inflammation and reducing further cell destruction.

Answer 27

apoptosis

Question 28

______ is the pathological process of accidental cell death due to trauma or disease. it can result in injury to surrounding tissue bc of the release of cell enzymes.

Answer 28

necrosis