Lecture 19: cell cycle and mitosis

Question 1

requirements for cell division

Answer 1

1. receipt of a signal to direct the cell to divide
2. DNA replication
3. DNA distribution (mitosis)
4. cytokinesis

Question 2

Which of the following are differences between cell division and mitosis?

Answer 2

cell division includes cytokinesis but mitosis only includes nuclear division

Question 3

identical chromatids

Answer 3

can be found in one chromosome

Question 4

Interphase has three distinct phases

Answer 4

• G1: cell growth and differentiation
• S: synthesis and replication of chromosomes
• G2: synthesis of molecules, other than DNA, needed for cell division
• G0: cells that never divide such as nerve cells

Question 5

mitosis

Answer 5

equal distribution of DNA into daughter cells

Question 6

5 phases of mitosis

Answer 6

• prophase
• prometaphase
• metaphase
• anaphase
• telophase

Question 7

Early Prophase

Answer 7

• chromosomes condense
• mitotic spindle grows out of the centrosomes
• kinetochore appears at the centromeres
• centrosomes migrate towards the poles

Question 8

prometaphase

Answer 8

• nuclear envelope disintegrates
• kinetochore appears at the centromere of each chromatid
• spindle fibers attach to the kinetochore

Question 9

metaphase

Answer 9

the centromere-kinetochore complexes align in the equator of the cell

Question 10

anaphase

Answer 10

• chromatid disjunction

- DNA molecules move toward opposite poles

Question 11

telophase

Answer 11

• nuclear envelope reforms
• spindle disappears
• DNA reverts to chromatin
• nucleolus reforms

Question 12

3 types of microtubules

Answer 12

• kinetochore: attach to each chromatid
• polar or non-kinetochore: overlap with each other
• astral: attach the centrosome to the cell pole

Question 13

Cytokinesis is different in animal and plant cells

Answer 13

• animal cells develop cleavage

- plant cells have a cell plate

Question 14

in a cell that is ready to divide, a homologous pair of chromosomes consists of

Answer 14

two chromosomes and four chromatids

Question 15

which of the following is true of. species that has a chromosome number of 2n=16

Answer 15

there are 8 homologous pairs

Question 16

what happens when cell cycle is out of control

Answer 16

-cancer grows from one original cancer cell

Question 17

cancer

Answer 17

arises from one cell that progresses too quickly through the cell cycle

Question 18

cyclins

Answer 18

family of. proteins that activate a specific kinase

Question 19

cyclin dependent kinase

Answer 19

activated by cyclin

Question 20

what is thee name of the process by which cancer cells break off tumors and spread to other parts of the body?

Answer 20

metastasis

Question 21

traits of cancer cells

Answer 21

1. released from the telomere shortening and apoptosis
2. undergo metastasis
3. accumulation of mutations

Question 22

telomerase

Answer 22

enzyme that catalyzes addition of telomere DNA sequences

-found in germ line cells, unicellular eukaryotes, and cancer cells

Question 23

metastasis

Answer 23

migration of cancer cells from primary tour to grow secondary tumors at distant locations in the body

Question 24

oncogene

Answer 24

codes for a protein that stimulates cell division

Question 25

tumor supressor gene

Answer 25

loss of function of protein removes inhibition of cell division

Question 26

viral oncogene

Answer 26

infection with a virus that has the oncogene can lead to loss of cell cycle control

Question 27

the incidence of cancer increases with age because

Answer 27

the longer we live, the more mutations accumulate