CHAPTER 12: Cell Cycle (Mitosis)

Question 1

what occurs during interphase?

Answer 1

1. the cell grows in preparation for cell division.
2. chromosomes are duplicated with DNA copied precisely.

Question 2

what percent is interphase of the entire cell cycle?

Answer 2

90%

Question 3

what are the three phases of interphase?

Answer 3

G1, S, and G2

Question 4

what occurs during S phase?

Answer 4

chromosomes are duplicated

Question 5

what is mitosis?

Answer 5

division of genetic material in nucleus.

Question 6

what are the stages of mitosis?

Answer 6

prophase, prometaphase, metaphase, anaphase, and telophase

Question 7

what is cell division?

Answer 7

the reproduction of cells

Question 8

what occurs during cytokinesis (during m phase)

Answer 8

the cell divides into 2 daughter cells that are genetically identical to each other and parent cell.

Question 9

what is the one thing that distinguishes living things from nonliving things?

Answer 9

the ability of organisms to produce more of their own kind.

Question 10

single-celled organisms give rise to new organisms through what process?

Answer 10

cell division.

Question 11

what do multicellular eukaryotes undergo?

Answer 11

embryonic development

Question 12

what are sister chromatids?

Answer 12

joined copies of the original chromosome

Question 13

what is the centromere?

Answer 13

the narrow “waist” of the duplicated chromosome

Question 14

when chromatids are separated, what are they called?

Answer 14

chromosomes.

Question 15

what is the m phase ?

Answer 15

mitotic phase, mitosis and cytokinesis

Question 16

what occurs during mitosis (m phase)

Answer 16

chromosomes copies are separated from each other and move towards opposite ends of cell

Question 17

in what interphase phase (G1, S, and G2) are chromosomes duplicated in?

Answer 17

S phase

Question 18

what occurs in G1 phase?

Answer 18

metabolic activity and growth

Question 19

what occurs during s phase?

Answer 19

metabolic activity, growth, and DNA synthesis

Question 20

what occurs during G2 phase?

Answer 20

metabolic activity, growth, and preparation for cell division.

Question 21

where is all of the DNA in a cell?

Answer 21

in a genome

Question 22

what is a genome in pro and eukaryotic cells?

Answer 22

can consist of a single DNA molecule (prokaryotic)

number of DNA molecules (eukaryotic)

Question 23

dna molecules in a cell are packaged into ___?

Answer 23

chromosomes.

Question 24

what is a chromatin?

Answer 24

complex of DNA and protein that condenses during cell division

Question 25

what are somatic cells?

Answer 25

nonreproductive cells that have two sets of chromosomes

Question 26

what are gametes?

Answer 26

reproductive cells that have half as many chromosomes as somatic cells

Question 27

what happens in preparation for cell division?

Answer 27

DNA is replicated and chromosomes condense.

Question 28

what is cytokinesis?

Answer 28

the division of the cytoplasm

Question 29

what is the mitotic spindle?

Answer 29

a structure made of mictotubules that controls chromosome movement during mitosis

Question 30

where does the assembly of spindle microtubules occur in animal cells?

Answer 30

in the centrosome

Question 31

what is a centrosome?

Answer 31

type of microtubule-organizing center

Question 32

during what mitosis phase does the centrosome replicate?

Answer 32

interphase

Question 33

what does the mitotic spindle include?

Answer 33

centrosomes, spindle, microtubules, and asters.

Question 34

what is an aster?

Answer 34

a radial array of short microtubules.

Question 35

what happens in prometaphase?

Answer 35

1. nuclear membrane breaks down (NOT NUCEOLOUS) 2. spindle fibers of microtubules attach to centromere of sister chromatids

Question 36

what is a kinetochore?

Answer 36

a protein associated with centrosomes

Question 37

what is the metaphase plate?

Answer 37

an imaginary plane midway between the spindles two poles.

Question 38

what occurs during metaphase?

Answer 38

sister chromatids line up in the middle sister fibers pull apart.

Question 39

what occurs during prophase?

Answer 39

1. chromatin condenses to form chromosomes 2. nucleolus disappears. 3. MTOCS start and move to poles and make microtubules.

Question 40

what occurs during anaphase?

Answer 40

sister chromatics are going to pull apart to become daughter chromosome and move to opposite poles.

Question 41

what happens to cohesions in anaphase?

Answer 41

they are cleaved by an enzyme called separase.

Question 42

what occurs during telophase?

Answer 42

1. chromosomes are going back to condense chromatin 2. nucleolus reappears 3. nuclear membrane reappears

Question 43

what two proteins are involved in the cell cycle control system?

Answer 43

cyclins and cyclin dependent kinases (cdk)

Question 44

what are the checkpoints in the cell cycle control system do?

Answer 44

they signal where the cycle stops until go-ahead signal is received.

Question 45

what is mpf?

Answer 45

a cdk complex that triggers cell passage past G2 checkpoint into M phase.

Question 46

where are the 3 important checkpoints?

Answer 46

in G1,G2, and M

Question 47

where does the cell USUALLY receive the go-ahead signal?

Answer 47

G1 checkpoint

Question 48

what happens if cell doesn't get go-ahead signal?

Answer 48

will exit cell cycle (G0 phase)

Question 49

what are growth factors?

Answer 49

released by certain cells and stimulate other cells to divide.

Question 50

what is required for division of fibroblasts?

Answer 50

platelets.

Question 51

what is density-dependent inhibition?

Answer 51

where crowded cells will stop dividing.

Question 52

what do animal cells exhibit during density-dependent inhibition?

Answer 52

anchorage dependence

Question 53

what is the difference between cancer v normal cells?

Answer 53

cancer cells don't follow normal signs that regulate cell cycle.

Question 54

what are the 3 things that distinguish cancer cells?

Answer 54

1. they make their own growth factors 2. may convey growth factor signal without presence of growth factor 3. may have abnormal cell cycle control system

Question 55

what is the lump in cancer cells called?

Answer 55

bengin tumor