Chapter 12: Cell Cycle

Question 1

Genome

Answer 1

A cell’s DNA

Question 2

Chromosomes

Answer 2

Structures containing DNA

Question 3

Chromatin

Answer 3

Entire complex of DNA and proteins that make up chromosomes

Question 4

Somatic cells

Answer 4

All the body cells except the reproductive cells. 2 sets of chromosomes, one from each parent

Question 5

Gametes

Answer 5

Reproductive cells. Half the chromosomes of body cells.

Question 6

Sister chromatids

Answer 6

Joined copies of original chromosome in a duplicated chromosome

Question 7

Cohesins

Answer 7

Attach sister chromatids along their lengths (sister chromatid cohesion)

Question 8

Centromere

Answer 8

Region of chromosome where chromatid most closely attached to sister chromatid

Question 9

Mitosis

Answer 9

Division of genetic material in nucleus

Question 10

Cytokinesis

Answer 10

Division of cytoplasm

Question 11

Mitotic (M) phase

Answer 11

Mitosis and cytokinesis part of the cell cycle (shortest part)

Question 12

Interphase

Answer 12

Longest part of cell cycle (90%). Cell grows and duplicates chromosomes. Divided into G1 phase, S phase, G2 phase

Question 13

S phase

Answer 13

DNA is replicated

Question 14

Mitotic spindle

Answer 14

Structure of microtubules, proteins, asters, centrosomes in cell division. Parts of cytoskeleton disassembles to form mitotic spindle

Question 15

Polymerize

Answer 15

Elongate (microtubules)

Question 16

Centrosome

Answer 16

Microtubule organizing center in the cell. Duplicates and then moves apart during cell division.

Question 17

Aster

Answer 17

Radial array of short microtubules extending from each centrosome

Question 18

Kinetochore

Answer 18

Structure of proteins on each sister chromatid centromere where spindle attaches. Each faces opposite directions. Depolymerizes spindle microtubules

Question 19

G2 of Interphase

Answer 19

• nuclear envelope
• 2+ nucleoli
• 2 centrosomes
• duplicated, not condensed chromosomes

Question 20

Prophase

Answer 20

• chromatin condenses
• no nucleoli
• chromosome appears as 2 sister chromatids joined together
• mitotic spindle begins to form (includes asters)
• centrosomes move away from each other (lengthening microtubules)

Question 21

Prometaphase

Answer 21

• nuclear envelope fragments (microtubules can enter nucleus)
• chromosomes condense more
• each sister chromatid has kinetochore where microtubules attach
• non kinetochore microtubules interact with those from opposite side

Question 22

Metaphase

Answer 22

• centrosomes at opposite poles
• chromosomes at metaphase plate
• kinetochores attached to kinetochore microtubules from opposite poles

Question 23

Anaphase

Answer 23

• shortest stage
• cohesins cleaved, sister chromatids detach
• daughter chromosomes move (centromere first)
• non kinetochore microtubules lengthen, kinetochore microtubules shorten

Question 24

Telophase

Answer 24

• 2 daughter nuclei, nuclear envelope reforms
• nucleoli reappear
• spindle goes away

Question 25

Metaphase plate

Answer 25

Imaginary plate in cell

Question 26

Cleavage

Answer 26

Process of cytokinesis

Question 27

Cleavage furrow

Answer 27

Shallow groove in cell surface by metaphase plate. Caused by contractile ring of actin microfilaments and myosin. Deepens until cell pinched in 2

Question 28

Cell plate

Answer 28

Coalescence of vesicles from Golgi apparatus in plant cytokinesis. Enlarges until it fuses with plasma membrane and forms 2 daughter cells

Question 29

Binary fission

Answer 29

Cell division in prokaryotes. Cell doubles in size and divides.

Question 30

Origin of replication

Answer 30

Spot where (circular) bacterial chromosome begins to replicate. Results in 2 origins. Each moves to opposite ends and continues to replicate.

Question 31

Dinoflagellate

Answer 31

Chromosome attaches to nuclear envelope (intact). Microtubules pass through nucleus inside cytoplasmic tunnels.

Question 32

Diatoms and yeast

Answer 32

Microtubules form within nucleus and separates chromosomes

Question 33

Cell cycle control system

Answer 33

Cyclic molecules triggering/coordinating events in cell cucle

Question 34

Checkpoint

Answer 34

Control point in cell cycle where signals can regulate cycle

Question 35

Cyclin

Answer 35

Protein that activates kinases which drive cell cycle. Accumulates through S and G2 phases. Degrades during G1.

Question 36

Cdk (cyclin dependent kinases)

Answer 36

Kinases that drive the cell cycle

Question 37

MPF

Answer 37

Cyclin Cdk complex. Promotes mitosis by phosphorylating various proteins. Peaks during metaphase, degraded during anaphase (Cyclin degrades)

Question 38

G0 phase

Answer 38

Nondividing phase (exit cell cycle). Most cells in humans in this phase.

Question 39

Growth factor

Answer 39

Protein that stimulates other cells to divide

Question 40

PDGF (platelet derived growth factor)

Answer 40

Made by platelets. Stimulate fibroblast division. Fibroblasts help heal wounds.

Question 41

Density dependent division

Answer 41

Crowded cells stop dividing.

Question 42

Anchorage dependence

Answer 42

Cell must be attached to substratum. Present in many animal cells.

Question 43

Transformation

Answer 43

Process where cell becomes able to divide indefinitely and behave like a cancer cell

Question 44

Benign tumor

Answer 44

Tumor that remains at one site

Question 45

Malignant tumor

Answer 45

Tumor that can spread to new locations

Question 46

Metastasis

Answer 46

Spread of cancer cells to new locations