Chapter 12: The Cell Cycle

Question 1

Cell Division

Answer 1

reproduction of cells, enables one prokaryote to divide into 2, enables eukaryotes to develop and evolve

Question 2

Asexual Reproduction

Answer 2

a single celled eukaryotes dividing within itself

Question 3

Chromosome

Answer 3

tightly packed structures of DNA, each one consists of a single very long linear DNA molecule that carries 100-1000+ genes

Question 4

Genome

Answer 4

a cells DNA and genetic information

Question 5

Chromatin

Answer 5

the entire complex of DNA and proteins that build up chromosomes

Question 6

Somatic Cells

Answer 6

all body cells except reproductive cells

Question 7

Gametes

Answer 7

sperm and egg, have half as many chromosomes as somatic cells

Question 8

Sister Chromatids

Answer 8

joined copies of the original chromosome, two chromatids each containing an identical DNA molecule, are often attached along their lengths by protein complexes called cohesions in an attachment called sister chromatid cohesion

Question 9

Centromere

Answer 9

region in the chromatod made up of repetitive sequences in the chromosomal DNA where the chromatid is most closely to its sister chromatid

Question 10

Arm of Chromatid

Answer 10

portion of chromatid attached to each side of the centromere

Question 11

Mitosis

Answer 11

the division of genetic material in the nucleus

Question 12

Cytokinesis

Answer 12

usually immediately follows mitosis, division of the cytoplasm

Question 13

Meiosis

Answer 13

cell division in gametes that only produces daughter cells with one set of 23 chromosomes

Question 14

Cell Cycle

Answer 14

life of a cell from the time it is first formed during division of a parent cell until its own division into 2 daughter cells

Question 15

Mitotic (M) Phase

Answer 15

includes both mitosis and cytokinesis, shortest part of the cell cycle

Question 16

Interphase

Answer 16

much longer mitotic phase, often accounts for about 90% of the cell cycle, can be divided into 3 phases

Question 16

3 Phases of Interphase

Answer 16

G1, S, and G2
in all 3 phases, a cell grows by producing proteins and cytoplasmic organelles such as mitochondria and ER

Question 17

5 Stages of Mitosis

Answer 17

prophase, prometaphase, metaphase, anaphase, telophase

Question 17

Prophase

Answer 17

the chromatid becomes tightly compact and the nucleoli disappear, each duplicated chromosome appears as 2 identical sister chromatids and the mitotic spindle forms, the centrosomes move away from each other and are propelled partly by the lengthening of the microtubules between them

Question 18

Prometaphase

Answer 18

the microtubules from the centrosome invade the nuclear envelope and the centrosomes condense even more, the kinetochore forms at the centromere of each chromatid when the kinetochore microtubules form, the nonkinetochore microtubules interact with the opposite pole of the spindle to lengthen the cell

Question 19

Metaphase

Answer 19

the centrosomes are at opposite poles of the cell and the chromosomes are lining up at the metaphase plate across the center of the cell, the kinetochore of each chromosome of the sister chromatids are attached to kinetochore microtubules coming from opposite poles

Question 20

Anaphase

Answer 20

the homologous chromosomes are pulled to the centrosomes and go towards each separate pole

Question 21

Telophase and Cytokinesis

Answer 21

the chromosomes pull fully apart towards each entrosome, the cytoplasm begins forming a cleavage furrow that leads to it pinching off into 2 separate cells

Question 22

Cleavage Furrow

Answer 22

shallow groove in the surface of the cell near the metaphase plate, contractile ring of actin microfilaments associated with myosin molecules, actin and myosin interact and cause contraction

Question 22

Cell Plate

Answer 22

instead of animal cell cytokinesis, in telophase, golgi apparatuses move along the microtubules to the middle of the cell and coalesce, enlarges until its surrounding membrane fuses with the perimeter plasma membrane

Question 23

Binary Fission

Answer 23

asexual reproduction of single-celled eukaryotes, cell grows to about double its size and then divides to form two cells, involves mitosis in eukaryotes but no mitosis in prokaryotes

Question 24

Origin of Replication

Answer 24

place where cell division is initiated when the DNA of the bacterial chromosome begins to replicate, produces 2 origins

Question 25

Cell Cycle Control System

Answer 25

cyclically operating set of molecules that triggers and coordinates key events in the cell cycle

Question 26

Checkpoint

Answer 26

in the cell cycle, control point of cell regulation of the cycle, major ones are G1, G2, and M

Question 27

Cell Cycle Molecules

Answer 27

cyclin, cdk, mpf

Question 28

Cyclin

Answer 28

protein that attaches to a kinase, cyclically fluctuating function in the cell, activates kinases when attached

Question 29

CDK

Answer 29

cyclin dependent kinases, require cyclin to be activated, activity rises and falls with cyclin levels and concentration

Question 30

MPF

Answer 30

maturation promoting factor, cyclin-cdk complex, triggers cells passage from G2 to M

Question 30

G0 Phase

Answer 30

also called G not, nondividing state that a cell will go into if one of the phases detect a defect or division is not needed, most cells are in G0, cells can be brought in and out depending on if they are needed or not

Question 31

Growth Factor

Answer 31

protein released by certain cells to stimulate other cells to divide

Question 32

Density Dependent Inhibition

Answer 32

crowded cells stop dividing, physical factor for cell division and inhibition

Question 33

Anchorage Dependence

Answer 33

to divide, a cell must be attached to something like ECM or a culture flask, happens in most animal cells

Question 34

Transformation

Answer 34

indefinitely dividing cells, “immortal” divide even when the host is dead

Question 35

Benign Tumor

Answer 35

unable to replicate cancer cells in another place of the body, mass of abnormal cells in a place with normal tissue

Question 36

Malignant Tumor

Answer 36

cells whose genetic and cellular changes enable them to spread to new tissues and impair the functions of multiple organ systems

Question 37

Metastasis

Answer 37

cancer cells detaching from ECM or other anchors and spreading to other body tissues