THE CELL CYCLE

Question 1

The human body must…

Answer 1

Precisely regulate the mitotic division of its adult stem cells to function as a coherent biological system

Question 2

Defective mitotic cell division can result in…

Answer 2

Abnormal cell growth and metastatic cancer

Question 3

What is the eukaryotic cell cycle?

Answer 3

The sequence of events the cell experiences from the time it is produced by the mitotic division of its parent cell until the time it divide to produce two daughter cells

Question 4

Divides

Answer 4

Reproduces

Question 5

Cell cycle duration for human adult stem cells and mature liver cells?

Answer 5

-24 hours for human adult stem cells
-1 year for mature liver cells (what allows the liver to regenerate)

Question 6

Interphase is comprised of

Answer 6

-G1: first gap
-S: synthesis
-G2: second gap

Question 7

What is the purpose of interphase?

Answer 7

It prepares the cell to reproduce by mitotic cell division

Question 8

G1 duration

Answer 8

~10 hours

Question 9

G1

Answer 9

-Commit to reproduce
-Begin organelle duplication
-Build more ribosomes to increase protein synthesis capacity
-Begin protein duplication
-Begin doubling cell size
-Synthesize deoxyribonucleotides and histones to support DNA synthesis during the next phase

Question 10

When does the G0 phase occur?

Answer 10

When the cell exits the cell cycle and is not preparing to reproduce

Question 11

When do adult stem cells in the G0 phase re-enter the cell cycle at the G1 phase?

Answer 11

When the body needs a new supply of cells

Question 12

Cells in G0 phase…

Answer 12

Perform their bodily functions

Question 13

Before S phase

Answer 13

The nucleus has 46 DNA molecules

Question 14

After S phase

Answer 14

The nucleus has 92 DNA molecules to ensure that each daughter cell inherits 46 DNA molecules

Question 15

Each chromosome and sister chromatid contains a

Answer 15

DNA molecule

Question 16

When does DNA replication occur?

Answer 16

During S phase

Question 17

DNA replication during S phase

Answer 17

-DNAP replicates (synthesizes) all 46 DNA molecules in the nucleus to ensure that each daughter cell inherits 46 DNA molecules
-The DNAP enzyme complex uses the rules of complementary base pairing to copy each strand of the DNA double helix

Question 18

G2

Answer 18

-All the remaining preparations required to reproduce are completed
-Ensures DNA synthesis was completed accurately
-All organelles and biological molecules are duplicated
-Cell size doubles
-Defective organelles and biological molecules are repaired
-Spindle formation begins

Question 19

How is the spindle formed?

Answer 19

Tubulin proteins are synthesized

Question 20

The spindle moves the ________ during what phase?

Answer 20

Chromosomes; M phase

Question 21

The G2 phase ended, the adult stem cell is

Answer 21

Prepared to reproduce and will enter the mitotic phase and reproduce by mitotic cell division

Question 22

What does mitotic cell division consist of?

Answer 22

Mitosis and cytokinesis

Question 23

After mitosis…

Answer 23

The cell has two nuclei and each nucleus has 46 DNA molecules

Question 24

During cytokinesis…

Answer 24

The cell separates to form two daughter cells