Chapter 12: The Cell Cycle

Question 1

What are the three main phases in the cell cycle?

Answer 1

Interphase
Mitosis/M Phase
Cytokinesis

Question 2

What are the phases entailed in interphase?

Answer 2

G1
S
G2

Question 3

What are the phases entailed in the Mitosis/M Phase?

Answer 3

Prophase
Metaphase
Anaphase
Telophase

Question 4

Describe interphase.

Answer 4

• majority of the cell’s life

- daily living of the cell (cell goes about regular functions and prepares for cell division)

Question 5

Describe the G1 Phase.

Answer 5

• cell grows in preparation for DNA replication
• centrosomes undergo replication (now two centrosomes)
• longer than S and G2 Phases

Question 6

Describe the S Phase.

Answer 6

• DNA is replicated
• occuring between G1 Phase and G2
• S stands for synthesis

Question 7

Describe the G2 Phase.

Answer 7

• organelles multiply until there are enough for two cells
• with all this activity, the cell often grows substantially during G2
• majority of cell growth occurs in G2

Question 8

Describe Mitosis.

Answer 8

Process where a single cell divides into two identical daughter cells; the two cells are identical; process of how we grow old and how old cells are replaced

Question 9

Why do people grow larger as they age?

Answer 9

Because they gain more cells, not because their cells grow larger

Question 10

How long do white blood cells live?

Answer 10

13 days

Question 11

How long do red blood cells live?

Answer 11

120 days

Question 12

Describe prophase.

Answer 12

• chromosomes condense
• centrosomes move to opposite sides of the cell/nucleus, initiating formation of the kinetochore microtubules
• nuclear envelope and nucleolus break down
• kinetochore microtubules (spindle fibers) expand and connect to kinetochores on the chromosomes

Question 13

Describe metaphase.

Answer 13

-chromosomes align themselves in the middle of the cell with the tugging of the kinetochore microtubules/spindle fibers

Question 14

Describe anaphase.

Answer 14

Sister chromatids break away from one another (at the centromeres) to the opposite poles of the spindle
For better separation, spindle fibers attached to other spindle fibers grow longer while those attached to kinetochores grow shorter; this process stretches the cell

Question 15

Describe telophase.

Answer 15

Two nuclear envelopes reform around each set of chromosomes
Chromosomes start to unwind
Two nucleoli form
Spindle fibers/kinetochore microtubules break down
Cleavage furrow forms
Mitosis is complete

Question 16

What is cytokinesis?

Answer 16

Cleavage furrow forms, which pinched the cell into two separate daughter cells; in a plant cell, a cell wall and membrane are created to cut off cell A and cell B