Cytology 2

Question 1

Mitosis

Answer 1

Cell division; a parent cell gives rise to identical daughter cells

Question 2

Why do cells divide?

Answer 2

1. Growth
2. Repair
3. Replacement

Question 3

Cell Cycle

Answer 3

All cellular activities from formation to death/division

Question 4

Phases of a cell cycle

Answer 4

1. Interphase

2. Cell Division

Question 5

2 Types of Nuclear Division

Answer 5

1. Mitosis (somatic cell division)

2. Meiosis (reproductive cell division)

Question 6

Cytokinesis

Answer 6

Division of the cytoplasm; occurs in mitosis and meiosis

Question 7

Interphase - G1 Phase

Answer 7

“Growth”

- organelle production
- metabolism
- protein synthesis
- centriole replication begins (if mitotically capable)

Question 8

Interphase - S Phase

Answer 8

“Synthesis”

- preparation for division
- Nuclear DNA replication
- short duration

Question 9

Interphase - G2 Phase

Answer 9

• brief
• synthesis of enzymes for division
• organelle production
• centriole replication completes

Question 10

Two functions of DNA double helix

Answer 10

1. Replication
2. Protein synthesis
   a. DNA –> mRNA –> protein
   b. copies

Question 11

Mitosis

Answer 11

• Growth & repair of somatic cells
• “M” Phase; Nuclear Division
• distributes 2 sets of chromosomes into 2 identical daughter cells
• does not occur in most mature cells of nervous tissue, skeletal muscle, and cardiac muscle

Question 12

Phases of Mitosis

Answer 12

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

Question 13

Karyotyping

Question 14

Mitosis: Prophase

Answer 14

• Chromatin –> Chromosomes
• nuclear membrane and nucleoli break up
• spindle formation begins
• spindle microtubules attach to centromeres

Question 15

Mitosis: Metaphase

Answer 15

• chromosomes align at equitorial plane

Question 16

Mitosis: Anaphase

Answer 16

• centromeres separate, separating sister chromatids into 2 chromosomes
• spindle fibers pull chromosomes to opposite poles
• cytokinesis starts

Question 17

Mitosis: Telophase

Answer 17

• chromosomes at opposite poles
• nuclear membrane reassembled
• spindle breaks up
• chromosomes –> chromatin
• nucleoli reassemble
• cytokinesis ends at end of phase

Question 18

Cell Division: Cytokinesis

Answer 18

• division of the cytoplasm and organelles
• begins during anaphase and completed by the end of telophase
• cleavage furrow divides cytoplasm
• results in 2 daughter cells

Question 19

Cell Death

Answer 19

1. Follows Interphase; may occur during division
2. Two mechanisms:
   
   • Necrosis (not healthy) - pathological cell death from tissue injury
   • Apoptosis (healthier) - cellular suicide
     
     • removes harmful cells (virus/DNA damage)
     • promotes normal development