Lec 2 The Life of A Cell

Question 1

What are the two stages of the Cell Cycle?

Answer 1

Interphase ("resting phase") 
Mitotic Phase (nuclear division)

Question 2

What are the 3 stages of Interphase?

Answer 2

G1 Phase, S Phase, G2 Phase

Question 3

What occurs during the G1 Phase?

Answer 3

Normal cellular activities
cell growth + duplication of organelles
protein synthesis

Question 4

What occurs during the S Phase?

Answer 4

DNA replication.

Cell is very vulnerable to events that can cause DNA damage

Question 5

What occurs during the G2 Phase?

Answer 5

synthesis of protein, microtubules, etc

Question 6

What are the possible fates of daughter cells?

Answer 6

• enter a new cycle immediately
• rest as an uncommitted cell
• differentiate -> age -> die

Question 7

what occurs during cytokinesis?

Answer 7

cytoplasmic division

Question 8

what are examples of cells that are extremely specialized and have lost their ability to divide?

Answer 8

red blood cells (mature) -> no nucleus
neuron (nerve cell)
muscle cell (increase in size, not number)

Question 9

what are examples of cells that normally do not divide, but can be induced to do so by an appropriate stimulus?

Answer 9

liver cells

lymphocytes [WBCs]

Question 10

which cells continuously undergo cell division?

Answer 10

skin cells
cells of the intestinal lining
bone marrow cells

*esp true for cells which are subject to frequent destruction.

Question 11

what is the chromatin?

Answer 11

dna and protein. tangled/nucleus at rest

Question 12

what is the chromatid?

Answer 12

duplicated chromosomes

Question 13

what is a karyotype?

Answer 13

of and types of chromosomes an individual has (46)

Question 14

Which cells are most vulnerable to damage during the S-Phase?

Answer 14

rapidly diving cells such as bone marrow, skin, and GI tract.

Question 15

what are the 4 stages of mitosis? name them in order.

Answer 15

prophase
metaphase
anaphase
telophase

Question 16

What occurs during prophase?

Answer 16

nuclear membrane disappears and chromosomes become condensed.

mitotic spindle forms

Question 17

what occurs during metaphase?

Answer 17

paired chromosomes line along the equator of the cell

Question 18

what occurs during anaphase?

Answer 18

chromosomes separate and migrate to opposite sides of the cell

Question 19

what occurs during telophase?

Answer 19

nucleus divides into 2 cells which have the same composition of DNA

cytokinesis occurs (splits into 2)

Question 20

What is the result of mitosis?

Answer 20

2 identical daughter cells are produced. these cells will enter the phases of the cell cycle and may either…

1. immediately divide again
2. rest
3. remain permanently in interphase

Question 21

difference between mitosis and meiosis?

Answer 21

mitosis involves cell division, occurs in most cells of the body, results in 2 daughter cells identical to the parent cell, and produces 23 pairs [46 chromosomes]

meiosis is cell division that occurs in the gonads or sperm. it results in 4 daughter cells which contain HALF the dna or chromosomes of the parent cell [23]

Question 22

which term means decrease in size of cells?

Answer 22

atrophy

Question 23

what is hyperplasia?

Answer 23

increase in mitotic activity

Question 24

what is metaplasia?

Answer 24

change in cell response to disease, which results in the transformation of the cell into a diff cell type.