Lecture 2: Cell cycle

Question 1

G1 phase (3)

Answer 1

• normal cellular activities
• cell growth and duplication of organelles
• protein synthesis

Question 2

S phase (1)

Answer 2

• DNA replication ; very vulnerable

Question 3

G2 phase

Answer 3

• synthesis of protein and microtubules

Question 4

interphase (3)

Answer 4

• non-dividing stage = DNA replication and growth
• vulnerable to DNA damage during S phase
• rapidly dividing cells especially vulnerable (skin, GI, bone marrow)

Question 5

prophase (3)

Answer 5

• nuclear membrane disappears
• chromosomes condense
• centrioles migrate to opposite poles of the cell = mitotic spindle begins to form

Question 6

metaphase

Answer 6

paired chromosomes line up along the equator of the cell

Question 7

anaphase

Answer 7

• chromosomes separate and migrate to opposite poles

Question 8

telophase (2)

Answer 8

• nucleus divides into 2 identical cells with the same DNA composition
• cytokinesis occurs

Question 9

mitosis (3)

Answer 9

• occurs in most cells of the body
• results in 2 daughter cells containing DNA identical to parent cell
• each has 23 pairs of chromosomes = 46 total

Question 10

meiosis (2)

Answer 10

• occurs in sex cells located in the gonads

- results in 4 daughter cells with 1/2 the DNA content of the parent cell = 23 chromosomes

Question 11

specialized cells (4)

Answer 11

• lose the ability to divide
• red blood cells
• neurons
• muscle cells

Question 12

cells that can divide by stimulus (2)

Answer 12

• liver cells

- lymphocytes

Question 13

cells that continuously undergo cell division (4)

Answer 13

• high amount of S2 activity
• skin cells
• cells of intestinal lining
• bone marrow cells

Question 14

chromosome (2)

Answer 14

• single strand of DNA and protein containing genetic info

- held together by centromere

Question 15

chromatid

Answer 15

duplicated chromosome

Question 16

gene

Answer 16

unit of DNA at a specific locus that provides instructions for specific protein production

Question 17

centriole (3)

Answer 17

• organizing center for mitotic spindle composed of microtubules
• 2 per centrisome
• provide structural configuration and ability to separate genetic material

Question 18

karyotype (2)

Answer 18

• # of chromosomes an individual has

- humans have 23 diploid pairs = 46 total [22 pairs autosomes, 1 sex chromosome]

Question 19

hypertrophy

Answer 19

increase in size of cells

Question 20

atrophy

Answer 20

decrease in size of cells [ex. paralysis]

Question 21

hyperplasia

Answer 21

increased mitotic activity and # of cells

Question 22

metaplasia

Answer 22

changes in cell response to disease or chronic irritation = transformation of cell into a different cell type [ex. cancer metastasis]

Question 23

neoplasm

Answer 23

new cell mass/ rapid multiplication