Cell Cycle

Question 1

Interphase

Answer 1

period between mitotic divisions

G1
S
G2

18-24 hours in lab cells

Question 2

Mitosis

Answer 2

cell division that produces 2 cells

usually less than 1 hour in lab cells

Prophase
Metaphase
Anaphase
Telophase

Question 3

Cytokinesis

Answer 3

cleavage furrow forms and deepens

cytoplasmic division

Question 4

Stages of cell cycle

Answer 4

interphase
mitosis
cytokinesis

Question 5

G0

Answer 5

inactive stage between cytokinesis and G1

white blood cells enter G0, later reenter G1, and divide

Question 6

G1

Answer 6

immediately after mitosis
cell growth BEFORE DNA replication
production of cytoplasmic components like organelles, ribosomes, membranes, RNA
cell size doubles

Question 7

S (synthesis)

Answer 7

DNA replication = chromosomes duplicated

sister chromatids form

Question 8

G2

Answer 8

cell becomes ready to divide
mitochondria divide
precursors of spindle fibers synthesized

Question 9

Prophase

Answer 9

PREPARE
chromosomes condense and become visible
nuclear envelope disappears
centrioles divide, migrate to opposite poles of cell
spindle fibers form and attach to chromosomes, stretch across the cell

Question 10

Metaphase

Answer 10

chromosomes line up on the MIDDLE of cell

46 centromeres, each attached to 2 sister chromatids

Question 11

Anaphase

Answer 11

APART
chromosomes begin to separate
each sister chromatid is converted into a chromosome
briefest stage, but ensures each cell receives an identical set of 46 chromosomes.

Question 12

Telophase

Answer 12

chromosomes reach opposite poles and decondense
spindle fibers break down
new nuclear envelope forms
mitosis is completed

Question 13

Meiosis

Answer 13

one cycle of chromosomal replication followed by 2 successive cell divisions = 4 haploid cells
homologous chromosomes

Question 14

Reduction division

Answer 14

chromosome number reduced to half (46 to 23, diploid to haploid)
meiosis I

Question 15

Prophase I of Meiosis

Answer 15

each chromosome pairs with its homologue
crossing over
spindle microtubules attach to each chromosome

Question 16

Metaphase I of Meiosis

Answer 16

chromosomes and spindle poles move apart, into position midway between poles

Question 17

Anaphase I of Meiosis

Answer 17

homologous partners move to opposite poles

Question 18

Telophase I of Meiosis

Answer 18

cytoplasmic divison to produce 2 haploid cells, with one of each chromosome type
chromosomes are still in the DUPLICATED state

Question 19

Prophase II of Meiosis

Answer 19

microtubules attach to the chromosomes

Question 20

Interkinesis (Meiosis)

Answer 20

no DNA replication between two nuclear divisions

Question 21

Metaphase II of Meiosis

Answer 21

duplicated chromosomes positioned midway between the two poles

Question 22

Anaphase II of Meiosis

Answer 22

sister chromatids of each chromosome move to opposite spindle poles
each ‘sister’ chromatid is now a chromosome

Question 23

Telophase II of Meiosis

Answer 23

4 haploid daughter nuclei produced

all chromosomes are now in the unduplicated state.

Question 24

Spermatogenesis

Answer 24

primary spermatocytes enter meiosis
after meiosis i = secondary spermatocytes
after meiosis ii = haploid spermatids, undergo changes and become mature sperm

Question 25

Oogenesis

Answer 25

primary oocytes enter meiosis during embryonic development, arrest in meiosis i
one oocyte per menstrual cycle completes meiosis i just before ovulation
haploid secondary oocyte is formed, along with a polar body (nonfunctional)
if secondary oocyte is fertilized, meiosis is completed (sperm stimulates meiosis ii)