Cell Cycle

Question 1

what two states do cells in the body alternate between

Answer 1

division & non-division

Question 2

what is a cell cycle

Answer 2

sequence of events from one division to another

Question 3

what are the 3 phases of somatic cells cell cycle

Answer 3

interphase, mitosis, cytokinesis

Question 4

longest phase; period of non-division

Answer 4

interphase

Question 5

division of the nucleus

Answer 5

mitosis

Question 6

division of the cytoplasm

Answer 6

cytokinesis

Question 7

Describe cell cycle variations

Answer 7

Some cells like bone marrow cells, pass through the cell cycle continually to form red blood cells (RBCs)

Some cells enter a “resting” or G0 phase
This state can be temporary and most cells in Go can reenter the cell cycle if conditions change
Other cells, like cochlear hair cells and neurons, that have reached an end stage of development will stay permanently in Go and will no longer divide

Question 8

when do cells become cancerous

Answer 8

when they escape from the control of the cell cycle

Question 9

where most cells spend their time

Answer 9

interphase

Question 10

period with active cell division

Answer 10

mitosis

Question 11

phase in interphase that most of the cell’s spend their lives and where extra organelles (ribosomes & proteins) are made

Answer 11

G1

Question 12

phase during interphase that DNA replicates (23 pairs to 46 pairs of chromosomes)

Answer 12

S phase (synthesis)

Question 13

what are the 3 phases of interphase

Answer 13

G1, S, G2

Question 14

preparing for mitosis (make microtubules) during this interphase

Answer 14

G2

Question 15

What do cells use the continuous supply of new cells for?

Answer 15

growth
development
repair

Question 16

phase with rapid growth and metabolic activity; centriole replication (8-10) hours

Answer 16

G1

Question 17

chromosome replication
DNA synthesis
6-8 hrs

Answer 17

S phase

Question 18

growth and final preparations for cell division
4-6 hrs

Answer 18

G2

Question 19

cell division

Answer 19

mitosis

Question 20

first phase of the cell cycle and is the longest part
time interval between cell divisions

Answer 20

interphase

Question 21

what occurs during the 3 phases of interphase

Answer 21

daughter cells that resulted from mitosis undergo a period of growth and synthesis

Question 22

immediately follows mitosis
cell doubles in size

Answer 22

G1

Question 23

what organelles are synthesized in G1

Answer 23

RNA, proteins, cell membranes, ribosomes, and other organelles in the cytoplasm

Question 24

describe what happens during G1 of interphase

Answer 24

cell doubles in size
directly after mitosis
organelles in cytoplasm synthesize
cell pieces lost in cell division get replaced
chromosomes are unduplicated (1 molecule of DNA)

Question 25

describe what happens during S phase

Answer 25

duplication of each chromosome occurs (two identical daughter DNA molecules) DNA is replicated and doubles chromosomes very long and spread throughout the nucleus

Question 26

what apoptosis

Answer 26

cell suicide happens when damage to a cell is too severe to repair itself

Question 27

causes damage to surrounding cells

Answer 27

necrosis

Question 28

doesn’t cause damage ot surrounding cells

Answer 28

apoptosis

Question 29

describe G2 phase

Answer 29

interval following DNA replication and before mitosis 2nd period of cellular growth mitochondria divide spindle fiber precursosrs form

Question 30

when are the cells ready to divide

Answer 30

at the end of G2

Question 31

what are the checkpoints built into the cell to prevent defective cells from going through mitosis and dividing

Answer 31

G1 - ensure readines for DNA synthesis G2 - determines if cell is ready to enter mitosis and divide

Question 32

what is the second phase of the cell cycle

Answer 32

mitosis

Question 33

This type of cell division is essential to allow multicellular organisms to grow and repair damaged tissue

Answer 33

mitosis

Question 34

before mitosis do the chromosomes double in number?

Answer 34

yes, they go from 46 to 92

Question 35

how can we see genetic consequences?

Answer 35

errors in distrution of chromosomes to the two daughter cells

Question 36

at the end of mitosis, what do each daughter cell receive?

Answer 36

one half (diploid number) of the doubled chromosomes material that occurs prior to mitosis maintaining the same number of chromosomes as the mother cell

Question 37

how many phases does mitosis have

Answer 37

4 prophase metaphase anaphase telophase

Question 38

during the DNA replication (S) phase, chromosomes are

Answer 38

extremely long and diffusely spread through the nucleus

Question 39

when do chromosomes coil thicken and shorten to become the recognizable chromosome

Answer 39

prophase in mitosis

Question 40

which phase do each replicated chromosome comprise of two sister chromatids, with identical genetic info joined at the centromere

Answer 40

end of prophase in mitosis

Question 41

when do centrioles duplicate

Answer 41

at the start of mitosis

Question 42

what is an aster

Answer 42

Arrangement of microtubules, star like pattern, mechanically strengthens the spindle apparatus