Cell Cycle & Cell Death

Question 1

where is DNA sequestered?

Answer 1

Nucleus

Question 2

what is the largest organelle in the cell?

Answer 2

nucleus

Question 3

how many subunits make up the nuclear pore complex?

Answer 3

8 large subunits

Question 4

what are the 4 zones of the nucleolus? What do each do?

Answer 4

fibrillar center - contain rRNA genes - 13,14,15,21,22
fine fibrillar / nuclear organizer center - transcription of rRNA genes
granular region / pars granulosa - initial ribosome assembly
chromatin assocated with nucleolus - looks like heterochromatin

Question 5

what makes up a nucleosome?

Answer 5

DNA + histone

Question 6

what is euchromatin (appearance + activity)?

Answer 6

less condensed

more transcriptionally active

Question 7

what is heterochromatin (appearance and activity)?

Answer 7

more condensed

less transcriptionally active

Question 8

what are the specialized sequences that make up a chromosome?

Answer 8

centromere
telomere
replication origin

Question 9

what is a centromere?

Answer 9

o centric heterochromatin, persistence throughout interphase, hold sister chromatids together, site of kinetochore formation

Question 10

what is a telomere?

Answer 10

at the end of the chromosome

allows chromosome to be replicated

Question 11

what is found in interphase?

Answer 11

G1, S, G2

Question 12

what is found in mitosis?

Answer 12

karyokinesis

cytokinesis

Question 13

what is the longest, most variable phase in the cell cycle?

Answer 13

G1/Gap 1

Question 14

what are the 2 checkpoints in the G1 phase? what do they use?

Answer 14

G1 DNA damage checkpoint - p53 Check

G1 restriction checkpoint (look at size, environment)- retinoblastoma protein (Rb)

Question 15

what happens during the S phase? What does S phase mean?

Answer 15

new sister chromatids are formed

DNA synthesis/replication

Question 16

what is the checkpoint in S phase?

Answer 16

S DNA damage checkpoint

Question 17

what happens in the G2 phase?

Answer 17

cell prepares for division

Question 18

what are the checkpoints in the G2 phase?

Answer 18

unreplicated DNA checkpoint

G2 DNA damage checkpoint

Question 19

what are the two checkpoints in the M phase?

Answer 19

spindle assembly checkpoint

chromosome segregation checkpoint

Question 20

what does the spindle assembly checkpoint do?

Answer 20

prevents premature entry into anaphase

Question 21

what does the chromosome segregation checkpoint do?

Answer 21

prevents cytoinesis until separation of chromosomes

Question 22

what are the stages of karyokinesis?

Answer 22

prophase
prometaphase
metaphase
anaphase
telophase

Question 23

what is mitosis?

Answer 23

asexual reproduction = division- produces 2 genetically identical daughter cells

Question 24

where is the nucleation site for growth of microtubules?

Answer 24

tubulin rings

Question 25

what does the microtubule organizing center contain?

Answer 25

1 pair of centrioles | many tubulin rings

Question 26

where is the kinetichore formed?

Answer 26

centromere?

Question 27

what is the function of the kinetichore?

Answer 27

attach chromosome to mitotic spindle

Question 28

what forms the mitotic spindle?

Answer 28

2 centrosomes microtubules motor proteins

Question 29

what happens during S phase?

Answer 29

replication of DNA | replication of centrosome

Question 30

what happens during the G2 to M transition?

Answer 30

centrioles of the duplicated centrosomes are moving to opposite poles their orientation determines the cells plane of division!

Question 31

what happens during prometaphase?

Answer 31

breakdown of nuclear envelope

Question 32

what happens during prophase?

Answer 32

nucleolus disassembles

Question 33

what happens during telophase?

Answer 33

sister chromatids are at opposite ends of poles nuclear envelope reassembles assembly of contractile ring

Question 34

what does cytokinesis result in?

Answer 34

creation of 2 daughter cells = diploid 2n

Question 35

what regulates G1?

Answer 35

cyclin D retinoblastoma (Rb) p53

Question 36

what regulates S phase?

Answer 36

cyclin E and A

Question 37

what regulates G2

Answer 37

cyclin A

Question 38

what regulates M

Answer 38

cyclin B | APC

Question 39

in the G1 phase, what do retinoblastoma do in resting cells?

Answer 39

inhibit progression to S phase because it holds onto E2F | tumor suppressor

Question 40

in the G1 phase, what do retinoblastoma do in active cells?

Answer 40

E2F dissociates and you have progression to S phase

Question 41

how is the APC activates?

Answer 41

separation of sister chromatids | degrading cyclin B

Question 42

when DNA damage is found, what happens in G1, S, G2 DNA Damage checkpoints?

Answer 42

activates tumor suppressors ATM and ATR

Question 43

what does the unreplicated DNA checkpoint do at G2?

Answer 43

prevents progression until DNA replication is complete | inactivates cyclin B

Question 44

what is the major thing that happens in M phase spindle assembly checkpoint

Answer 44

inhibition of APC - prevents premature anaphase

Question 45

what happens in the M phase chromosome segregation checkpoint?

Answer 45

prevents cytokinesis | makes sure that the chromosomes have been correctly separated first!

Question 46

what is unique about anaphase I?

Answer 46

random assortment - increases genetic diversity

Question 47

what does meiosis II produce?

Answer 47

genetically unique haploid gametes

Question 48

what is it called when the daughter cell only recieves one chromosome?

Answer 48

monosomy

Question 49

what is aneuploid? what are they commonly associated with?

Answer 49

an abnormal number of chromosomes, and is a type of chromosome abnormality cancer/tumor cells

Question 50

what are 5 stages of necrosis?

Answer 50

``` nuclear shrinkage (pyknosis) nuclear fragmentation (karyorrhexis) nuclear fading (karyolysis) nuclear dissolution anuclear necrotic cell ```

Question 51

what is released from the mitochondria during apoptosis?

Answer 51

cytochrome C

Question 52

why is there no inflammation in apoptosis?

Answer 52

macrophages release cytokines IL-10 and TGF -beta to inhibit inflammation!

Question 53

what is normal in embryological development, and in normal/abnormal tissue homeostasis?

Answer 53

apoptosis

Question 54

what is carcinoma?

Answer 54

malignant tumor growing from epithelial tissue

Question 55

what is sarcoma?

Answer 55

malignant tumor growing from connective tissue

Question 56

what makes up 90% of human cancers?

Answer 56

carcinoma