Mutations and DNA replication/repair

Question 1

how does depurination happen

Answer 1

bone between base and deozyribose spontaneously hydrolyzes

Question 2

what is the most common deamination

Answer 2

spontaneous conversion of cytosine to uracil

Question 3

how do you get pyrimidine dimers

Answer 3

UV light dimnerizes adjacent thymine bases

Question 4

somatic muation

Answer 4

affects only the cell where the mutation happens

Question 5

what happens if you have somatic muation early in embryogenesis

Answer 5

mosaicism

Question 6

germline mutation

Answer 6

mutations gets passed to offspring

Question 7

gene mutation

Answer 7

variation in nucleotide seque3nces

Question 8

genomic mucations

Answer 8

surplus o rloss of chromosomes

Question 9

chromosomal mutaitons

Answer 9

rearrangements, deletions, or duplications o fchromosomal regions

Question 10

mutations involving chromatin

Answer 10

changes in methylation of DNA

Question 11

what is the most common type of mutaiton

Answer 11

gene mutation

Question 12

what are the 3 mechanisms that cause small insertions and deletions

Answer 12

incorrect recomination
strange slippage
intercalating agents

Question 13

what happens iwth incorrect recomination

Answer 13

unequal crossover

Question 14

where is incorrect recombination more likely to happen

Answer 14

loci that have repetitive DNA

Question 15

where is strand slippage during replication likely to happen

Answer 15

areas of repetitive sequence

Question 16

intercalating agents

Answer 16

chemical mutagens that fuck up DNA

Question 17

what is a source of chromosomal and genome mutation

Answer 17

meiosis

Question 18

prophase I

Answer 18

chromosomes condense and become visible

Question 19

synaptonemal complex

Answer 19

holds together homologous chromosomes

Question 20

chiasmata

Answer 20

sites of crossovers

Question 21

metaphase

Answer 21

chromsomes are positioned at the equator

Question 22

anaphase

Answer 22

chromsomes are serparted, pulled to opp. poles

Question 23

process of pulling the chromsomes apart and to opposite ends of the cell

Answer 23

disjunction

Question 24

nondisjunction

Answer 24

incomplete separation of chromosomes in anaphase

Question 25

the frequency of nondisjunction increases with waht

Answer 25

maternal age

Question 26

how does gene mapping work

Answer 26

use frequency of recombiantion between genes on teh same chromosome as an indicator of their proxiximity

Question 27

3' --> 5' exonuclease activity of DNA polymerase delta

Answer 27

responsible for bulk of DNA synthsis during replication process

Question 28

what happens if an incorrect nuclteotide is found by the exonuclase

Answer 28

it hydrolyzes the new phosphodiester bond adn the polyermase tries again for correct base pairing

Question 29

what is HNPCC caused by

Answer 29

defects in mismatch repair system

Question 30

DNA glycosylases

Answer 30

recognize specific types of altered base in DNA and catalyze their hydrolytic removal

Question 31

nucleotide excision repair

Answer 31

repairs damage caused by agents that result in large changes in structure of DNA

Question 32

waht casues xeroderma pigmentosum

Answer 32

mutation that abolism or impair function of nucletoide excision repair

Question 33

symptoms of xeroderma pigmentosum

Answer 33

extreme sensitivity of skin to sunlight

Question 34

nonhomoglous end joining

Answer 34

you just connect the breaks without adding back what was lost

Question 35

homologous end joinging

Answer 35

us the recombination processes to repair broken DNA, no loss of information

Question 36

how is cytarabine different from cytidine

Answer 36

contains arabinosine instead of ribose

Question 37

what do you treat with cytarabine

Answer 37

acute leukemias

Question 38

how does cytarbine work

Answer 38

turns into cytarabine triphosphate inside cells. competes with deoxyribonucleotides for binding to DNA polymerase, blocking DNA replication

Question 39

what do you treat with cyclophosphamide

Answer 39

hodgkin's lymphoma

Question 40

how does cyclophosphamide work

Answer 40

acts as alkylating agents, does damage to DNA

Question 41

what is doxorubicin

Answer 41

anthracycline antibotic

Question 42

how does doxorubicin work

Answer 42

forms complex with DNA and toposimoerase II

Question 43

how does toposiiomerase II work

Answer 43

passing 1 double stranged DNA seg throough a double stranged break in another double stranded DNA segment

Question 44

what happens after doxorubicins binds to toposiomerase II

Answer 44

double stranded breaks accumulate, lead to apoptosis