9.8 DNA mutations

Question 1

UV radiation can cause chemical binding of adjacent _________. The most common mutant structure of DNA damage is the _________.

Answer 1

pyrimidines

thymine dimer

Question 2

chemical mutagens have a direct effect on the _________ of the base, changing it’s normal base pairing

Answer 2

chemical structure

Question 3

define conservative mis-sense mutation

Answer 3

a single amino acid change caused from a single base change, however, it changed to a similar amino acid

Question 4

mutation called when you have a single amino acid change caused from a single base change. The single base change in the coding region of a gene can alter the codon so it becomes a different amino acid. This can range in severity depending on where the change is.

Answer 4

mis-sense mutation

Question 5

for inversion mutations? what could happen if the break occurs in the middle of a gene? what if it encompasses the entire gene?

Answer 5

if in the middle, could be disastrous

if entire gene, could still function normally

Question 6

in the disease __________ ___________, there are defects in the DNA repair mechanism for thymine dimers from UV damage.

Answer 6

Xeroderma pigmentosum

Question 7

what is the mutation called when you put in new termination codon (NO amino acids beyond this point). Protein synthesis will stop at the new termination codon, truncated polypeptide. Generate premature stop codons.

Answer 7

nonsense mutations

Question 8

addition or deletion of a single base, alter the reading frame

Answer 8

frame shift mutation

Question 9

mutations that generate pre-mature stop codons:

Answer 9

nonsense mutations

NO more protein

Question 10

transposons and retroviruses are an example of _______.

Answer 10

insertions

they spontaneously insert themselves into DNA

Question 11

define non-conservative mis-sense mutation

Answer 11

a single amino acid change caused from a single base change, however, it changed to a completely characteristic of amino acid.

Question 12

what form of large-scale mutations genes occur when there was a break in the DNA - and it got flipped when repair mechanisms came in. Inverted. Scrambled gene

Answer 12

inversions

Question 13

chemical mutagens alter _____ _______

Answer 13

base pairing

Question 14

point mutations contrast from large-scale mutations. what are 3 types of point mutations?

Answer 14

mis-sense, nonsense, frameshift

Question 15

what can cause deletions in DNA?

Answer 15

ionizing radiation, X-rays, anything that physically breaks DNA

Question 16

In Xeroderma pigmentosum, there is a defect in _________ for dimers, leading to a high rate of:

Answer 16

DNA repair

skin cell death, high rate of skin cancers

Question 17

what main form of large-scale mutations occurs when after a break, something gets added.

Answer 17

insertions

Question 18

Burkitt’s lymphoma is caused by _________ of a proto-oncogene next to a _____________, which is very active

Answer 18

translocation

Ig heavy chain gene

Question 19

in insertions, what happens if something is inserted into a coding region or regulatory region?

Answer 19

may completely destroy gene function

Question 20

due to UV damage, once ________ are linked, they are no longer able to __________ correctly

Answer 20

thymines

base pair

Question 21

what are common sources of radiation exposure?

Answer 21

CT (even higher than spending an hour on a power plant)

X-ray is really small

Question 22

________________ is a cancer of lymphocytes, Occurs because during translocation, the c-myc proto-oncogene is ___________ next to Ig heavy chain region. Since the Ig is really active, it activates the myc gene.

Answer 22

Burkitt’s

translocated

Question 23

what main form of large-scale mutations occurs when DNA is physically broken and then rejoins?

Answer 23

deletions

tens to millions of base pairs can be removed

Question 24

main type of large-scale mutation where a whole piece of the chromosome is added or swapped with a whole piece of another chromosome?

Answer 24

translocations.