Cell Bio

Question 1

DNA polymerase __ makes daughter DNA strands;

DNA polymerase __ replaces RNA primers with DNA segments

Answer 1

III

I

Question 2

Unlike DNA polymerase III, DNA polymerase I has __ exonuclease activity that can remove RNA primers and damaged DNA segments.

Answer 2

5’→ 3’

Question 3

The __ exonuclease activity of DNA polymerase I and III provides a proofreading function that fixes mismatched nucleotides in the newly formed daughter strands.

Answer 3

3’→ 5’

Question 4

a DNA-dependent RNA polymerase that incorporates short RNA primers into replicating DNA.

Answer 4

Primase

Question 5

uses double-stranded DNA probes

Answer 5

Southwestern Blotting

DNA binding proteins

Question 6

Xeroderma pigmentosum is an autosomal recessive disorder characterized by defective nucleotide excision repair often caused by a deficiency in UV-specific ____.

Answer 6

endonuclease

Question 7

Prokaryotic topoisomerase __ (DNA gyrase) is inhibited by fluoroquinolone antibiotics, whereas eukaryotic topoisomerase _ is inhibited by the anticancer drug etoposide.

Answer 7

II

II

Question 8

Cytosine deamination fixed first via ____ → endonuclease → lyase → polymerase → ligase

Answer 8

Glycolyase

Question 9

an autosomal recessive condition caused by mutations in the genes responsible for the repair of interstrand DNA crosslinks. It is the most common inherited cause of aplastic anemia and presents with short stature, absent thumbs, and increased malignancy risk.

Answer 9

Fanconi anemia

Question 10

DNA synthesis can occur only in the ___ direction.

Answer 10

5’→3’

Question 11

Telomeres help maintain chromosomal integrity and are preserved in ___ cell lines (epithelial cells, lymphocytes, hematopoietic stem cells) by telomerase.

Answer 11

rapidly dividing

Question 12

DNA polymerase __ is unique as it is the only prokaryotic polymerase that also has 5’ to 3’ exonuclease activity. This activity functions to remove the RNA primer created by RNA primase and repair damaged DNA sequences.

Answer 12

I

Question 13

DNA polymerase I is unique as it is the only prokaryotic polymerase that also has __ exonuclease activity.

Answer 13

5’ to 3’

Question 14

Removal of Supercoils in prokaryotes

Answer 14

DNA Gyrase (Topoisomerase II)

Question 15

Exposure to ionizing radiation induces DNA ___ and the formation of oxygen free radicals.

Answer 15

double-strand fractures

Question 16

DNA ___ can be induced by numerous chemical and physical agents, notably alkylating agents used in cancer treatment.

Answer 16

cross-linking