Chapter 1 (nucleic acid structure)

Question 1

Chemotherapeutics that target S phase

Answer 1

Methotrexate , 5-fluorouracil and hydroxyurea

Question 2

On what phase does Bleomycin target ?

Answer 2

G2 phase

Question 3

Chemotherapeutics that target M phase

Answer 3

Vincristine , vinblastine and paclitaxel

Question 4

Non-cell cycle specific chemotherapeutics ?

Answer 4

Cyclophosphamide and Cisplatin

Question 5

Reversed transcription is commonly associated with ?

Answer 5

Retroviruses

Question 6

Base only present in DNA

Answer 6

Thymine

Question 7

Base only present in RNA

Answer 7

Uracil

Question 8

Which base is almost always attached to deoxyribose ?

Answer 8

Thymine

Question 9

Chargaff’e rules

Answer 9

In dsDNA : the amont of A equals that of T and amount of G equals that of C thus total purines equals total pyrimidines

Question 10

Histones are rich in which proteins ?

Answer 10

Lysine and arganine

Question 11

Can induce negative supercoiling in E coli DNA ?

Answer 11

DNA gyrase ( DNA topoisomerase ll )

Question 12

Chromosome abnormalities can be assessed by ?

Answer 12

Karyotype analysis of metaphase chromosomes or Banding techniques of prophase and prometaphase chromosomes

Question 13

Where and when does transcription occur ?

Answer 13

In the nucleus throughout the interphase ( G1-S-G2 )

Question 14

Where and when does translation occur ?

Answer 14

In the cytoplasm throughout the cell cycle (G1-S-G2-M)

Question 15

Where and when does replication occur ?

Answer 15

In the nucleus during S-phase

Question 16

How the cell cycle is being controlled ?

Answer 16

By Cyclins and Cyclin- dependent kinases

Question 17

Adenosine deaminase deficiency ?

Answer 17

SCIDS

Question 18

Purines other than adenine and guanine ?

Answer 18

Xanthine , hypoxanthine and uric acid

Question 19

Why does nucleoside di and tri phosphate are high energy compounds ?

Answer 19

Because of the hydrolytic energy associated with the acid anhydride bonds

Question 20

Watson-Crick DNA ?

Answer 20

Right handed double helical molecule with about 10 base pairs per complete turn of the helix

Question 21

Z-DNA ?

Answer 21

Rare left handed double helical form of DNA that occurs in C-G rich sequences

Question 22

Daunorubicin and Doxorubicin mechanism ?

Answer 22

Intercalating between the bases of DNA interfering with the activity of Topoisomerase ll and preventing proper replication ( used in ttt of leukemias )

Question 23

Cisplatin mechanism ?

Answer 23

Bind tightly to the DNA causing structural distortion and malfunction

Question 24

Methods for double helical DNA denaturation ?

Answer 24

Heat
Alkaline ph
Chemicals : formamide and urea

Question 25

Where does ribosomal assembly occur ?

Answer 25

In the nucleolus