Review 3

Question 1

Which statement best describes the ‘semi conservative replication’ of DNA?

Answer 1

In each replication cycle, one of the parental strands is conserved

Question 2

Which of the following enzymes is not involved in DNA replication?

Answer 2

Reverse transcriptase

Question 2

The template is read in replication in the-

Answer 2

3’-5’ direction

Question 3

The prokaryotic DNA chain elongation is carried out by

Answer 3

DNA polymerase III

Question 4

In a newly synthesized prokaryotic DNA strand, the primers are removed by-

Answer 4

DNA polymerase I

Question 5

In the genetic disease, Xeroderma pigmentosum, the cells fail to repair the damaged DNA, due to the defect in the-

Answer 5

Nucleotide excision repair

Question 6

In a segment of DNA exposed to chemicals Cytosine has been deaminated to Uracil, Which of the following mechanisms will remove Uracil and incorporate the
correct base?

Answer 6

Base excision repair

Question 7

Which of the followings does NOT need a primer in order to function?

Answer 7

RNA polymerase

Question 8

Which of the followings is required for end to end joining of DNA

Answer 8

DNA ligase

Question 9

Which of the following enzyme(s) can remove or insert supercoil twists into circular DNA?

Answer 9

Topoisomerases

Question 10

In which phase of the cell cycle does DNA replication occur?

Answer 10

S

Question 10

The enzyme responsible for initiating DNA replication in prokaryotes is:

Answer 10

Primase

Question 10

The enzyme responsible for continuing DNA replication in prokaryotes, once it is initiated is:

Answer 10

DNA polymerase III

Question 10

Antibiotics such as Ciprofloxacin and Flouroquinolines work by inhibiting a specific enzyme. This enzyme is normally necessary to relieve torsional strain that is caused by the unwinding of the helix. What is the name of this enzyme?

Answer 10

Topoisomerase (DNA Gyrase)

Question 10

The following are features of DNA replication EXCEPT:

Answer 10

unidirectional

Question 11

The promoter region in prokaryotic transcription is recognized by?

Answer 11

σ Factor of RNA polymerase

Question 12

17- Choose the incorrect statement about RNA polymerase?

Answer 12

Can not initiate chain synthesis

Question 13

The chemical structure of 5’ cap of eukaryotic m RNA cap is？

Answer 13

7- methyl guanosine triphosphate

Question 14

The prokaryotic RNA chain elongation is carried out by

Answer 14

Core enzyme

Question 15

Eukaryotic RNA polymerase I is specialized to transcribe which of the following?

Answer 15

Ribosomal RNA

Question 16

A promoter site on DNA ？

Answer 16

is present upstream to the start site
is present on the coding strand
Initiates transcription
Answer : All of the above

Question 16

What is added to the 3′-end of many eukaryotic mRNAs after transcription?

Answer 16

Poly A tail

Question 17

Which of the following does not have introns?

Answer 17

Processed mRNA

Question 18

Alternative splicing…

Answer 18

Creates different proteins from a single gene

Question 19

The Rho protein is involved in the _____ stage of transcription.

Answer 19

Termination

Question 20

The enzyme that accomplishes transcription is termed:

Answer 20

RNA polymerase.

Question 21

The complimentary messenger RNA strand that would be synthesized from the DNA base sequence of CTGAC would be…

Answer 21

GACUG.

Question 21

An endonuclease is an enzyme that hydrolyzes:

Answer 21

A phosphodiester bond located in the interior of a polynucleotide

Question 21

The anticodon region is an important structural component of-

Answer 21

t-RNA

Question 21

RNA splicing joins together:

Answer 21

two exons.

Question 22

In protein synthesis which out of the following is not a termination codon?

Answer 22

UUU

Question 23

A 20 year old man was diagnosed with abnormal form of β – globin (Hemoglobin Constant Spring) which is longer than the normal protein, which of the following point mutation is consistent with the abnormality?

Answer 23

UAA——->CAA

Question 24

Which one of the following molecules is not a component of the 30 S initiation complex?

Answer 24

ATP

Question 25

A student is trying to explain the process of protein synthesis. The most accurate summary of the steps would be

Answer 25

DNA makes RNA makes protein

Question 26

Stop codons

Answer 26

do not code for an amino acid