Questions and answers for exam Preparation

MCQs

Total Questions : 72 | Page 3 of 8 pages

Question 21. Errors can be introduced because of many reasons such as polymerase error or because of heterogeneity. Which of the statement holds true?

The error caused because of polymerase is biased for the first position in the codon
The error caused because of polymerase is evenly distributed on all the positions in the codon
The error caused by sequence heterogeneity is mainly because of first position in the codon
The error caused by sequence heterogeneity is evenly distributed on all the codon positions

Discuss Question

Answer: Option B. -> The error caused because of polymerase is evenly distributed on all the positions in the codon
Answer: (b).The error caused because of polymerase is evenly distributed on all the positions in the codon

Question 22. Which of the statement is incorrect for jumping PCR?

It is used in the case when the DNA fragment is degraded
In this type of PCR, the molecules are not long enough to span between the two primer sites
At the end of first round of synthesis, the extension of the molecule from the primer site to the end of the fragmented molecule takes place
It doesn’t leads to the formation of chimeric product

Discuss Question

Answer: Option D. -> It doesn’t leads to the formation of chimeric product
Answer: (d).It doesn’t leads to the formation of chimeric product

Question 23. An alternative to adding polymerase at later stage is __________

Make the polymerase inactive by binding it to an antibody
Introduce the polymerase or Magnesium in clay beads
Make the polymerase inactive by attaching groups which cause stearic inhindrance
Introduction of polymerase or Magnesium in plastic wires

Discuss Question

Answer: Option A. -> Make the polymerase inactive by binding it to an antibody
Answer: (a).Make the polymerase inactive by binding it to an antibody

Question 24. What are the possibilities which can occur until the temperature has reached for primer annealing?

Extension doesn’t starts until the appropriate temperature is reached
Extension may start even when the temperature is low
At low temperature, there is specific annealing of primer taking place
There are more specific products which are generated

Discuss Question

Answer: Option B. -> Extension may start even when the temperature is low
Answer: (b).Extension may start even when the temperature is low

Question 25. Hot-start PCR is a modification of PCR. Which of the following is not corresponding to it?

The basis is that extension is not started until the first cycle reaches its maximum temperature
The polymerase is added after the first cycle has reached its maximum temperature or melting temperature
It is satisfactory for small number of samples
It leads to generation of non specific products

Discuss Question

Answer: Option D. -> It leads to generation of non specific products
Answer: (d).It leads to generation of non specific products

Question 26. The primer annealing temperature is often very low from the maximum temperature. This low temperature leads to some mismatches.

True
False
May be True or False
Can't say

Discuss Question

Answer: Option A. -> True
Answer: (a).True

Question 27. If two successive PCRs are carried out, in which PCR there are chances of having a non-specific product?

First PCR
Second PCR
Both the PCRs
It depends on the annealing temperature

Discuss Question

Answer: Option A. -> First PCR
Answer: (a).First PCR

Question 28. If two successive PCR are carried out, it is called as __________

Touch-down PCR
Hot-start PCR
Combined PCR
Nested PCR

Discuss Question

Answer: Option D. -> Nested PCR
Answer: (d).Nested PCR

Question 29. Touch-down PCR is another modification. Its characteristics include:

Lowering the temperature for primer annealing
Primer annealing is done at higher temperatures initially
The temperature is abruptly reduced in the second cycle
In earlier cycles less stringent conditions are there and in later cycles, more stringent conditions are there

Discuss Question

Answer: Option B. -> Primer annealing is done at higher temperatures initially
Answer: (b).Primer annealing is done at higher temperatures initially

Question 30. The process of inserting an amplified PCR product in a vector for cloning is known as __________