Genetic Engineering Practice Test 4

1. endA mutation is often induced in host molecules. Choose the correct statement.

It enhances the quality of plasmid DNA preparations only

It activates the gene for DNA-specific endonuclease

It enhances the yield of plasmid DNA preparations only

It enhances both the quality and yield of plasmid DNA preparations

2. At times it is observed that non-recombinant plasmids are more than that of recombinant plasmids. Choose the correct statement in regard to it.

It makes easier to get the recombinant plasmids from the mixture

Alkaline phosphatase method is less reliable in comparison to the ratio method

The ratio of insert DNA to vector DNA is reduced to get recombinant plasmids

Alkaline phosphatase is used to get recombinant plasmids

3. Physical separation is also used at times. Choose the correct statement with respect to this method.

Gel is more efficient than the sugar density gradient

The central portion is recovered from the gel or the gradient

Physical separation constitutes of gel electrophoresis and or by using centrifugation in sugar density gradient

In sugar density gradient, the molecules are separated on the basis of density

4. How many phases are there for replication of lambda DNA to take place?

5. F (fertility) factor is used in many bacterial systems for different purposes. Choose the incorrect statement with respect to the F factor.

It was identified in E. coli for catalysing genetic exchange between cells

The F factor is transferred from one cell to another via factors present outside

Cells having F factor are called as female

They are not related to BAC systems

6. Choose the correct statement for Sanger’s method of sequencing.

Use of M13 vector is made for getting double stranded DNA

The use of M13 vectors is more preferred these days

Use of dideoxynucleotide phosphate (ddNTP) is made

They are also called as chain termination methods

7. Which of the phage genes are responsible for phage excision?

int gene

both xis and int gene

recA protein

xis gene

8. Insertion vectors are a type of vectors. Choose the correct statement for this type of vector.

DNA is inserted through many restriction sites

There is an upper limit on the size of the DNA to be packaged

Lambda gt09 is an example of this type of vector

These are complex vectors

9. Choose the correct statement for the synthesis of RNA probe?

Probes are prepared for RNA transcripts which are specific for only particular strand

Double stranded DNA is only used for probe synthesis

Single stranded DNA can be used for probe synthesis

Probes are prepared for RNA transcripts which are specific for both the strands

10. A portion of phage is removed and in place of it, the DNA of interest is inserted. This type of vector is called as __________

displacement vector

transposition vector

substitution vector

insertion vector