In genetic engineering, a DNA segment (gene) of interest is transferred to the host cell through a vector. Consider the following four agents (A-D) in this regard and select the correct option about which one or more of these can be used as a vector/vectors:

A.	a bacterium	B.	plasmid
C.	plasmodium	D.	bacteriophage

Options:

1.	(A) only	2.	(A) and (C) only
3.	(B) and (D) only	4.	(A), (B) and (D) only

Which one of the following techniques made it possible to genetically engineer living organisms?

1. Hybridization

2. Recombinant DNA techniques

3. X-ray diffraction

4. Heavier isotope labelling

Which of the following are used in gene cloning:

1. Lomasomes

2. Mesosomes

3. Plasmids

4. Nucleoids

In genetic engineering, the antibiotic-resistance gene is used:
1.  To select healthy vectors
2.  As sequences from where replication starts
3.  To keep the cultures free of infection
4.  As selectable markers

Genetic engineering involves:
1. Use of restriction endonuclease on bacterial DNA and formation of new traits
2. Use of Ligase for cutting DNA
3. Developing instruments
4. Use of statistic in genetics

Restriction endonucleases:

Which of the following enzymes are used to join bits of DNA:

1. Ligase

2. Primase

3. DNA polymerase

4. Endonuclease

Manipulation of DNA in genetic engineering became possible due to the discovery of:

1. Restriction endonuclease

2. DNA ligase

3. Transcriptase

4. Primase

In Lederberg's replica plating experiment, what shall be used to obtain streptomycin resistant strain?
1.  Minimal medium and streptomycin
2.  Complete medium and streptomycin
3.  Only minimal medium
4.  Only complete medium

Select the correct statement from the following: