Question

Read the sources given and answer any four from the questions given below:

A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated and distinct from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules. Plasmids naturally exist in all bacterial cells but can be seen in some archaebacteria and eukaryotes. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance. The most commonly used cloning vectors are E. coli plasmids which include three functional regions: (1) an origin of replication (Ori), (2) a drug-resistance gene and (3) a region where DNA can be inserted without interfering with plasmid replication or expression of the drug-resistance gene. The replication origin (Ori) is a specific DNA sequence of 50-100 base pairs that must be present in a plasmid for it to replicate

1. Where are plasmids in bacteria located?
   1. inside the nucleus of bacteria
   2. outside the nuclear matter of bacteria
   3. as a part of chromosomal segment of bacteria
   4. on the surface of bacteria
2. How many origins of replication are present in a bacterial plasmid
   1. one
   2. two
   3. three
   4. many
3. Most bacterial plasmids have the following structure.
   1. large circular DNA molecule
   2. small circular DNA molecule
   3. large circular RNA molecule
   4. linear DNA molecule
4. Most commonly used cloning vector E. coli plasmid has the following functional regions.
   1. a drug resistance gene
   2. a region where DNA can be inserted
   3. both (a) and (b)
   4. Ori having specific RNA sequence
5. Plasmids can be seen in
   1. all bacteria
   2. all eukaryotes
   3. all viruses
   4. both (a) and (b)

Answer 1

1. outside the nuclear matter of bacteria
2. one
3. small circular DNA molecule
4. both (a) and (b)
5. all bacteria