Question

In plasmid pBR322, BR stands for
A. Baculovirus and Retrovirus
B. Boyer and Reed
C. Bolivar and Rodrigues
D. Bacillus and Rhizobium

Answer 1

You can think of plasmid as a circular and small double stranded DNA that differs from the chromosomal DNA of the cells. Plasmids are thought to be occurring in bacteria and some eukaryotes too. The genes that the plasmid carry, serve as a genetic advantage to the bacteria by antibiotic resistance. Therefore, p is short for plasmid. You can relate BR as from where it is made or originated.

Complete answer:
- As mentioned above, the p stands for plasmid. BR gives information about that in which laboratory the vector is known to be constructed in.
- Baculovirus and Retrovirus: Baculovirus are known to be potent pathogens that target the arthropods and insects. Therefore this virus can make recombinant DNA proteins at a great extent. Retrovirus has RNA instead of DNA as a genetic material. This option is not true and does not relate to where the vector is constructed.
- Boyer and Reed: There is a Boyer lab which mainly studies networks of genes and proteins at a molecular level. Gene regulatory mechanisms are also explained and how any fault can lead to diseases. It has nothing to do with plasmid. So, we eliminate this option.
- Bolivar and Rodrigues: BR actually stands for Bollivar and Rodrigues. The part of the vector name is after them because they were the one who made this pBR322 cloning vector. This is the correct answer.
- Bacillus and Rhizobium: They are not what we are looking for. So we eliminate this option too.

Hence, the correct answer is option (C).

Note: The pBR322 first came into use as E.coli cloning vector. It is 4361 base pairs in length. It is very well-known as a cloning vector which is widely used for multipurpose. It has two main genes which are responsible for antibiotic resistance. One is the bla gene which is the beta lactamases and the other is AmpR which is ampicillin resistance protein. The number 322 which is used in pBR322 is mainly for differentiating this vector from the others.