Question

In genetic engineering, which of the following is used
A. Plasmid
B. Plastid
C. Mitochondria
D. Endoplasmic reticulum

Answer 1

Hint: Genetic engineering uses biotechnology principles and recombinant DNA technology (rDNA) to make changes in the genetic makeup of an organism. This technique is also used to check for some new genes and their functions. Many genetically modified organisms like soybean, flavr-savr tomato and golden rice are prepared by alterations in the genetic material of these.

Complete answer:
The main goal of genetic engineering in simple terms is addition of new DNA to an organism. By this, new traits can be introduced into the particular organism.
> Plasmid: It is a double stranded DNA molecule which is generally small and circular in shape. It is different from a cell’s chromosomal DNA. Plasmids are the ones that are used in genetic engineering applications. It does the process of gene transfer to bacterial cells or to cells of other organisms being plants, animals or any other form. This becomes beneficial to that particular organism for improving resistance to diseases or to enhance growth rates.

> Plastid: They are present in cytoplasm of plant cells. They are important where photosynthesis is concerned. They have pigments and their pigment type determines the cell’s color.

> Mitochondria: We are very familiar with the fact that they are the powerhouse of cell and are primarily associated with energy functions and cellular respiration.

> Endoplasmic reticulum: It is divided into smooth ER and rough ER. Endoplasmic reticulum works as a packaging system and carries materials throughout the cell.

Therefore, out of all options, Plasmid has its role in genetic engineering and not the others.
Hence, the correct answer is option (A).

Note: Plasmid have a key role to play in recombinant DNA technology process. They help bacteria to survive stress. They mimic vectors for introduction of foreign DNA into bacteria. They can have high or low copy numbers no matter if the bacterial host replicates its own DNA. They have made their place into biotechnology and genetics as important tools because of their easy manipulation and reproduction.