NEET 2025 MCQ with Answer Explanation : Biotechnology and It’s Application.

Here below some basic MCQ’s of biotechnology and its application with answer which is explained in details.

1. Which of the following is used as a vector in gene therapy?
   a) Plasmid
   b) Liposome
   c) Virus
   d) All of the above

Answer: d) All of the above

Explanation: Gene therapy involves inserting functional genes into cells to replace or repair defective ones. Various vectors are used to carry the desired gene into target cells: Plasmids are small DNA molecules that can replicate independently.
Liposomes are lipid-based carriers that fuse with cell membranes to deliver genes.
Viruses, such as retroviruses or adenoviruses, are commonly used as vectors due to their ability to infect cells efficiently.
All of these options can be employed depending on the specific requirements of the therapy.

2. Golden rice is genetically modified to contain high levels of:
   a) Vitamin A
   b) Iron
   c) Vitamin C
   d) Protein

Answer: a) Vitamin A

Explanation: Golden rice is engineered to produce β-carotene, a precursor of Vitamin A, in the rice grains. This biofortification helps to address Vitamin A deficiency in populations dependent on rice as a staple food, particularly in developing countries.

3. Which of the following is a bio-pesticide?
   a) Bt toxin
   b) DDT
   c) Malathion
   d) Endosulfan

Answer: a) Bt toxin

Explanation: Bt toxin is produced by the bacterium Bacillus thuringiensis. This toxin is specific to insect pests and is widely used as a biological pesticide in agriculture, especially in genetically modified (GM) crops like Bt cotton. Chemical pesticides like DDT, Malathion, and Endosulfan are synthetic and can harm the environment and non-target organisms, unlike Bt toxin, which is considered eco-friendly.

4. The first transgenic cow, Rosie, produced milk rich in which protein?
   a) Casein
   b) Alpha-lactalbumin
   c) Beta-lactoglobulin
   d) Alpha-1-antitrypsin

Answer: d) Alpha-1-antitrypsin

Explanation: Rosie was a transgenic cow that produced human alpha-1-antitrypsin in her milk. This protein is used in the treatment of emphysema. The milk from Rosie was termed “humanized” because of its medicinal value and potential to benefit individuals with specific genetic disorders.

5. Cry genes used in Bt crops are obtained from which organism?
   a) Escherichia coli
   b) Bacillus subtilis
   c) Bacillus thuringiensis
   d) Pseudomonas fluorescens

Answer: c) Bacillus thuringiensis

Explanation: The Cry genes from Bacillus thuringiensis (Bt) encode for insecticidal proteins, which are toxic to insect larvae but harmless to humans and other animals. These genes are inserted into crops like cotton and maize, making them resistant to insect pests such as the cotton bollworm.

6. Which of the following enzymes is commonly used in PCR (Polymerase Chain Reaction)?
   a) Ligase
   b) Taq polymerase
   c) DNAase
   d) Helicase

Answer: b) Taq polymerase

Explanation: Taq polymerase is a heat-stable enzyme obtained from the bacterium Thermus aquaticus. It is used in PCR because it can withstand the high temperatures required for DNA denaturation and can efficiently catalyze the synthesis of DNA strands during the amplification process.

7. In RNA interference (RNAi), the target mRNA is silenced by:
   a) siRNA
   b) tRNA
   c) rRNA
   d) mRNA

Answer: a) siRNA

Explanation: RNA interference (RNAi) is a biological process where small interfering RNA (siRNA) molecules bind to complementary sequences in target mRNA, leading to its degradation or preventing its translation. This process regulates gene expression and has applications in gene silencing and therapeutic interventions.

8. The production of insulin using recombinant DNA technology was first achieved in which organism?
   a) Saccharomyces cerevisiae
   b) Escherichia coli
   c) Bacillus thuringiensis
   d) Pseudomonas putida

Answer: b) Escherichia coli

Explanation: The production of human insulin using recombinant DNA technology was first achieved in Escherichia coli (E. coli) bacteria. The human insulin gene was inserted into bacterial plasmids, and the bacteria were then cultured to produce insulin, which could be harvested and purified for medical use.

9. Which of the following is not a part of downstream processing in biotechnology?
   a) Separation
   b) Purification
   c) Fermentation
   d) Packaging

Answer: c) Fermentation

Explanation: Downstream processing refers to the steps involved after the production phase to recover and purify the biotechnological product. These include separation, purification, and packaging. Fermentation is part of upstream processing, where the product is produced, usually through microbial or cell culture systems.

10. Gene silencing in plants to combat viral infections is achieved through:
    a) Hybridization
    b) Genetic mutations
    c) RNA interference
    d) Antibiotics

Answer: c) RNA interference

Explanation: Gene silencing using RNA interference (RNAi) in plants can protect against viral infections. This method involves introducing small RNA molecules that are complementary to viral RNA, thereby degrading the viral RNA or blocking its translation, which prevents the virus from replicating.