Biotechnology Quiz: DNA, GM Crops & Gene Editing

Spoilers! These are the Starter quiz’s answers. Easy, Medium, Hard and Mixed rounds show their own answers when you finish.

1. In recombinant DNA technology, which enzyme joins DNA fragments together?

   • Restriction endonuclease
   • DNA ligase
   • DNA polymerase
   • Amylase

   Answer: DNA ligase. DNA ligase is the molecular glue that seals cut fragments. Restriction endonucleases are the molecular scissors that cut DNA at specific sequences.

2. The 'Bt' in Bt cotton stands for:

   • Bacillus thuringiensis
   • Biotech trait
   • Bollworm toxin
   • Biofortified type

   Answer: Bacillus thuringiensis. Genes (cry genes) from the soil bacterium Bacillus thuringiensis make a protein toxic to bollworms. Bt cotton was approved for commercial cultivation in India in 2002.

3. Dolly the sheep, born in 1996, was a scientific landmark because she was the first:

   • Animal born through in-vitro fertilisation
   • Transgenic farm animal
   • Mammal cloned from an adult body cell
   • Animal whose genome was edited with CRISPR

   Answer: Mammal cloned from an adult body cell. Dolly was cloned by transferring the nucleus of an adult udder cell into an emptied egg cell (somatic cell nuclear transfer) at the Roslin Institute, Scotland.

4. What is the main purpose of the polymerase chain reaction (PCR)?

   • To cut DNA at specific sites
   • To make millions of copies of a chosen DNA segment
   • To separate proteins by their size
   • To insert foreign genes into plant cells

   Answer: To make millions of copies of a chosen DNA segment. PCR amplifies a target DNA stretch through repeated heating and cooling cycles using a heat-stable polymerase. It is used in diagnosis, forensics and research.

5. Golden rice was developed to fight which deficiency?

   • Iron deficiency
   • Vitamin C deficiency
   • Iodine deficiency
   • Vitamin A deficiency

   Answer: Vitamin A deficiency. Golden rice is genetically engineered to make beta-carotene (provitamin A) in the grain, which gives it a golden colour.

6. Consider the following statements about CRISPR-Cas9: 1. It is a gene-editing tool adapted from a natural defence system that bacteria use against viruses. 2. Emmanuelle Charpentier and Jennifer Doudna received the 2020 Nobel Prize in Chemistry for developing it. Which of the statements given above is/are correct?

   • 1 only
   • 2 only
   • Both 1 and 2
   • Neither 1 nor 2

   Answer: Both 1 and 2. Both are correct. Bacteria store snippets of viral DNA and use Cas enzymes to cut matching DNA; scientists repurposed this to edit genes precisely.

7. In India, which statutory committee appraises proposals for the environmental release of genetically modified organisms?

   • ICMR
   • FSSAI
   • CSIR
   • GEAC

   Answer: GEAC. The Genetic Engineering Appraisal Committee works under the Ministry of Environment, Forest and Climate Change, under rules framed under the Environment (Protection) Act, 1986.

8. Which was the first human protein made by recombinant DNA technology to be approved as a medicine (1982)?

   • Interferon
   • Human insulin
   • Growth hormone
   • Erythropoietin

   Answer: Human insulin. The human insulin gene was put into bacteria (E. coli), which then produced insulin identical to the human hormone, replacing insulin from animal pancreas.

9. The DNA fingerprinting technique was first developed in 1984 by:

   • Alec Jeffreys
   • Kary Mullis
   • Lalji Singh
   • Har Gobind Khorana

   Answer: Alec Jeffreys. Alec Jeffreys (UK) developed it. Lalji Singh pioneered DNA fingerprinting in India at CCMB, Hyderabad; Kary Mullis invented PCR; Khorana worked on the genetic code.

10. Biofortification refers to:

    • Breeding or engineering crops so their edible parts carry more nutrients
    • Adding vitamins to packaged food after processing
    • Using microbes to clean up polluted soil
    • Spraying crops with pesticides made from bacteria

    Answer: Breeding or engineering crops so their edible parts carry more nutrients. Biofortification raises nutrients inside the crop itself, e.g. iron-rich pearl millet or zinc-rich wheat. Adding nutrients after harvest is food fortification; cleaning pollution with microbes is bioremediation.