Free Biotechnology MCQs with Answers

31. The first genetically engineered product approved for human medical use was

• A. Bt cotton
• B. Golden Rice
• C. Dolly the sheep
• D. human insulin produced by bacteria

Explanation: Approved in the early 1980s, bacterial human insulin transformed diabetes care and opened the era of biopharmaceuticals. Crops and cloned animals came later and are not medicines.

32. Gene therapy has been used in attempts to treat

• A. broken bones
• B. malaria
• C. severe combined immune deficiency, SCID
• D. appendicitis

Explanation: By inserting a working copy of the defective gene into the patient's cells, gene therapy targets single gene disorders such as SCID. Injuries and infections are treated by other means.

33. Embryonic stem cells are described as pluripotent because they

• A. can divide only once
• B. can differentiate into any cell type of the body
• C. produce blood cells only
• D. never divide

Explanation: Pluripotency means the ability to become nerve, muscle, blood or any other tissue, which is why these cells hold regenerative promise. Adult stem cells are usually more restricted in their options.

34. A practical use of monoclonal antibodies is

• A. treating some cancers and detecting pregnancy
• B. sterilising surgical instruments
• C. filtering blood in dialysis
• D. grinding food in digestion

Explanation: Because each monoclonal antibody recognises one target, it can mark cancer cells for destruction or detect the hormone hCG in pregnancy tests. Their value lies in precision, not in physical processes.

35. A goat engineered to secrete a human protein in its milk is an example of

• A. a clone
• B. a hybrid
• C. a transgenic animal
• D. a mutant

Explanation: The animal carries a gene from another species and expresses it in milk, from which the medicine is purified. Cloning copies an existing genome, whereas transgenesis introduces a new gene.

36. Which of the following is an advantage of genetically modified crops?

• A. They never cross breed with wild plants
• B. They eliminate all insects from the farm
• C. They require no sunlight
• D. They can resist pests or herbicides, reducing the need for sprays

Explanation: Bt crops make their own insecticidal protein and herbicide tolerant crops simplify weed control, both cutting chemical inputs. The absolute claims in the other options are false and designed to tempt.

37. Cloning is the production of

• A. organisms genetically identical to the original
• B. hybrids between two species
• C. organisms with random mutations
• D. gametes in the laboratory

Explanation: A clone shares the exact nuclear genome of its source, whether produced by cuttings, bacteria dividing or nuclear transfer. Hybrids and mutations increase variation, the opposite of cloning.

38. The Human Genome Project determined the sequence of roughly how many base pairs?

• A. 3 million
• B. 3 billion
• C. 300 thousand
• D. 3 trillion

Explanation: Completed in 2003, the project read about three billion base pairs spanning the human genome's roughly 20,000 to 25,000 genes. Confusing billions of bases with thousands of genes is the trap.

39. Genetically engineered vaccines are considered safer than older vaccines because they

• A. contain live pathogens
• B. are never tested before use
• C. contain only specific proteins of the pathogen, not the whole organism
• D. provide immunity without any immune response

Explanation: Recombinant vaccines such as hepatitis B present one safe protein to the immune system, removing any risk of the disease itself. An immune response is still required; that is how the memory is made.

40. The antibiotic resistance gene carried on a plasmid vector serves to

• A. cut the DNA at specific points
• B. digest the bacterial cell wall
• C. colour the bacterial colonies
• D. identify the bacteria that have successfully taken up the plasmid

Explanation: Only bacteria carrying the plasmid survive on antibiotic containing medium, so the marker selects the transformed cells. The cutting is done by the restriction enzyme before the plasmid enters the cell.