Free Biotechnology and Health Care MCQs with Answers

21. Biotechnology is best defined as

• A. the practical use of living organisms or their products for human benefit
• B. the study of fossils
• C. the chemistry of synthetic drugs
• D. the physics of living cells

Explanation: From baking and brewing to genetic engineering, biotechnology harnesses cells and enzymes to make products and services. It is defined by application to human needs, not by any single technique.

22. Which of the following is an example of conventional biotechnology?

• A. Gene splicing in the laboratory
• B. Baking bread with yeast
• C. DNA fingerprinting
• D. Somatic cell cloning

Explanation: Humans have used microorganisms for bread, cheese and vinegar for thousands of years, long before DNA was understood. Gene splicing and fingerprinting belong to modern, molecular biotechnology.

23. Yoghurt is produced when bacteria convert milk sugar into lactic acid. This process is called

• A. photosynthesis
• B. aerobic respiration
• C. fermentation
• D. nitrogen fixation

Explanation: The bacteria ferment lactose anaerobically, and the acid they produce thickens the milk proteins. The same principle preserves many foods, from pickles to cheese.

24. A plasmid is

• A. part of the main bacterial chromosome
• B. a viral protein coat
• C. a type of ribosome
• D. a small circular DNA molecule that replicates independently in bacteria

Explanation: Plasmids carry extra genes such as antibiotic resistance and replicate separately from the chromosome. Their small size and independence make them the standard vectors of genetic engineering.

25. The single stranded ends produced by some restriction enzymes, which can base pair with matching ends on other DNA, are called

• A. telomeres
• B. sticky ends
• C. Okazaki fragments
• D. primers

Explanation: Staggered cuts leave short overhangs that anneal with complementary overhangs from DNA cut by the same enzyme, easing the joining of gene and vector. Enzymes that cut straight across leave blunt ends instead.

26. In gel electrophoresis, the smaller DNA fragments

• A. move faster and travel farther through the gel
• B. remain near the wells
• C. dissolve in the buffer
• D. become positively charged

Explanation: The gel acts as a molecular sieve, so small fragments slip through its pores more easily than large ones. Fragment size can therefore be read directly from the distance travelled.

27. DNA fingerprinting is routinely used for

• A. measuring blood glucose
• B. treating cancer
• C. establishing paternity and identifying criminals
• D. increasing crop yield

Explanation: Because the pattern of non coding repeats is unique to each individual, a sample of blood or tissue can link a person to a crime or a child to a parent. It diagnoses identity, not disease.

28. Which of the following is an application of the polymerase chain reaction?

• A. Taking X ray images
• B. Transfusing blood
• C. Dialysing a patient's blood
• D. Detecting a virus from a tiny sample of its DNA

Explanation: PCR amplifies trace DNA millions of times, making it detectable in diagnosis, forensics and research. The other options are medical procedures that involve no DNA amplification.

29. The nucleus used to clone Dolly the sheep was taken from

• A. an adult mammary gland cell
• B. a red blood cell
• C. a sperm cell
• D. an unfertilised egg's own nucleus

Explanation: Dolly proved that the nucleus of an adult, specialised cell still contains a complete genome able to direct development. A red blood cell has no nucleus, and the egg's own nucleus was removed first.

30. Golden Rice has been genetically modified to produce

• A. an antibiotic
• B. beta carotene, which the body converts to vitamin A
• C. human insulin
• D. nitrogen fertiliser

Explanation: Genes from other organisms enable the rice grain to make beta carotene, aiming to reduce vitamin A deficiency in populations that live mainly on rice. It illustrates biotechnology aimed at nutrition rather than yield.