All Free Biology MCQs with Answers

1291. Which statement is incorrect for pasteurization?

• A. It is used to preserve yogurt and milk
• B. It was developed by Louis Pasteur.
• C. It involves heating the substance at high temperature for just few sec.
• D. It can be used to preserve vegetables and meat.

Explanation: Pasteurization is mainly used for liquids such as milk and fruit juice, using controlled heating to destroy harmful microorganisms without completely sterilising the product. Vegetables and meat are generally preserved by methods such as refrigeration, freezing, drying, canning or irradiation, so option d is the incorrect statement. Option c can describe high-temperature short-time pasteurization, although not every pasteurization method uses only a few seconds.

1292. Astronauts may use which technique to grow fruits and vegetables ?

• A. Tissue culture techniques
• B. Cloning
• C. Pasterisation
• D. Hydroponic culture technique

Explanation: Hydroponic culture grows plants without soil by supplying water, mineral nutrients and suitable environmental conditions directly to the roots, making it useful in controlled spacecraft systems. Tissue culture and cloning produce plants from cells or tissues, but they are not the technique primarily meant for growing crops in space.

1293. Breeders have developed new and better varieties of food items by using which technique?

• A. Pasteurization
• B. Hydroponic culture technique
• C. Genetic engineering
• D. Biological control techniques

Explanation: Genetic engineering allows breeders to alter specific genes or introduce useful genes, producing organisms with desired traits such as improved yield, nutrition or resistance to pests. Pasteurization preserves food after production, whereas hydroponics changes the growing system and does not directly create new inherited varieties.

1294. Sythetic insulin from pork was formed by which technique?

• A. Biotechnology
• B. Social biological techniques
• C. Parasitology
• D. Both a and c

Explanation: Insulin production uses biotechnology because genes and biological systems are manipulated to produce a medically useful hormone, historically including insulin related to porcine insulin. Students may choose parasitology because it is another biological field, but parasitology deals with parasites rather than producing therapeutic proteins.

1295. Crop rotation helps in______________?

• A. Growth of pathogens
• B. Soil Infertility
• C. Slowing of crops growth
• D. Eradication of disease

Explanation: Crop rotation interrupts the continuous presence of crop-specific pathogens by changing the host plant grown in a field, so disease-causing organisms may fail to complete their life cycles. Students may choose soil infertility because repeated cultivation can reduce soil quality, but rotation generally helps maintain fertility rather than cause infertility.

1296. The Science of growing terrestrial plants in an aerated solution is_________?

• A. Hydrodynamics
• B. Hydroponics
• C. Hydrotonics
• D. None of them

Explanation: Hydroponics is the cultivation of plants without ordinary soil, using an aerated nutrient solution that supplies water and mineral ions to the roots. Students may choose hydrodynamics because it concerns moving fluids, but it is not the name of this plant-growing method.

1297. The first antibiotic to be discovered was_____________?

• A. Penicillin
• B. Cephalosporin
• C. Amino glycosides
• D. Erythromycin

Explanation: Penicillin, discovered by Alexander Fleming in 1928, is conventionally regarded in basic biology as the first discovered antibiotic and was later developed for medical use. Students may choose cephalosporin because it is also an antibiotic, but it was discovered later than penicillin.

1298. Malaria is associated with___________?

• A. Culex Mosquito
• B. Culiesta Mosquito
• C. Anopheles Mosquito
• D. Culex & Anopheles Mosquito

Explanation: Malaria is caused by Plasmodium parasites, which are transmitted to humans mainly through the bite of an infected female Anopheles mosquito. Culex mosquitoes transmit diseases such as filariasis and Japanese encephalitis, so students may choose option d by incorrectly assuming that both common mosquito genera transmit malaria.

1299. The branch in which organism's life cycle, mode of transmission and interaction with their hosts are studied is:

• A. Anatomy
• B. Physiology
• C. Parasitology
• D. Social Biology

Explanation: Parasitology is the branch of biology that studies parasites, including their life cycles, modes of transmission, and interactions with hosts. Anatomy studies structure and physiology studies function, while social biology concerns interactions among organisms or people rather than host-parasite relationships. Students may choose physiology because a parasite affects host functions, but the complete subject described is parasitology.

1300. The branch of Biology which deals with the use of data and techniques of engineering & technology concerning living organisms is:

• A. Human Biology
• B. Environmental Biology
• C. Genetics
• D. Bio-technology

Explanation: Biotechnology applies biological knowledge together with engineering and technological techniques to living organisms, cells, or their products. Genetics focuses specifically on heredity and variation, whereas human and environmental biology are broader fields. Students may choose genetics because it is used in biotechnology, but it is only one contributing area.