Free Introduction to Biology MCQs with Answers

41. 9.4% of the total species known are?

• A. Protozoa
• B. Algae & Fungi
• C. Prokaryotes
• D. All of these

Explanation: Approximately 9.4% of known species are comprised of Protozoa, Algae & Fungi, and Prokaryotes combined, representing a significant portion of biodiversity.

42. Formation of insulin by factories for human use comes under:

• A. Social Biology
• B. Biotechnology
• C. Molecular Biology
• D. Microbiology

Explanation: Biotechnology involves using living organisms or their systems to develop or make products, including the production of insulin for medical purposes.

43. What is a scientific law?

• A. A uniform or constant fact of nature
• B. Virtually irrefutable theory
• C. A theory continuously supported by experimental evidence
• D. All above statement are true

Explanation: This question tests understanding of scientific terminology, essential for medical students in biochemistry and related sciences. All the above statements are true. Option D is completely correct, as it integrates the characteristics of a scientific law as a consistent, irrefutable, and evidence -supported fact. This aligns with scientific methodology critical for medical training.

44. Control by living organisms that help eliminate toxicity caused by fungicides and pesticides?

• A. Mutagens
• B. Cloning
• C. Biological Control
• D. None

Explanation: Biological control involves the use of natural organisms or processes to reduce or eliminate toxicity caused by chemicals like fungicides and pesticides.

45. What technique is used to determine the nutrient requirements of plants?

• A. Genetic engineering
• B. Bioremediation
• C. Hydroponic culture
• D. Chemotherapy

Explanation: Hydroponic culture is a technique where plants are grown in a nutrient-rich water solution, making it ideal for studying their nutrient requirements.

46. Which of the following techniques is used to preserve milk and milk products?

• A. Gene therapy
• B. Immunization
• C. Pasteurization
• D. Preventive measure

Explanation: Pasteurization is a process that heats milk to a specific temperature for a set period to kill harmful bacteria, thus preserving the milk.

47. In Chemotherapy:

• A. Cancerous parts are exposed to short-wave radiation
• B. Administering certain anti-cancerous chemicals to the patient
• C. Gene therapy
• D. All of these

Explanation: Chemotherapy is a treatment method that utilizes chemical substances, particularly anti-cancer drugs, to kill or inhibit the growth of cancer cells.

48. A technique used to repair the defective genes?

• A. Gene therapy
• B. Integrated disease management
• C. Bioremediation
• D. Cloning

Explanation: The correct answer is gene therapy. This technique involves altering the genes inside a person's cells to treat or stop disease, directly addressing genetic defects at the molecular level. In contrast, integrated disease management focuses on managing diseases using various methods without altering genetic material. Bioremediation deals with cleaning up environmental contaminants using organisms, and cloning is about creating identical copies of organisms or cells, neither of which involves repairing defective genes.

49. All of the following can treat cancer except?

• A. Radiotherapy
• B. Chemotherapy
• C. Gene therapy
• D. Antibiotics

Explanation: Antibiotics are designed to treat bacterial infections and are not effective against cancer cells. In contrast, radiotherapy and chemotherapy are established treatments that target and destroy cancer cells, while gene therapy is a promising area of research aimed at modifying genes to fight cancer.

50. Cloning could make:

• A. Multiple copies of the desired genotype
• B. Used to produce genetically identical cattle
• C. Commercial production of valuable animals
• D. All of these

Explanation: Cloning technology allows for the creation of multiple copies of a desired genotype, which is essential in various fields such as agriculture and biotechnology. It can be used to produce genetically identical cattle, ensuring that desirable traits are consistently passed on. Additionally, cloning is employed in the commercial production of valuable animals, maximizing the economic benefits of certain genetic characteristics.