All Free Biology MCQs with Answers

• A. Head region
• B. Tail region
• C. Neck region
• D. Capsule region

Explanation: The phage virus uses its tail region to secrete lysozyme, an enzyme essential for breaking down the bacterial cell wall during the…

• A. Penicillin
• B. Histamine
• C. Interferon
• D. Antigens

Explanation: Interferons are a group of signaling proteins made and released by host cells in response to the presence of viruses.

• A. 50%
• B. 60%
• C. 80%
• D. 90%

Explanation: Polio, or poliomyelitis, is a disabling and potentially deadly disease. It is caused by the poliovirus.

• A. 2-6 weeks
• B. 4-10 weeks
• C. 4-20 weeks
• D. 4-26 weeks

Explanation: Hepatitis C is a viral infection that affects the liver. It causes inflammation and swelling, which damages the liver tissues over time.

• A. Hepatitis A
• B. Hepatitis B
• C. Hepatitis C
• D. Hepatitis D

Explanation: Viroids are infectious agents that consist only of naked RNA without any protective layer such as a protein coat.

• A. 1 - 2 weeks
• B. 2 - 3 weeks
• C. 3 - 4 weeks
• D. 4 - 5 weeks

Explanation: The correct answer is 2 - 3 weeks. Leaf curl disease symptoms in cotton typically become visible within this timeframe due to the…

• A. Antibodies
• B. Histamines
• C. Antigens
• D. Interferons

Explanation: The correct answer is Interferons. Interferons are proteins produced by host cells in response to viral infections.

• A. Whooping cough
• B. German measles
• C. African sleeping sickness
• D. Tay Sach's Disease

Explanation: It is also called German measles, but it is caused by a different virus than measles.

• A. Single strand RNA
• B. Double strand DNA
• C. Single strand DNA
• D. Double stranded RNA

Explanation: Influenza viruses, belonging to the Orthomyxoviridae family, have a segmented, negative-sense, single-stranded RNA genome.

• A. Hepatitis C
• B. Hepatitis B
• C. Hepatitis A
• D. Hepatitis A and B

Explanation: some viruses, such as hepatitis B and hepatitis C, can indeed cause chronic liver disease.

• A. Bacteria
• B. Algae
• C. Fungus
• D. Virus

Explanation: Meristems are devoid of viruses because they lack a vascular system. Since viruses require a host to replicate and spread, the absence of…

• A. Lysozyme
• B. Hemagglutinin
• C. Neuraminidae
• D. Integrase

Explanation: The bacteriophage is a virus that infects bacteria. It uses an enzyme called lysozyme to break down the cell wall of the bacterium it…

• A. Oral Polio vaccine
• B. Small Pox Vaccine
• C. MMR Vaccine
• D. Tetanus Vaccine

Explanation: The first scientifically approved vaccine was the smallpox vaccine. It was developed by Edward Jenner in the late 18th century.

• A. 0%
• B. 50%
• C. 75%
• D. 100%

Explanation: If the father is hemophilic (has the disease) and the mother is a carrier, the chances of the baby inheriting the disease will be 50%.

• A. 0%
• B. 50%
• C. 75%
• D. 100%

Explanation: If the father has hemophilia and the mother is a carrier, there is a 50% chance that the baby will inherit the disease.

• A. X - chromosome
• B. XX - chromosomes
• C. YY - chromosomes
• D. XY - chromosomes

Explanation: The correct answer is that a single ovum of a human being contains an X chromosome.

• A. Male
• B. Female
• C. Both male and female
• D. None of them

Explanation: Color blindness is an X-linked recessive trait, meaning it is carried on the X chromosome.

• A. X linked recessive
• B. X linked dominant
• C. Dominant autosomes
• D. Y linked inheritance

Explanation: Haemophilia is an X-linked recessive disorder, which means it is more commonly seen in males than females.

• A. Baldness
• B. Albinism
• C. None of these
• D. Myopia

Explanation: Males with higher testosterone levels have a dominant baldness gene, whereas females with lower testosterone levels have a recessive…

• A. WZ-ZZ type
• B. XY - XX
• C. X0 - XX
• D. Compound Sex

Explanation: In Drosophila, the sex determination is based on the presence of sex chromosomes.