FREE NEET Biology Practice MCQ Test: Human Health And Diseases Exercise 3 Questions Answers With Detailed Explanations [PDF]

Answer: (d)

Widal test (developed by G.F.I Widal) is an agglutination test for the presence of antibodies against the Salmonella organism that cause typhoid fever. It is used to diagnose the presence of the disease in a patient.

Answer: (d)

Answer: (d)

Leukemia is a group of cancers that usually begins in the bone marrow and results in high numbers of abnormal white blood cells. These white blood cells are not fully developed and are called blasts or leukaemia cells. Symptoms may include bleeding and bruising problems, tiredness, fever and an increased risk of infections. These symptoms occur due to a lack of normal blood cells.

Answer: (a)

Ringworm is an infectious disease. It is a skin infection caused by a fungus that can affect the scalp, skin, fingers, toes, nails or foot.

Answer: (a)

Man acquires infection of Ascaris by directly ingesting Ascaris eggs, containing the infective second stage larva, with contaminated food or water. Life cycle of Ascaris is monogenetic. There is no vector or intermediate host.

Answer: (b)

Answer: (c)

Answer: (b)

Interferon is a protein releases usually in response to the entry of a virus. It has the property of inhibiting virus replication. Interferon prevents the virus from reproducing within the infected cells and can also induce resistance to the virus in other cells.

Answer: (b)

Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Virus infected cells secrete proteins called interferons, which protect non-infected cells from further viral infection.

Answer: (c)

Macrophages are known as 'HIV' factory in a person infected by AIDS. This can be explained as after entering the body of a healthy person, the HIV enters into macrophages where RNA genome of the virus replicates to form viral DNA with the help of the enzyme reverse transcriptase.

Answer: (b)

Answer: (a)

Answer: (d)

All the options given are diseases with their associated vector which transmit the respective diseases.

Leishmaniasis, also called kala azar is caused by Leishmania donovani. It is spread by sand fly (Phlebotomus) and characterised by enlarged spleen and liver with high fever.

Sleeping sickness is caused by a protozoan Trypanosoma gambiense. Filariasis is caused by worm Wuchereria bancrofti. Dengue fever is caused by arbo virus.

Answer: (c)

Answer: (d)

Answer: (c)

Answer: (d)

Answer: (d)

When the $T_{H}$ cell binds antigen being presented on a macrophage, it secretes cytokines which activate itself and B cells.

Answer: (d)

Answer: (a)