Practice free Zoology NEET multiple-choice questions online with instant answers and detailed explanations. No login required.
What is an allergy?
The text defines allergy as 'The exaggerated response of the immune system to certain antigens present in the environment is called allergy.'
Which type of antibodies are produced in response to allergens?
NCERT mentions, 'The antibodies produced to these [allergens] are of IgE type.'
Which chemicals are released from mast cells, causing the symptoms of allergic reactions?
The text states, 'Allergy is due to the release of chemicals like histamine and serotonin from the mast cells.'
Which of the following describes the key characteristic of AIDS that differentiates it from a congenital disease?
The NCERT text states, 'Acquired Immuno Deficiency Syndrome (AIDS) means deficiency of immune system, acquired during the lifetime of an individual indicating that it is not a congenital disease.' This directly implies it is acquired later in life, rather than being present from birth.
AIDS was first reported in which year and has since killed approximately how many people globally?
According to the NCERT text, 'AIDS was first reported in 1981 and in the last twenty-five years or so, it has spread all over the world killing more than 25 million persons.'
The Human Immunodeficiency Virus (HIV) belongs to which group of viruses, and what is the nature of its genome?
The NCERT states, 'AIDS is caused by the Human Immuno deficiency Virus (HIV), a member of a group of viruses called retrovirus, which have an envelope enclosing the RNA genome.'
Which of the following is NOT a common mode of transmission for HIV infection?
The NCERT text lists transmission by 'sexual contact with infected person, by transfusion of contaminated blood and blood products, by sharing infected needles as in the case of intravenous drug abusers and from infected mother to her child through placenta.' It also explicitly states, 'It is important to note that HIV/AIDS is not spread by mere touch or physical contact; it spreads only through body fluids.' Sharing food does not involve body fluid exchange.
Upon entering the human body, HIV initially targets which specific immune cells?
The NCERT states, 'After getting into the body of the person, the virus enters into macrophages where RNA genome of the virus replicates to form viral DNA with the help of the enzyme reverse transcriptase.'
What is the role of macrophages in HIV infection, as described in the NCERT text?
According to the NCERT, 'The macrophages continue to produce virus and in this way acts like a HIV factory.'
The progressive decrease in which type of immune cell is directly responsible for the immunodeficiency observed in AIDS patients?
The NCERT text clearly states, 'The progeny viruses released in the blood attack other helper T-lymphocytes. This is repeated leading to a progressive decrease in the number of helper T-lymphocytes in the body of the infected person.'
Ready to ace NEET?
Free access · No credit card required
Yes. You can attempt every Zoology question on this page for free without logging in, and check the correct answer with a detailed explanation instantly.
No account is required to attempt questions and view answers. A free account adds bookmarks, personal notes, and progress tracking.
The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.