Prelims · Science & technology · 32 questions

Human body, health & diseases

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Prelims 2024 · Q33

Easy

Which one of the following is synthesised in human body that dilates blood vessels and increases blood flow?

Answer & explanation

Answer: (a) Nitric oxide

Nitric oxide (NO) is made by the cells lining our blood vessels (the endothelium). It diffuses into the surrounding smooth muscle and makes it relax, which widens the vessels and lets more blood flow; its discovery as a signalling molecule won the 1998 Nobel Prize in Physiology or Medicine.

✓ (a) Furchgott, Ignarro and Murad showed that the 'endothelium-derived relaxing factor' that dilates blood vessels is nitric oxide; heart drugs such as nitroglycerin work by releasing NO.
✗ (b) Nitrous oxide (N2O) is 'laughing gas', used as an anaesthetic and a greenhouse gas; the body does not make it to control blood vessels.
✗ (c) Nitrogen dioxide (NO2) is a brown, toxic air pollutant from vehicle exhausts and combustion that irritates the lungs; it is not a body signal.

Remember · Nitric oxide (NO) = body's own vasodilator, made by the endothelium; 1998 Nobel (Furchgott, Ignarro, Murad). Nitroglycerin relieves angina by releasing NO. N2O = laughing gas.

📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 11 (practise this chapter)

Sources

The Nobel Prize in Physiology or Medicine 1998: press release ↗ “He concluded that blood vessels are dilated because the endothelial cells produce an unknown signal molecule that makes vascular smooth muscle cells relax. … He performed a brilliant series of analyses and concluded in 1986, together with and independently of Robert Furchgott, that EDRF was identical to NO.”
NCERT Class 11 · Fundamentals of Physical Geography, Chapter 11 “The primary GHGs of concern today are carbon dioxide (CO2), Chlorofluorocarbons (CFCs), methane (CH4), nitrous oxide (N2O) and ozone (O3).”

Question and answer: UPSC's official GS Paper I (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2024 · Q99

Medium

With reference to the ‘Pradhan Mantri Surakshit Matritva Abhiyan’, consider the following statements:

1.This scheme guarantees a minimum package of antenatal care services to women in their second and third trimesters of pregnancy and six months post-delivery health care service in any government health facility.
2.Under this scheme, private sector health care providers of certain specialities can volunteer to provide services at nearby government health facilities.

Which of the statements given above is/are correct?

Answer & explanation

Answer: (b) 2 only

Only statement 2 is correct: PMSMA encourages private doctors to volunteer at government health facilities. Statement 1 goes wrong because PMSMA is an antenatal (before-birth) care programme run at designated government facilities; it has no six-month post-delivery package.

✗ 1. PMSMA guarantees a minimum antenatal package for women in the 2nd/3rd trimesters at designated government facilities, on the 9th of every month. Post-delivery care for six months is not part of it, and it is not offered at any government facility.
✓ 2. The programme has a systematic approach to engage the private sector, motivating private practitioners to volunteer for the campaign at government health facilities.

Remember · PMSMA (2016): free antenatal check-up on the 9th of every month for 2nd/3rd-trimester women at designated government facilities; private doctors volunteer.

Sources

About the scheme, Pradhan Mantri Surakshit Matritva Abhiyan (MoHFW) ↗ “PMSMA guarantees a minimum package of antenatal care services to women in their 2nd / 3rd trimesters of pregnancy at designated government health facilities … The programme follows a systematic approach for engagement with private sector which includes motivating private practitioners to volunteer for the campaign”

Question and answer: UPSC's official GS Paper I (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

The same topic in Mains

Science & technology in everyday lifeGS 3 syllabus

Read it in NCERT

Class 11 Fundamentals of Physical Geography, Chapter 11cited in 1 explanation