UPSC 1997 Prelims Questions with Answers

Explanation

Option (c) is correct: Coronary arteries are responsible for supplying oxygen-rich blood to the heart muscle. They ensure the heart gets the necessary oxygen and nutrients for its functioning. Options (a), (b), and (d) are incorrect:

The carotid arteries are major blood vessels in the neck that supply oxygenated blood to the brain, face, and neck. The hepatic arteries supply oxygenated blood to the liver along with the hepatic portal vein. The pulmonary arteries carry deoxygenated blood from the heart to the lungs for oxygenation.

Explanation

Option (d) is correct: The recommended dietary allowance (RDA) of protein for a moderately active woman is 46 grams per day. This value is based on the average need for maintaining health, muscle repair, and proper physiological functioning. The Recommended Dietary Allowance (RDA) for protein is a modest 0.8 grams of protein per kilogram of body weight. Options (a), (b), and (c) are incorrect: 30 g, 37 g, and 40 g are below the daily requirement for a moderately active woman.

Explanation

A is matched with 5: Malaria is caused by the Plasmodium parasite which infects red blood cells. The parasite multiplies in the blood leading to symptoms such as fever, chills, and anemia. B is matched with 4: Filaria, or lymphatic filariasis is caused by parasitic worms (Wuchereria bancrofti, Brugia malayi, etc.) that infect the lymphatic system including lymph nodes. This leads to swelling and conditions like elephantiasis. C is matched with 2: Encephalitis is an inflammation of the brain which is often caused by viral infections (e.g., herpes simplex virus, Japanese encephalitis virus). It affects brain tissue and can lead to neurological symptoms. D is matched with 1: Leukaemia is a type of cancer that affects the bone marrow and blood. It involves the overproduction of abnormal white blood cells which disrupts normal blood cell production.

Explanation

An antigen is any substance (e.g., proteins, polysaccharides, or toxins) that the immune system recognizes as foreign. When an antigen enters the body, it triggers an immune response leading to the production of antibodies and activation of immune cells like T-cells and B-cells. Options (a), (b), and (d) are incorrect:

Antigens do not have a role in regulating body temperature. Lowering body temperature is typically associated with antipyretics (e.g., paracetamol) or the body>s response to infections (fever reduction). Antigens do not destroy harmful bacteria. Instead they are recognized by the immune system which then activates immune responses (e.g., antibodies, white blood cells) to neutralize or destroy pathogens like bacteria. Antigens are not used as antidotes to poison. Antidotes are specific substances (e.g., activated charcoal, atropine) that neutralize or counteract the effects of toxins or poisons.

Explanation

The genome of yeast (Saccharomyces cerevisiae) was the first eukaryotic genome to be fully sequenced. The sequencing was completed in 1996 which marked a major milestone in genomics.