346: Consider the following statements regarding blood pressure :
1. It is the pressure exerted by the blood on the walls of any vessel
2. It decreases in the arteries as the distance from the heart increases
3. It is lower in the capillaries than in the arteries
4. It is usually lower in women than in men.
Of these statements
(a) 1 and 4 are correct
(b) 2, 3 and 4 are correct
(c) 1, 2 and 3 are correct
(d) 1, 2, 3 and 4 are correct
347: Assertion
Comets have gaseous tails
Reason
They are very hot bodies
(a) if A and R both are correct and R is the correct explanation of A
(b) if A and R both are correct but R is not the correct explanation of A
(c) if A is correct and R is incorrect
(d) if A is incorrect and R is correct
348: Which one of the following parts of human brain is the regulating centre for swallowing and vomiting?
(a) Pons
(b) Medulla oblongata
(c) Cerebrum
(d) Cerebellum
349: Which one of the following archaeologists initially discovered the Mohanjedaro site of the Indus valley civilisation?
(a) Sujohu Marshall
(b) Daya Ram Sahni
(c) Rakhal Das Banerji
(d) Sir Mortimer Wheeler
350: Recently, there has been a concern over the short supply of a group of elements called 'rare earth metals'. Why?
1. China, which is the largest producer of these elements, has imposed some restrictions on their export.
2. Other than China, Australia, Canada and Chile, these elements are not found in any country.
3. Rare earth metals are essential for the manufacture of various kinds of electronic items and there is a growing demand for these elements.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3