516: Consider the following statements :
If there were no phenomenon of capillarity
1. it would be difficult to use a kerosene lamp
2. one would not be able to use a straw to consume a soft drink
3. the blotting paper would fail to function
4. the big trees that we see around would not have grown on the Earth
Which of the statements given above are correct?
(a) 1, 2 and 3 only
(b) 1, 3 and 4 only
(c) 2 and 4 only
(d) 1, 2, 3 and 4
Explanation:
Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces like gravity.
The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper.
So here 1, 3 and 4 are correct.
517: The pituitary gland by virtue of its tropic hormones controls the secretory activity of other endocrine glands. Which one of the following endocrine glands can function independent of the pituitary gland ?
(a) Thyroid
(b) Gonads
(c) Adrenals
(d) Parathyroid
Explanation:
Pituitary gland controls the secretary activity of Thyroid, Adrenals, Gonads and many other glands by secreting tropic hormones (Hormones which control release of other hormones). The 'parathyroid gland' controlled by the 'calcium levels' of the blood. That's why it can function independent of the Pituitary gland.
518: Assertion (A)
Photosynthesis and vision are the phenomenon of visible light
Reason (R)
The visible light is absorbed by small particles containing chlorophylls as well as the retina of the eye
(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 incorrect but R is correct
(d) if A is correct but R is incorrect
519: The Millennium Ecosystem Assessment describes the following major categories of ecosystem services-provisioning, supporting, regulating, preserving and cultural. Which one of the following is supporting service?
(a) Production of food and water
(b) Control of climate and disease
(c) Nutrient cycling and crop pollination
(d) Maintenance of diversity
Explanation:
Services-Provisioning such as food and water;
Regulating services such as flood and disease control;
cultural services such as spiritual, recreational, and cultural benefits;
supporting services, such as nutrient cycling, that maintain the conditions for life on Earth.
Hence answer for supporting service is option (C).
520: Oxygen transportation in a human body takes place through
I. Blood
II. Lungs
III. Tissue
The correct sequence of transportation is
(a) I, II, III
(b) III, I, II
(c) II, I, III
(d) I, III, II
Explanation:
Oxygen transportation in a human body takes place in the sequence of Lungs - Blood - Tissue.