Evolution — BIOLOGY STD 12 Science — Question

What are sacred groves and their role in biodiversity conservation?

Enumerate the complications that untreated STDs can lead to.

(a) What is a connecting link ?
(b) Which fossil animal is considered as the connecting link between reptiles and birds? Give any one character of each class found in it.

Identify 'a', 'b', 'c', 'd', 'e' and 'f' in the table given below:

No.	Syndrome	Cause	Characteristics of affected individual	Sex Male/Female/Both
1	Down’s	Trisomy of 21	‘a’ (i) (ii)	'b'
2	‘c’	XXY	Overall masculine development	‘d’
3	Turner’s	45 with OX	‘e’ (i) (ii)	‘f’

Prior to a sports event blood & urine samples of sportspersons are collected for drug tests.

1. Why is there a need to conduct such tests?
2. Name the drugs the authorities usually look for.
3. Write the generic names of two plants from which these drugs are obtained.

Narrowly utilitarian arguments are put forth in support of biodiversity conservation. Explain the other two arguments that are put forth in support of the same cause.

What are the two types of nucleases? What is their function?

Explain the greenhouse effect with reference to the gases responsible for it and their sources.

Why has the Indian Parliament cleared the second amendment of the country’s patents bill?

List any three natural world heritage sites of India.