421: Age of tree can be estimated by:
(a) Counting the number of concentric rings
(b) Counting the nodes and internodes of the trunk
(c) Measuring the girth of the tree trunk
(d) Counting the number of branches
422: A state in India has the following characteristics:
1. Its northern part is arid and semi arid.
2. Its central part produces cotton.
3. Cultivation of cash crops is predominant over food crops.
Which one of the following states has all of the above characteristics ?
(a) Tamil Nadu
(b) Gujarat
(c) Andhra Pradesh
(d) Karnataka
423: Who of the following scientists proved that the stars with mass less than 1.44 times the mass of the Sun end up as White Dwarfs when they die?
(a) Edwin Hubble
(b) S. Chandrashekhar
(c) Steven Weinberg
(d) Stephen Hawking
424: Simon Commission of 1927 was boycotted because
(a) there was no Indian Member in the Commission
(b) it supported the Muslim League
(c) Congress felt that the people of India are entitled to Swaraj
(d) there were differences among the members
425: Which of the following statements is/are correct?
Viruses can infect
1. bacteria
2. fungi
3. plants
Select the correct answer using the code given below.
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3