606: The term "sixth mass extinction/sixth extinction" is often mentioned in the news in the context of the discussion of
(a) Widespread monoculture practices in agriculture and large-scale commercial farming with indiscriminate use of chemicals in many parts of the world that may result in the loss of good native ecosystems.
(b) Fears of a possible collision of a meteorite with the Earth in the near future in the manner it happened 65 million years ago that caused the mass extinction of many species including those of dinosaurs. .
(c) Large scale cultivation of genetically modified crops in many parts of the world and promoting their cultivation in other parts of the world which may cause the disappearance of good native crop plants and the loss of food biodiversity.
(d) Mankind's over-exploitation/misuse of natural resources, fragmentation/loss of natural habitats, destruction of ecosystems, pollution and global climate change.
607: Consider the following statements :
Chlorofluorocarbons, known as ozone-depleting substances, are used
1. in the production of plastic foams
2. in the production of tubeless tyres
3. in cleaning certain electronic components
4. as pressurizing agents in aerosol cans
Which of the statements given above is/are correct?
(a) 1, 2 and 3 only
(b) 4 only
(c) 1, 3 and 4 only
(d) 1, 2, 3 and 4
608: There are two identical red, two identical black and two identical white balls. In how many different ways can the balls be placed in the cells (each cell to contain one ball) shown below such that balls of the same colour do not occupy any two consecutive cells?
(a) 15
(b) 18
(c) 24
(d) 30
609: Consider the following statements:
1. Great Britain comprises England, Wales, Scotland and Northern Ireland.
2. England covers less than 60% of the total area of the United Kingdom.
Which of the following statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
610: In a factory, quality assurance test is conducted on various samples for a specific characteristic value of the product. The values and the number of samples are as given in the following table :
Characteristic value, X No. of Samples
10 3
11 7
12 10
13 15
14 28
15 33
16 24
17 11
18 10
19 6
20 3
Consider the following statements based on the table :
I. The probability that X ≤ 15 is 0.64.
II. The probability that 13 < X ≤ 17 is greater than 0.64.
III. The probability that X = 15 is less than 0.22.
Which of the above statements is/are not true?
(a) I alone
(b) I and II
(c) II and III
(d) I, II and III