91: Phytotron is a facility to
(a) grow plants under disease-free conditions
(b) conserve endangered species of plants
(c) grow plants under controlled conditions
(d) induce mutations
92: Due to their extensive rice cultivation, some regions may be contributing to global warming. To what possible reason/reasons is this attributable ?
1. The anaerobic conditions associated with rice cultivation cause the emission of methane.
2. When nitrogen based fertilizers are used, nitrous oxide, is emitted from the cultivated soil.
Which of the statements given above is/are correct ?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Explanation:
Methane emissions from flooded rice paddies contribute to global warming just as coal-fired power plants, automobile exhausts and other sources do with the carbon dioxide they spew into the atmosphere. In fact, the report from the Intergovernmental Panel on Climate Change meeting in 2009 in Bangkok concludes that rice production was a main cause of rising methane emissions in the 20th century.
Nitrous oxide is produced naturally in soils through the microbial processes of denitrification and nitrification. These natural emissions of N2O can be increased by a variety of agricultural practices and activities, including the use of synthetic and organic fertilizers. The greenhouse gases are carbon dioxide, methane, nitrous oxide, water vapours, carbon particles etc. Growing rice has an adverse environmental impact because of the large quantities of methane gas it generates.
93: Match List I (Endocrine glands) with List II (Hormones secreted) and select the correct answer using the codes given below the Lists :
List I-------------List II
I. Gonads----------(A) Insulin
II. Pituitary--------(B) Progesterone
III. Pancreas------(C) Growth hormones
IV. Adrenal--------(D) Cortisone
Codes:
(a) I-C, II-B, III-D, IV-A
(b) I-B, II-C, III-D, IV-A
(c) I-B, II-C, III-A, IV-D
(d) I-C, II-B, III-A, IV-D
94: Consider the following statements :
1. Maize can be used for the production of starch.
2. Oil extracted from maize can be a feedstock for biodiesel.
3. Alcoholic beverages can be produced by using maize.
Which of the statements given above is / are correct ?
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1, 2 and 3
95: Insect resistant cotton plants have been genetically engineered by inserting a gene from a/an
(a) virus
(b) bacterium
(c) insect
(d) plant
Explanation:
Transgenic cotton resistant to bollworm, (Heliothis armigera), a lepidopteran insect pest was developed by inserting a toxin gene (Cry 1 AC) taken from a bacterium (Bacillus thruingiensis). This trangenic cotton was released commercially in India as Bt cotton.