1. which is not a method for the conservation of natural resources? encourage the use of organic fertilizers to avoid wastage of energy take part in deforestation 2. name the term that can collectively refer to consist of all living and non-living things that surround an organism resource environment value 3. from the following which one can be described as the best example for having an economical value a beautiful sunset good weather resources like iron and manganese
Answers
Answer:
12. Seed drill, because it is a modern agricultural implement unlike
the others which are all traditional tools.
13. The field will be watered, tilled and ploughed before sowing seeds.
14. (i) False: Apart from good quality seeds, using appropriate
agricultural practices are important for getting higher
yield.
(ii) False: It actually enriches the soil.
(iii) False: Some crop plants need transplantation.
(iv) False: Rhizobium (bacteria) present in the cells of root
nodules of leguminous, plants fix nitrogen.
(v) True.
15. October to March.
16. Loosening the soil/maintaining high moisture levels in soil.
SHORT ANSWER QUESTIONS
17. Kharif : Rice or Soyabean, Rabi : Pea or Wheat.
Pea/Soyabean are legumes that will fix nitrogen with the help of
Rhizobium.
Answers
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ANSWERS 111
18. (i)-c; (ii)-a; (iii)-b; (iv)-d
19. Crops cultivated without using any chemicals like fertilisers,
pesticides, weedicides etc. are called organic foods.
20.
Living : Seed, Earthworm, Rhizobium, Microbes, Ox
Non living: Plough, Urea, NPK, Manure, Hoe
21. (a) Seed drill.
(b) The advantages are,
(i) seeds are sown at a uniform distance and depth to avoid
over crowding.
(ii) after sowing, seeds are covered by soil which prevent them
from being eaten by birds.
(iii) It saves time and labour.
22. (a) Animal husbandry.
(b) Animals are provided with proper food, shelter and care.
23. Khariff : Maize , Paddy, Groundnut, Cotton.
Rabi : Mustard, Pea, Wheat, Gram.
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112 EXEMPLAR PROBLEMS
LONG ANSWER QUESTIONS
24. (i) He did not use good quality seeds.
(ii) His field was not well irrigated.
(iii) Manures/fertilisers were not properly applied.
(iv) Weeds were not removed. More can be added to the list.
25. The following items are required – seeds and seedlings of vegetable
plants from nursery, kitchen waste, water.
Steps for raising the garden:
1. Kitchen waste will be collected and composted in a pit.
2. A patch of land will be identified for the garden.
3. Soil will be dug up and levelled with the help of a spade.
4. Sowing of seeds / transplanting of seedlings.
5. Select seeds/seedlings as per the season. Water the plants
regularly with a water-can.
6. Compost will be applied.
7. Weeds will be removed periodically with the help of Khurpi.
26. (a) Rainy season
(b) Seeds are first grown in a nursery and later seedlings are
transplanted in the field.
(c) Grains are sun dried to reduce the moisture content and
later stored in jute bags or grain silos.
27. (i) SILOS (ii) THRESHING (iii) IRRIGATION (iv) RIVER
Activity carried out in fields after maturation of crop-Harvesting
28. (i) Use of fertilisers and weedicides are hazardous to
environment. Tractor causes air pollution.
(ii) Modern agricultural implements saves on both time and
labour as compared to traditional equipments.
(iii) An example of a weedicide is 2, 4–D. Farmers should cover
their mouth and nose while spraying weedicides as they
can cause health hazards.
29. Students may come up with practical solutions during the course
of discussion.
30. Tilling and ploughing, sowing, manuring, irrigation, de–weeding,
harvesting.
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ANSWERS 113
Chapter 2
MULTIPLE CHOICE QUESTIONS
1. b 2. b 3. c 4. d
5. b 6. b 7. b
VERY SHORT ANSWER QUESTIONS
8. (a) antibodies (c) Anthrax
(b) tuberculosis (d) fermentation
9. (a) Preservatives (c) Carrier/vector
(b) Rhizobium (d) Antibiotics
10. (a)-(iii); (b) (ii); (c)-(iv); (d)-(i)
11. Baking bread/manufacture of alcoholic drinks
12. Fermentation
13. Nitrogen
14. Tuberculosis is an air-borne disease which easily spreads when
the infected person coughs.
15. If the child is suffering from diarrhoea, the orally given vaccine
may be excreted out because of frequent motions.
16. Oil prevents bacteria from attacking the pickle and spoiling it.
SHORT ANSWER QUESTIONS
17. (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)
18. Friendly Harmful
Yeast Malarial parasite
Lactobacillus Bread mould
Rhizobium Bacillus anthracis
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114 EXEMPLAR PROBLEMS
19. The probable reason is that the chaat was contaminated by
pathogenic microbes due to unhygienic conditions near the shop
or the utensil used for serving could have contaminated.
20. The ‘unused kneaded flour’, if left in warm conditions, gets
infected by microbes which cause fermentation and spoils the
flour. The pooris would remain in relatively good condition
because they were deep fried in heated oil that kills microbes.
21. (a) Polio/Chicken Pox/Influenza
(b) Virus can reproduce only inside the cells of host.
LONG ANSWER QUESTIONS
22. (a) Yellow vein mosaic of lady’s finger/okra
(b) Virus
(c) The disease spreads from one plant to another through
insects.
(d) (i) Citrus canker caused by bacteria (ii) Rust of wheat caused
by fungus or any other disease