CBSE Class 9 Biology Natural Resources Worksheet Set B

Question. The strata near to earth is
(A) Thermosphere
(B) Stratosphere
(C) Mesosphere
(D) Troposphere

Answer: D

Question. The agent/s which make/s free atmospheric nitrogen available to plants is / are
(A) lightning
(B) free living nitrogen fixing bacteria
(C) symbiotic nitrogen fixing bacteria
(D) all of these

Answer: D

Question. Earth is protected from dangerous UV radiations by
(A) Oxygen layer
(B) CO₂ layer
(C) Ozone layer
(D) Photochemical smong layer

Answer: C

Question. The environmental equilibrium is restored by
(A) producers
(B) decomposers
(C) consumers
(D) top consumers

Answer: B

Question. What is true for earth ?
(A) Earth is an open system as it receives energy
(B) Earth is a closed system as it does not take any new matter
(C) Both (1) and (2)
(D) Neither (1) nor (2)

Answer: C

Question. In sedimentary cycles, the reserve pool is
(A) air
(B) water
(C) lithosphere
(D) lithosphere and atmosphere

Answer: C

Question. Layer of ozone is present in
(A) Stratosphere
(B) Thermosphere
(C) Mesosphere
(D) Troposphere

Answer: A

Question. Land forms ______ part of earth surface
(A) 30%
(B) 36%
(C) 50%
(D) 70%

Answer: A

Question. The process of evapo-transpiration and precipitation is known as
(A) carbon cycle
(B) hydrological cycle
(C) nitrogen cycle
(D) all of these

Answer: B

Question. Composition of air remains unchanged
(A) above height of 80 km
(B) below height of 60 km
(C) below height of 80 km
(D) none of these

Answer: C

Question. Match the following
1. Matter and energy (a) Environment
2. Atmospheric vapour (b) Living crust
3. Annual precipitation (c) 4.46 × 10²⁰
4. Biosphere (d) λ 0.15 – 4µ
5. Solar radiation (e) 0.13 × 1020 G
(A) 1 (a) 2 (b) 3 (c) 4 (d) 5 (e)
(B) 1 (a) 2 (e) 3 (c) 4 (b) 5 (d)
(C) 1 (b) 2 (a) 3 (c) 4 (d) 5 (e)
(D) 1 (b) 2 (c) 3 (e) 4 (a) 5 (d)

Answer: B

Question. Match the following
1. sedimentary cycle (a) Gaseous cycle
2. water (b) soil
3. atmospheric nitrogen fixation (c) 140 – 700 mg / m² / year
4. biological nitrogen fixation (d) 35 mg / m² / year
5. biogenetic nutrients (e) essential exhaustible
(A) 1 (b) 2 (a) 3 (d) 4 (c) 5 (e)
(B) 1 (b) 2 (e) 3 (c) 4 (d) 5 (a)
(C) 1 (b) 2 (e) 3 (c) 4 (d) 5 (a)
(D) 1 (b) 2 (a) 3 (e) 4 (d) 5 (c)

Answer: A

Question. Study of Biogeochemical cycles is called Biogeochemistry. Its father is Vernadsky (= Winodgsky). It involves
(A) cycling of energy
(B) cycling of gases
(C) cycling of nutrients
(D) cycling of water

Answer: C

Question. The peak concentration of ozone above surface of earth is at
(A) 25 km
(B) 15 km
(C) 60 km
(D) 40 km

Answer: A

Question. Name two kharif crops.
Ans : Paddy and soyabean.

Question. Name two rabi crops.
Ans : Wheat and gram.

Question. Explain how fertilisers are different from manure.
Ans : Fertilisers are synthesized in factories from inorganic materials. On the other hand, manure is made from organic materials; through the process of decomposition. Excessive use of fertilisers is not good for soil and may lead to soil pollution. Use of manure is beneficial for soil.

Question. Name any three methods of irrigation and briefly describe them.
Ans : (a) Drip irrigation : In this kind of irrigation, water is supplied drop by drop near the roots of the crops or plants. They is generally used in the areas where there is a scarcity of water. However, it is very expensive.
(b) Sprinkler system : In this system, the water escapes from the revolving nozzles and is sprinkled like rain on the crops. This system is used for sandy soils and uneven land.
(c) Surface irrigation : Method to supply water to agricultural lands from well, river, dam, etc.

Question. What is mariculture?
Ans : The culture of marine fish in sea water is called mariculture.

Question. What are macro-nutrients?
Ans : The nutrients required by plants in larger quantity is called macro-nutrients. They are nitrogen, phosphorus, potassium, calcium, magnesium and sulphur.

Question. State the meaning of capture fishing and culture fishing.
Ans : Capture fishing : It is done from natural resources. Culture fishing : It is done by fish farming.

Question. Name four marine fish varieties.
Ans : Pomphret, mackerel, tuna and sardines.

Question. From where do plants get nutrients?
Ans : Air, water and soil provides nutrients to plants.

Question. Differentiate between milch and draught animals.
Ans : Milk producing animals are called mulch animals. Animals used for farm labour are called draught animals.

Question. Why should weeds be constantly removed from cultivated fields?
Ans : Weeds take up nutrients and reduce the growth of the crop.

Question. What is meant by bee-keeping? Name : (a) the variety commonly used for commercial honey production. (b) the variety having high honey collection capacity.
State how pasturage is related to honey production.
Ans : Beekeeping is the practice of rearing bee for making honey (a) Indian bee (Apis ceranaindica), (b) The Italian (Apis mellifera) bees have high honey collectioncapacity. Pasturage is the availability of flowers to the bees for nectar and pollen collection. Pasturage is related to honey production because it determines the taste of honey and the quantity of honey.

Question. Why do we eat pea and groundnut?
Ans : Pea (matar) provides us protein whereas groundnut provide us necessary fats.

Question. Mention two examples of mixed cropping.
Ans : Some combinations of mixed cropping are : wheat and mustard, groundnut and sunflower.

Question. Write four methods of weed control.
Ans : Spraying weedicide, mechanical removal, sowing of crops, intercropping and crop rotation also help in weed-control.

Question. State one importance of photoperiod in agriculture.
Ans : Photoperiod in agriculture provide adequate light for flowering.

Question. Name one micronutrient and one macronutrient which plants take from the soil.
Ans : Macronutrients are : Calcium (Ca), Magnesium (Mg) and Micronutrients are : Boron (B), Chlorine (Cl).

Question. Name the two vitamins which are added in the poultry feed.
Ans : Vitamins A and K.

Question. Organism which enriches the soil with nutrients is called biofertilizers.
(a) Write its advantage. (b) Give example.
Ans : (a) Biofertilizers are non-pollutant sources of plant nutrients. They are renewable.
(b) Example of biofertilizers are- Rhizobium, Blue green algae.

Question. A group of Science Club students made a compost pit in the school, they collected all bio-degradable waste from the school canteen and used it to prepare the compost.
(a) Name, two waste that can be used for the compost and two wastes obtained from canteen which cannot be used for the compost making.
(b) What is the other important component required for making the compost?
Ans : (a) Two waste used for compost are vegetable peels and fruit peels. Two waste materials that cannot be used as compost are polythene bags and plastic items.
(b) Bacteria and fungi present in soil are the other important component for making compost.

Question. From where do plants acquire the following nutrients?
(a) Nitrogen, (b) Hydrogen.
Ans :
(a) Nitrogen from soil,
(b) Hydrogen from waste.

Question. Name the cereals which provide us carbohydrate for energy requirement.
Ans : Cereals such as wheat, rice, maize, millets and sorghum provide us carbohydrate for energy requirement.

Question. Give technical term for milk producing females and farm labour animals.
Ans : Milk-producing females are called milch animals (dairy animals), while the ones used for farm labour are called draught animals.

Question. List two desirable traits for fodder crops.
Ans : Tallness and profused branching are the desired characteristics for producing a higher yield of fodder crops.

Question. What are the major group of activities involved for improving of crop yields?
Ans :
(i) Crop variety improvement
(ii) Crop production improvement
(iii) Crop protection improvement