Available Answers

1. 1.

   Choose and write the correct answer (MCQs):

   1. Animal husbandry deals with ____________: 
      1. poultry 
      2. fisheries 
      3. apiculture 
      4. all domestic animals
   2. The crops that are harvested by March and April are __________ :
      1. rabi crops
      2. medicinal crops
      3. kharif crops 
      4. fibre crops
   3. The monomer of PVC is :
      1. poly styrene
      2. PAN
      3. neoprene
      4. poly vinyl chloride
   4. Natural rubber is a polymer of:
      1. butadiene
      2. ethylene
      3. styrene
      4. isoprene
   5. ___________ is a combustible substance :
      1. stone 
      2. cement 
      3. kerosene
      4. pollution 
   6. The ignition temperature of white phosphorus is __________.
      1. 40°C
      2. 38°C
      3. 35°C
      4. 50°C
   7. Animal cell do not have:
      1. nucleus
      2. cell membrane
      3. cell wall
      4. mitochondria 
2. 2.

   Fill in the blanks:

   1. ___________ is used to make bread, pastries and cake.
   2. Penicillin is obtained from the fungus ___________.
   3. ____________ are not malleable.
   4. Non-metals are generally bad conductors of ________ and _________.
   5. IVF stands for _________.
   6. Fusion of gametes gives rise to a single cell called ________.
   7. The force of ________ is the responsible for changing the state of motion.
3. 3.

   Write T for true or F for false:

   1. Diseases like cholera, tuberculosis and typhoid are caused by protozoans.
   2. Diarrhoea and gastroenteritis are intestinal disorders.
   3. Zinc is used in making concave mirrors in astronomical telescopes.
   4. Chlorine is used to kill bacteria in drinking water.
   5. A Biosphere Reserves is an international designation for conversation.
4. 4.

   What is irrigation? Mention three methods of irrigation which are commonly practised in India.
5. 5.

   How does cross-breeding helps in improving the varieties of crops?
6. 6.

   Describe the various types of combustion.