CBSE Class 8 - Science Periodic Assessment (2017) - Crop Production and Microorganisms (#cbseNotes)

CBSE Class 8 - Science Periodic Assessment (2017) - Crop Production and Microorganisms 

Sample Question Paper with some answers given below.







Answers:

1. (a) natural
    (b) Weedicides
    (c) Yeast
    (d) five

2. (a) Lactobacilus, a bacteria converts sugars and milk into lactic acid (curd) by fermentation.

    (b) Loosens the soil, improves air circulation in soil so that roots can respire easily and ehnances water holding capacity of the soil.

    (c) Earthworms create burrows which make soil porous and air rich. Their casts (faeces) has organic matter thus making the soil more fertile.

    (d) Ambient temperature, moisture, slightly acidic food.

    (e) drip irrigation, sprinkler irrigation.  Drip irrigation consists of  tubing which carry water. Water is released directly into the ground (near to roots). It is an efficient water delivery system.


3.
   i. Preparation of soil
  ii. Ploughing
  iii. Manuring
   iv.   Irrigation
   v.  Harvesting
  vi. Threshing
  vii. Winnowing
  ix. Storage