a) ____________ compete with main crop for nutrients.
b) Grains are separated from harvested crop by using _________ and ________.
c) Excess water in fields may cause a condition called________.
d) ___________bacteria present in the root nodules of leguminous plants helps in fixing
of atmospheric nitrogen.
e) Silk fibre is obtained from________ whereas, artificial silk is obtained by chemical
treatment of _________
f) The polymer cellulose is made up of large number of ______ units.
g) Plastics do not react with _________ and __________.
h) A micro-organism that has no cellular structure ________.
i) Tetanus disease is caused by _________.
j) __________ is used in production of vinegar from alcohol.
Answers
Answer:
a)Weeds
Ans. Weeds are unwanted plants. They grow with crops. They compete for nutrients and water with main crop.
b)threshing
Grains are separated from the harvested crops by the process of threshing. It is done manually by bitting the stalks on a rock or hard surface or by a thresher.
c)Excess water in the fields may cause a condition called water logging.
d)Rhizobium
e)wood pulp
f)D glucose units
g)Plastics do not react with food items and they are strong, light and durable. Hence they are favored for storing food.
h)Viruses
i)Tetanus is an infection caused by bacteria called Clostridium tetani. When the bacteria invade the body, they produce a poison (toxin) that causes painful muscle contractions.
j)Acetobacter.
Answer:
a) weeds
b)threshing and winnowing
c) water logging
d)rhizobium
e) silk worm and wood
f) D glucose
g)air and water
h)viruses
I) clostridium tetani
j) acetobacter