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Class VII Exercise Solutions
Nutrition in plants
Que.1.Why do organisms need to take food?
Ans. The organisms need to take
food to build their bodies, to grow, to repair damaged part of their bodies and
to obtain the energy to carry out life processes. Food provide protection
against infections.
Que.2.Distinguish between a
parasite and a saprotroph.
Ans.
|
PARASITES
|
SAPROTROPHS
|
|
Live inside the body of
host and derive the food from it
|
Feed on dead and decay
organic matter
|
|
They harm the body of host
|
They are cleaning agents
|
|
Ex.Cuscuta
|
Ex. Fungi
|
Que.3.how would you test the presence of starch in
leaves?
Ans. The presence of starch in leaves can be tested by Iodine test.
Iodine turns starch solution into blue black colour . Pour few drops of dilute
iodine solution on a boiled leaf. The leaf becomes blue black in colour which
proves the presence of starch in it.
Que.4.Give a brief description of the process of
synthesis of food in green plants.
Ans. Plants prepare their own food by the process of photosynthesis
. Leaves of the plants have green pigment called chlorophyll , which helps them
to capture the energy of the sunlight. The plants synthesise their food from
carbon di oxide and water in the presence of sunlight. This process is called
Photosynthesis.
The reaction of Photosynthesis-
Sunlight
Carbon di oxide + water ------------> Glucose
+ oxygen
Chlorophyll
Que.5.Show with the help of a sketch that the plants are
the ultimate source of food.
Ans.
Sun à Green plants à Herbivores
à Carnivores
Hence carnivores and herbivores depend on green plants for food.
Que.6. Fill in the blanks-
a.Green plants are called AUTOTROPHS since they synthesis their own food.
b.The food synthesised by the plants is stored as .. STARCH.
c.In photosynthesis solar energy is captured by the pigment called CHLOROPHYLL
d.During photosynthesis, plants take in Co2 and release
O2
Que.7.Name the following
a.A parasitic plant with yellow, slender and tubular
stem----CUSCUTA (AMARBEL)
b.A plant that has both autotrophic and heterophic mode of
nutrition PITCHER PLANT (INSECTIVOROUS
PLANT)
c.The pores through with leaves exchange gases. STOMATA
Que.8 (a).Amarbel is an example of PARASITE
(b) The plant which traps and feeds on insects
is PITCHER PLANT
(Remaining
solutions will be posted soon…)
Monday, April 6, 2020
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