Most of the plants have green pigment called chlorophyll and can make their own food. Some plants do not have chlorophyll and cannot synthesize their own food and are known as Heterotrophic plants

1. NANDITHA AKUNURI
NUTRITION IN PLANTS-2
HETEROTROPHIC NUTRITION
CLASS-VII
CBSE
CHAPTER-1

2. Heterotrophic Mode of Nutrition
Most of the plants have green pigment called chlorophyll and can make
their own food.
Some plants do not have chlorophyll and cannot synthesize their own
food and are known as Heterotrophic plants.
.

4. This Type of Nutrition can be Categorized into:
Parasitic mode of nutrition
Insectivorous mode
Saprophytic mode of nutrition
Symbiotic mode of nutrition

5. Parasitic Nutrition:
It does not have chlorophyll. It takes readymade food from the plant on
which it is climbing. The plant on which it climbs is called the host.
Since it deprives the host of valuable nutrients, Cuscuta is called the
parasite.

6. CUSCUTA
Cuscuta (dodder) is a plant that does not have chlorophyll; it sucks food
from the host plant through adventitious roots.
Cuscuta is therefore a complete parasite.

7. A parasite plant climbs on the host plant from which they get all the
food.
The host does not get any benefit from the parasite. Some examples of
parasites are Cuscuta (amarbel), hookworms, tapeworms, leeches, etc.

8. Rafflesia
Rafflesia is a parasite of the Tetra stigma plant. It is completely
dependent on its host plant for food.

10. Insectivorous Plants:
These types of plants purely depend on other insects and small animals
for their nutrition.
And these plants are called as insectivorous plants.
The insectivorous mode of nutrition is observed in plants like pitcher
plant and the Venus fly trap.

11. Pitcher plants
The pitcher-like or jug-like structure is the modified part of leaf. The
apex of the leaf forms a lid which can open and close the mouth of the
pitcher.
Inside the pitcher there are hair which are directed downwards.

12. When an insect lands in the pitcher, the lid closes and the trapped insect
gets entangled into the hair.
The insect is digested by the digestive juices secreted in the pitcher and
its nutrients are absorbed.
Such insect-eating plants are called insectivorous plants.

13. Venus Flytrap
The leaves of the Venus flytrap have stiff hair like projections on their
edges and the entire leaf is divided into two parts, with the middle acting
as a hinge.
When an insect sits on the leaf, it shuts tightly, trapping the insect inside
it.

14. Sundew Plant
Sundews are “flypaper” plants that trap prey in sticky hairs on their
leaves.
They make up one of the largest groups of carnivorous plants.
Long tentacles protrude from their leaves, each with a sticky gland at the
tip.
These droplets look like dew glistening in the sun, thus their name.

15. The glands produce nectar to attract prey, powerful adhesive to trap it,
and enzymes to digest it.
Once an insect becomes stuck, nearby tentacles coil around the insect
and smother it.

17. Have you seen see cotton-like threads spread on the piece of bread.
These organisms are called fungi.
They have a different mode of nutrition.
They absorb the nutrients from the bread.

18. Saprotrophs:
This mode of nutrition in which organisms take in nutrients from dead
and decaying matter is called Saprotrophic nutrition.
Such organisms with Saprotrophic mode of nutrition are called
saprotrophs.

19. Fungi also grow on pickles, leather, clothes and other articles that are
left in hot and humid weather for long time.
During the rainy season they spoil many things. The fungal spores are
generally present in the air. When they land on wet and warm things they
germinate and grow.

20. Symbiotic Plants
Some organisms live together and share both shelter and nutrients. This
relationship is called symbiosis.
For example, certain fungi live inside the roots of plants.
The plants provide nutrients to the fungus and, in return, the fungus
provides water and certain nutrients.

21. Lichens
In organisms called lichens, a chlorophyll-containing partner, which is
an alga, and a fungus live together.
The fungus provides shelter, water and minerals to the alga and, in
return, the alga prepares and provides food to the fungus.

22. How nutrients are replenished in the soil
So, their amounts in the soil keep on declining.
Fertilisers and manures contain nutrients such as nitrogen, potassium,
phosphorous, etc.
These nutrients need to be added from time to time to enrich the soil.
We can grow plants and keep them healthy if we can fulfil the nutrient
requirement of plants.

23. Usually crop plants absorb a lot of nitrogen and the soil becomes
deficient in nitrogen.
You learnt that though nitrogen gas is available in plenty in the air, plants
cannot use it in the manner they can use carbon dioxide.
They need nitrogen in a soluble form.

24. The bacterium called Rhizobium can take atmospheric nitrogen and
convert it into a usable form.
But Rhizobium cannot make its own food. So it often lives in the roots of
gram, peas, moong, beans and other legumes and provides them
with nitrogen.
In return, the plants provide food and shelter to the bacteria. They, thus,
have a symbiotic relationship.

25. In this chapter you learnt that most of the plants are autotrophs. Only a
few plants are parasitic or Saprotrophic. They get nutrition from other
organisms.

26. Activity- Paper Food Chain

27. THANKYOU
BY
NANDITHAAKUNURI
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