On the topic - Modes of Nutrition

1. Biology presentation
By Juvraj Singh (7th A)

2. Heterotrophic Mode Of Nutrition
• There are some plants which do not have chlorophyll. They cannot
synthesis their food. Like humans and animals, such non-green
plants depend on the food produced by other green plants. This is
called heterotrophic mode of nutrition.

3. Saprotrophic Nutrition
• The mode of nutrition in which the non-green plants obtain their
nutrients from dead and decaying organic matter of plants and
animals is called saprotrophic nutrition. Plants which use
saprotrophic nutrition are called saprophytes. For example, Indian pipe,
Coral root, Some fungi and bacteria etc.
• a) Indian Pipe b) Coral Root

4. Parasitic Nutrition
• Cascuta has a special structure called haustoria which pierces into the
plant’s body on which it climbs for absorption of ready-made food. The
mode of nutrition in which some plants live in or on the body of
another living organisms and derive their ready-made food from
them is called parasitic nutrition. The plant Cascuta which obtains
their ready-made food is called a parasite and the oraganism from whose
body the the food is obtained is called the host.
Cascuta (a total parasite)

5. Total And Partial Parasite
• Parasites may be total or partial. Cascuta is a total parasite.
Mistletoe is an example of partial parasite. It has green leaves. These
green leaves can make their own food. But this plant receives water
and minerals from the host plant (on which it grows) to synthesis
food.
Mistletoe (Partial Parasite)

6. Symbiosis
• A Lichen is actually composed of two distinct organisms, algae and
fungi, which live and work together. The algae (having chlorophyll)
can make their own food and the fungi share the food made by the
algae. The fungi in return, provide protection, water and minerals to
the algae. The association in which two different types of living
organisms live and work together for their mutual benefits is called
symbiosis. Lichens sow symbiosis.
Lichen

7. Symbiosis in Leguminous plants
• Similarly, Rhizobium bacteria live in the nodules of the roots of
leguminous plants like pea and gram and provide them nitrogen in a
soluble form. In return, the plants provide food and shelter to the
Rhizobium bacteria. So, both oraganisms benefit each other.
Root nodules in leguminous plants.

8. The End