1. Autotrophic nutrition-
1. Autotrophic nutrition is the mode of nutrition in which organisms
synthesize their own organic food.
2. They use simple inorganic substances present in the surroundings
for
this process.
3. Such organisms are called autotrophs. Most of the plants are
autotrophs.
Heterotrophic nutrition-
1. Heterotrophic nutrition is the mode of nutrition in which
organisms depend on other organisms for their food. Such
organisms are called heterotrophs.
2. Different organisms use different strategies to obtain food
depending upon their body design, organization, functioning and
also availability of food material.
Eg. : (a) Fungi like yeast, mushroom and some carnivorous plants
break down the food material into simple substances outside the
body and then absorb it.
2. (b) Some organisms take in whole food and then break it down to simple
substances inside their bodies and then absorb it. Eg. human being,
cat, cow etc.
(c) Some animals and plants derive nutrition from other plants or animals
without killing them but during the process they harm the host plant
or animal. Eg. cuscuta, ticks, lice, leeches, tapeworms etc.
3.
4. 1. Ingestion : The act of taking food inside.
2. Digestion : The process of breaking down of complex organic food
into simpler soluble substances. This is done mechanically by teeth
and chemically with the help of enzymes.
3. Absorption : After digestion is completed soluble digested food is
absorbed into the blood.
4. Assimilation : The absorbed food is transported into tissues and
cells of the body where they are used to produce energy or for
growth and development or stored for future use.
5. Egestion : The undigested and unabsorbed residues of food are
thrown out of the body.
Basic steps of nutrition in all animals
