what is mode of nutrition and ingestion of following:
Amoeba is a unicellular animal. Amoeba eats tiny (microscopic) plants and animals as food which floats in water in which it lives. The mode of nutrition in Amoeba is holozoic. The process of obtaining food by Amoeba is called phagocytosis ( 'Phagocytosis ' means 'cell feeding '). The various steps involved in the nutrition of Amoeba are: ingestion, digestion, absorption, assimilation, and egestion.
Amoeba has no mouth or a fixed place for the ingestion of food (intake of food). Amoeba ingests food by using its pseudopodia. When a food particle comes near Amoeba, then Amoeba ingests this food particle by forming temporary finger-like projections called pseudopodia around it. The food is engulfed with a little surrounding water to form a food vacuole inside the Amoeba. This food vacuole can be considered to be a 'temporary stomach ' of Amoeba
1._Ingestion: "> 1. Ingestion:In this process food is taken inside by the organisms. Excepting a few (spiders, mosquitoes, flies which suck in liquid food), all animals consume solid food. Different organs are involved in different animals for this purpose. Amoeba, a unicellular organism can take the food from surface of its body. In Hydra, the food is ingested with the help of tentacles. There are well-developed organs and methods to take food in vertebrates like lizards, birds and mammals.
The acquisition and ingestion of food is collectively termed feeding. Depending upon the nature of food, feeding may be of three types in animals.
It involves the feeding of particles which are small in comparison to the size of the organism. Paramecium, sponges, crustaceans, snails, certain fishes and birds, blue whales, etc. show microphagy. In this method water passes through filters. The contained food particles are retained and uti9lised. This method is hence, known as filter feeding.
: ">(b) Macrophagy :
It involves the feeding of particles which are large in comparison to the size of the organism, Amoeba, Hydra, certain amphibians, reptiles, fishes and birds show such type of feeding. They swallow the food as a whole without chewing.
(c) Liquid feeding:
It is also known as fluid-feeding. Leeches, tape-worm, bats, mosquitoes, be bugs, spiders, flies and mil-sucking young mammals are the examples of this type. The foods engulfed or captured by most of the mammals are mechanically broken into smaller pieces. Teeth, jaw bones and muscles help them in doing this work.
In the animals which feed on plant (herbivores) like-horse, sheep, cow, the premolar and molar teeth have well developed ridges for effective grinding of the food. In the animals which feed on other animals (carnivores) like tiger, cat, dog, leopard, the canine teeth arte sharp and large for terracing the flesh