Nutrition in Animals: Heterotrophism

Meaning and Types of Heterotrophism

This is a mode of nutrition whereby organisms feed on complex organic matter from other plants or animals

All animals are heterotrophs. Their mode of feeding is also said to be holozoic to distinguish it from other special types of heterotrophic nutrition, namely:

1. Saprophytism
2. Parasitism
3. Saprophytism/saprotrophysim: occurs in most fungi and some forms of bacteria
4. Saprophytes feed on dead organic matter and cause its decomposition or decay
5. Parasitism is a mode of feeding whereby one organism called the parasite feeds on or lives in another organism called the host and harms it

Modes of Feeding in Animals                               

1. Animals have developed various structures to capture and ingest food
2. The type of structures present depend on the method of feeding and the type of food
3. Carnivorous animals feed on whole animals or portions of their flesh
4. Herbiverous animals feed on plant material
5. Omnivorous animals feed on both plants and animal materials

Feeding in Mammals

1. The jaws and teeth of mammals are modified according to the type of food eaten
2. Mammals have different kinds of teeth
3. Each type of teeth has a particular role to play in the feeding process
4. This condition is described as heterodont
5. The teeth of reptiles and amphibians are all similar in shape and carry out the same function
6. They are said to be homodont