DEMO|TOPIC 02-NUTRITION -1

 

TOPIC 02-NUTRITION -1

Nutrition is the process by which an organism provides itself or is provides itself or is provided with materials necessary for energy release, growth and repair of body tissues and keeping the body in a good condition.

FOOD

Is any liquid or solid which provides the body with materials for growth and repair, energy release or keeping the body in a good (healthy) condition.

KINDS OR MODES OF NUTRITION

Basically there are two kinds of nutrition

1. AUTOTROPHIC NUTRITION

2. HETEROTROPHIC NUTRITION

AUTOTROPHIC NUTRITION

This is mode of nutrition where by organisms can make their own food from simple inorganic substance, such as carbon dioxide and water using either light energy (photosynthesis) or chemical energy (chemosynthesis). Organisms which feed by this way are known as

AUTOTROPHS

Example

1. Green plants

2. Iron bacteria and sulphur bacteria

HETEROTROPHIC NUTRITION

This is the mode of nutrition where by organisms use organic materials as the only source of food. Organisms which feed by this way are known as HETEROTROPHS. They feed on already made food.

There are three types of heterotrophic nutrition

1. Saprophytic nutrition

2. Symbiotic nutrition

3. Holozoic nutrition

1. Saprophytic nutrition

This is the mode of nutrition where by organisms feed on dead decaying bodies parts of animals or their excrete; Organisms feeding by this way are known as SAPROPHYTES

2. Holozoic nutrition

This is mode of nutrition where by organism take food by mouth. It passes through a digestive system and broken down, finally absorbed into body tissue.

FORMS OF HOLOZOIC NUTRITION

1. Herbivores – Are animals which feed on plants only Example cow, goat and zebra

2. Carnivores – Are animals which feed on flesh only e.g. lion, tiger.

3. Omnivores – Are animals which feed on varieties o food (flesh, plants, insect etc) example. Man, monkey, pig.

4. Insectivores – Are animals that feed on insects e.g. shrews, ant

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