Plant nutrition

Intake of nutrients into the body by an organism is called nutrition.All the nutrients required by organisms are obtained through the food they consume.Plants use inorganic minerals for nutrition. Complex interactions involving weathering of rock minerals, decaying organic matter, animals, and microbes take place to form inorganic minerals in soil. Roots absorb mineral nutrients as ions in soil water. 

Organisms differ in their modes of nutrition.There are mainly two modes of nutrition.

⚫ Autotrophic nutrition

⚫ Heterotrophic nutrition

⚫ Autotrophic nutrition

In autotrophic nutrition,the organism synthesizes its own food.Organisms which are able to synthesize their own food materials are called autotrophs.They convert carbondioxide and water into various organic compounds with the help of energy.Depending on how the plants obtain energy for converting Carbondioxide to organic compounds,they are classified as:

⭐ photo autotrophs

⭐chemo autotrophs

⭐ Photo autotrophs

All green plants are photo autotrophs.These are organisms which use energy from sunlight for the synthesis of food.Examples also include some bacteria like green sulphur bacteria, purple Sulphur bacteria.

⭐Chemo autotrophs

Organisms which use chemical energy for the synthesis of carbon compounds are called chemo autotrophs.They get energy by oxidizing simple inorganic compounds such as hydrogen,sulphur containing compounds, hydrogen sulphide and ammonia.E.g.Nitrosomonas bacteria.

⚫ Heterotrophic nutrition

Some organisms cannot synthesize their own food.They depend on other organisms for their food directly or indirectly.Organisms which are not able to synthesize their own food are called Heterotrophs.

Heterotrophic nutrition is of two types:

⭐ Saprophytic nutrition

⭐Parasitic nutrition

⭐ Saprophytic nutrition

Plants which obtain nutrition from dead or non living organic matter are called Saprophytes.e.g.monotropa

⭐ Parasitic nutrition

In parasitic nutrition,an organism derives its food from the body of other living organism(host).These plants are called parasitic plants.They have special structures which penetrate the host and absorb food,water and minerals.These special structures are called haustoria.eg:cuscuta

⭐ Symbiotic nutrition

When two organisms live together,they exchange nutrients and are benefited mutually.Such type of nutrition is called Symbiotic nutrition and the organisms are called symbiots.e.g.Rhizobium

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