Question

summary of nutrition in plants

Answer 1

Heterotrophic plants don't have chlorophyll, and are, therefore, unable to produce food using the process of photosynthesis. ... Some plants obtain their nutrition from decaying organic matter. They secrete digestive juices onto dead and decaying matter, and then absorb the nutrients from it.

Answer 2

All plants whether autotrophic or heterotrophic require mineral nutrition for growth and metabolism.

Mode of nutrition in plant

1) Autotrophic Nutrition

Auto means self and trophos means nourishment. Plants are called autotrophs because they make their food themselves. The making of food for themselves is called the Autotrophic nutrition. Autotrophic nutrition is found in green plants, and in some bacteria.

2) Heterotrophic Nutrition

The word Heterotrophic is the combination of two words i.e. Hetero + Trophos. Hetero means ‘others’ and ‘trophos’ means nourishment. If organisms depend on others for their food, such a mode of nutrition is called Hetetrophic Nutrition.

Animals cannot make their food themselves. They depend for food upon plants. Therefore, nutrition in animals is called Hetetrophic Nutrition. Animals are known as Heterotrophs.

3) Saprotrophic Nutrition

The uptake of nutrients by organism from dead and decaying matter in the form of solution is called the saprotrophic nutrition. The organisms which use saprotrophic mode of nutrition are called saprotrophs. For example: fungi.

The parasitic plant, cuscuta has haustoria to derive nourishment from the host plant.

A plant needs many essential nutrients for a healthy growth. They could be macro elements (required in large quantity) or microelements (required in traces).

By using the water culture technique or soil-less culture, it is possible to ascertain the importance of particular minerals.

Some elements are structural components while others are co-factors of several enzymes. They are required in various metabolic pathways and so the deficiency results in stunted growth, chlorosis, necrosis or other specific symptoms.

NPK are the three basic nutrients essential for plant growth.

The minerals are taken up by the roots through passive or active absorption.

Nitrogen, an essential nutrient cannot be taken in by the plants unless fixed into various compounds.

Nitrogen fixation is primarily by symbiotic bacteria - Rhizobium or by free living cyanobacteria.

For nitrogen fixation, a large amount of energy is derived from ATP molecules.

The dinitrogen molecule is reduced to ammonia with the help of enzyme nitrogenase.

The nitrifying bacteria convert ammonia to nitrites and then to nitrates, which are more suitably absorbed by the plants.

After the nitrates are absorbed, they are converted to ammonia with the help of nitrate reductase and nitrite reductase.

The fertilizers increase the fertility of the soil and hence are essential for the healthy growth of the plant.

NPK fertilizers are the most common fertilizers used for the crop plants.