Question

What are the necessary conditions for autotrophic nutrition and what are its by-products?

Answer 1

Nutrition is the process of taking food by an organism as well as the utilization of this food by the organisms. Organisms take food by different modes of nutrition to obtain energy and materials for growth and repair of damaged parts. There are two types of modes of nutrition in plants known as autotrophic and heterotrophic.

Complete answer:
Plants produce their food by taking raw materials from their surroundings, such as minerals, carbon dioxide and water in the presence of sunlight and hence known as autotrophs. The light energy is converted into chemical energy. Also in this nutrition organic food is made from inorganic materials.
Green plants have an autotrophic mode of nutrition. They have green pigments chlorophyll which traps sunlight energy. This energy is used in photosynthesis.
Photosynthesis: The process by which green plants, having chlorophyll, synthesize the simple sugar (glucose) from the simple raw materials water and carbon dioxide using the energy of sunlight. Oxygen is released in this process. Autotrophic plants are also known as producers.
Requirements for Photosynthesis:
Photosynthesis requires chlorophyll, carbon dioxide, water and sunlight.
1. Chlorophyll: Chlorophylls are green pigments found in photosynthetic organisms and are responsible for their green colour. Young stems and fruits may also have chlorophyll. In algae, the whole plant is green and therefore, takes part in photosynthesis.
2. Carbon dioxide: Terrestrial plants use atmospheric carbon dioxide in photosynthesis. Aquatic plants use carbon dioxide dissolved in water. Plants obtain carbon dioxide through stomata.
3. Water: Plants absorb water from soil through root hairs which is then transported up to the leaves through the stem.
4. Sunlight: Light energy helps splitting water molecules into hydrogen and oxygen. This process is called photolysis.
Carbohydrates (food) and oxygen are the by-products of photosynthesis.

Note: Like humans and animals, plants do require two types of nutrients- macronutrients and micronutrients. Macronutrients include nitrogen, phosphorus, potassium, calcium, magnesium whereas, micronutrients include boron, chlorine, copper, iron, manganese etc.