Nutrition in Plants - Class 9 PDF Download

Nutrition in Plants

Every living organism needs some kind of energy and nutrient materials to ensure that the life processes go on smoothly. Moreover, this energy requirement is got from the food.  You can understand this better in animals and human beings as you see it on a daily basis. You very well know what happens if you skip breakfast or lunch! But what about plants? Do they require any nutrition at all?

Plants and their Nutrition Requirements

Plants are also living things that need some form of energy. They have cells and tissues. They also grow in size and girth. And they are the producers of the ecosystem. So, in order to synthesize food, they do have nutrient requirements. Of course, the kind of nutrient requirements varies.

This kind of nutrition in plants is called the autotrophic mode of nutrition. What does this actually mean? It means that plants have the special capability to make their own food, by using simple inorganic substances to produce organic molecules/substances. They get the energy sources from non-living things such as sun and carbon dioxide.

Plants also have chlorophyll in them, the green colour pigment. With the help of all these above factors, plants can produce simple carbohydrates. The carbohydrates thus produced are utilized by the plant and gives it energy. When there is an excess of carbohydrates in the plants, then it is stored as a reserve for later use.

Types of Autotrophic Nutrition

According to the type of energy source used, autotrophic nutrition in plants can be of two types. They are Photo-autotrophic nutrition (where sunlight is the energy source) and Chemo-autotrophic nutrition (where chemicals are the energy source).

Learn more about the Nutrition in Animals.

The Process of Photosynthesis in Autotrophs/Plants

To put it simply, plants require certain raw materials, in order to make their own food. These raw materials include carbon dioxide, water, and sunlight. Plants get water from the soil that enters through the roots. And sunlight is the source of energy. But how does carbon dioxide enter the plants? You should first understand that carbon dioxide is a gas.

You have learned in your earlier classes that plants have openings called stomata. Guard cells surround these stomata. These stomata are the openings through which carbon dioxide enters the plants. Gaseous exchange i.e. the exchange of carbon dioxide and oxygen in plants occurs through these stomatal openings.

Water is also lost through the transpiration process through these openings. And hence, when the carbon dioxide requirement is met with for photosynthesis, plants close the stoma.

The above equation shows the chemical reactions that occur during photosynthesis.

Chlorophyll is present in structures called chloroplasts. They are disc-shaped organelles that are present in the mesophyll cells of the leaves. These help in trapping the sunlight within the plant. As the carbon dioxide enters the plant through the stoma, the light energy converts into chemical energy, by the splitting of the water molecules of the plants. Simple carbohydrates are produced in this process. Oxygen is a byproduct of photosynthesis.

In this way, plants are able to take up simple inorganic substances and convert them into simple carbohydrates, to meet their nutrient requirements.