Nutrition in Plants Class 7 Science Notes - Chapter 1
Introduction to Nutrition in Plants
Living and Non-Living Organisms
Living organisms like groups of people, plants and animals need food to survive and exist.
Living organisms reproduce, reply to the environment and also adapt.
Living organisms respire and excrete in addition
Cells
Cells are tiny units that help form up a living organism. Hence they're also called building blocks of an organism.

A cell is constituted of three major parts :
A thin outer layer called the semipermeable membrane.
A spherical structure located at the centre of the cell called a nucleus.
A jelly-like substance that surrounds a nucleus called the cytoplasm.
Single and Multi-Cellular Organisms
Organisms that are made of only one cell are called single-celled or Unicellular organisms. E.g. Amoeba
Organisms with over one cell in their body are called multicellular organisms.
All groups of people, plants and animals are multicellular organisms.
Nutrition
Nutrition is that the mode of taking food by an organism and its utilisation by the body.

Nutrition is extremely important because the nutrients from the food consumed enables living organisms to create their bodies and grow.
Nutrition helps to repair damaged parts and organs.
Nutrition also provides energy for completing various functions.
Autotrophs and Heterotrophs
Organisms that make food themselves are called autotrophs.

Plants are an example of autotrophs as they create their own food using greenhouse emission, water and light-weight energy.
Organisms that depend upon others and typically soak up ready-made food made by the autotrophs are called heterotrophs.

Animals and groups of people are an example of heterotrophs as they depend upon plants in some ways for his or her food.
Photosynthesis
Photosynthesis is that the process of synthesis of food by green plants.

This process usually takes place within the leaves of plants.
The process requires chlorophyll (green coloured pigment), sunlight, greenhouse emission and water.
Organelles
Organelles are tiny cellular structures inside a cell and perform specific functions that are important for the cell.
They are found within the cytoplasm of a cell.
E.g. Chloroplast is that the cell organelle that carries out photosynthesis.
Chloroplasts
The chloroplast may be a form of organelle that exists in plants.
These organelles contain chlorophyll, the green coloured pigment that's to blame for completing the method of photosynthesis in plants.


Chlorophyll
Chlorophyll is that the pigment that's to blame for the synthesis of food in green plants.
This pigment green colour to its bearers and is abundantly found in leaves.
Chlorophyll is locked inside the chloroplast.
Process of Photosynthesis
The process of photosynthesis takes place within the leaves, the “food factory” of the plants.

Carbon dioxide is taken in through tiny pores on the leaves called stomata.
Water and minerals that are required for the method are transported to the leaves from the roots through the stem.
Chlorophyll helps the leaves use the energy from the daylight to arrange food using the greenhouse emission, water and minerals.
Oxygen is released as a byproduct of this process.
The equation will be given as:


Nutrients Being Replenished in Soil
Nutrients
Plants absorb mineral nutrients from the soil so as to form their own food and for other important processes.
Soils must be enriched with nutrients like nitrogen, phosphorus, potassium etc regularly.
Only then can we grow plants and keep them healthy.
There are 17 most significant nutrients for plants.
6 are called macronutrients and rest are called micronutrients.
Macronutrients are required in large quantities while micronutrients are required in very small quantities.
Other Modes of Nutrition
Symbiotic Relationship
Organisms that live together and share their shelter and nutrients are said to be during a symbiotic relationship.

Certain fungi sleep in the roots of trees.
The tree provides nutrients to the fungus and, in return, receives help from it to require up water and nutrients from the soil.
This association works well for both the fungi and also the tree.
Another commonest example is of Rhizobium bacteria.
They reside within the root nodules of leguminous plants.
The bacteria provide a plant with nitrogen that they fix and successively, they get shelter and food from the plant.
Rhizobium
Rhizobium may be a form of bacteria that convert atmospheric nitrogen into a soluble form that may be utilised by plants (nitrogen fixation).
It usually resides within the roots of leguminous plants like peas, gram, moong etc and is instrumental in providing these plants with a chic source of nitrogen.
Nitrogen Fixation
Nitrogen is a very important nutrient required for soil and for plants.
However, nitrogen within the atmosphere isn't easily accessible.
The process by which nitrogen is converted into a form that may be utilized by plants and other living organisms is termed organic process.

Parasites
A parasite may be a heterotroph that completely depends on another organism for its food.

The organism to which the parasite latches onto is termed the host.
The host, within the process, is bereft of all nutrients for its own growth as they're consumed by the parasite.
For example, Cuscuta (Amarbel) may be a nongreen plant that takes readymade food from the plant on which it's growing.
Saprotrophs
Organisms which depend upon dead and decaying matter for his or her food are called Saprotrophs.

This mode of nutrition is termed saprotrophic nutrition.
For example, Fungi.
Fungi secrete digestive juices on the dead and decaying matter and convert it into an answer.
Then they absorb the nutrients from it.
Insectivorous Plants
Plants that kill insects are called Insectivorous plants.

These plants are green and perform photosynthesis.
But they grow in nitrogen-deficient soils.
So, so as to induce nitrogen, they kill insects.
These insectivorous plants have their parts modified for attracting and catching insects.
For example, The carnivorous plant, Venous flytrap


Did You Know?
Cactus Plants
Most of the photosynthesis takes place within the leaves of green plants.
However, just in case of some desert plants, it takes place in their stem and even branches.
Cacti are found within the desert and their leaves are modified to spines to avoid loss of water because of transpiration.
Therefore, their green stems enable them to hold out the method of photosynthesis