Nutrition in plants Chapter 1 Science Class 7th Notes CBSE

Introduction to Nutrition in Plants

Carbohydrates,proteins, fats, vitamins and minerals are components of food. These components of food are called nutrients and are necessary for our body.

All living organisms require food. Plants can synthesise food for themselves but animals including

humans cannot. They get it from plants or animals that eat plants. Thus, humans and animals are directly or indirectly dependent on plants

Nutrition

Nutrition is the mode of taking food by an organism and its utilisation by the body.

Nutrition is very important because of build their bodies and grow of living organisms and help to repair damaged parts of organs. its also provides energy for doing various function

Autotrophs

The mode of nutrition in which organisms make food themselves from simple substances is called autotrophic (auto = self; trophos= nourishment) nutrition. Therefore, plants are called autotrophs.

plants make their own food using carbon dioxide, water and light energy

Heterotrophs

Animals and most other organisms take in food prepared by plants. They are called heterotrophs (heteros = other).

Photosynthesis

Photosynthesis is a process making food by green plants

It helps leaves to capture the energy of the sunlight. This energy is used to synthesise (prepare) food from carbon dioxide and water. Since the synthesis of food occurs in the presence of sunlight, it is called photosynthesis (Photo: light; synthesis :to combine).

Stomata

Carbon dioxide from air is taken in through the tiny pores present on the surface of leaves. These pores are surrounded by ‘guard cells’. Such pores are called stomata

Vessels

Water and minerals are transported to the leaves by the vessels which run like pipes throughout the root, the stem, the branches and the leaves. They form a continuous path or passage for the nutrients to reach the leaf. They are called vessels

Chlorophyll

Its helps leaves to capture the energy of the sunlight. The leaves have a green pigment called chlorophyll . it is locked inside the chloroplast.

Chloroplasts

The chloroplast is a cell organelle of the plant cell. An organelle is a distinct part of a cell which has a particular structure and function.

Process of Photosynthesis

The process of photosynthesis takes place at the leaves and also says “food factory” of the plants.

Water and minerals that are required for the process are transported to the leaves from the roots through the stem.
Carbon dioxide is taken in through tiny pores on the leaves called stomata.
Chlorophyll helps the leaves use the energy from the sunlight to prepare food using the carbon dioxide, water and minerals.
Oxygen is released as a by product of this process.

The process can be represented in an equation

Carbon dioxide + water → [sunlight/ Chlorophyll] carbohydrate + oxygen

Cells

A cell is the basic unit of life, and it is the smallest structure that can perform all the functions necessary for life. It is the building block of all living organisms, from simple single-celled organisms like bacteria to complex multi-cellular organisms like humans.

A cell is composed of several components, including a cell membrane, cytoplasm, and genetic material (DNA).
The cell membrane is a thin, flexible layer that encloses the cell and regulates the movement of materials in and out of the cell.
The cytoplasm is a gel-like substance that fills the cell and contains organelles, small structures that perform specific functions within the cell.
The genetic material of a cell is contained within the nucleus, which is a specialized organelle that controls the cell's activities and contains the DNA that carries the instructions for all of the cell's functions.

There are two main types of cells: prokaryotic cells, which are simpler in structure and do not have a nucleus, and eukaryotic cells, which are more complex and have a nucle

OTHER MODES OF NUTRITION IN PLANTS

Symbiotic Relationship

Plant and organism that live together and share their shelter and nutrients are said to be in a symbiotic relationship.

Example of a symbiotic relationship in plant nutrition is the association between certain plants and nitrogen-fixing bacteria, such as those in the genus Rhizobium. These bacteria live in nodules on the roots of legumes (such as beans, peas, and clovers) and convert atmospheric nitrogen into a form that the plant can use. In exchange, the plant provides the bacteria with carbohydrates.

Rhizobium

Rhizobium is a genus of bacteria that can form a mutualistic relationship with legume plants.

They live in nodules on the roots of the plant and fix atmospheric nitrogen into a usable form for the plant.
This process is important for the growth and development of the plant, and legume crops can be used as a natural source of nitrogen fertilizer, reducing the need for synthetic fertilizers.

Parasites

Parasites are organisms that live on or inside a host organism and rely on the host for survival.

They can cause harm to the host by consuming its nutrients, tissues, or fluids.
Examples of parasites include tapeworms, fleas, and malaria parasites.
Parasitic infections can be prevented through proper hygiene, vaccination, and medication,

but they can also have significant impacts on human and animal health, as well as on agricultural productivity.

Saprotrophs

Saprotrophs are organisms that obtain their nutrition by breaking down and absorbing dead and decaying organic matter, such as dead plant and animal material.

Examples of saprotrophs include fungi and bacteria.

They play an important role in the decomposition and recycling of organic matter in ecosystems, making nutrients available for use by other organisms.
Some saprotrophs can also cause disease in plants and animals, but many are beneficial for the health of ecosystems

Insectivorous Plants

Insect-eating plants are called insectivorous plants

Such plants may be green or of some other colour.
The pitcher-like or jug-like structure is the modified part of leaf.
The apex of the leaf forms a lid which can open and close the mouth of the pitcher.
Inside the pitcher there are hair which are directed downwards. When an insect lands in the pitcher, the lid closes and the trapped insect gets entangled into the hair.
The lid closes and the insect is trapped.
The insect is digested by the digestive juices secreted in the pitcher and its nutrients are absorbed. Such insect-eating plants are called insectivorous plants

Nutrients Being Replenished in Soil

Nutrients

Plants need nutrients to grow and absorb them from the soil, which can become depleted over time. Fertilizers and manure can help replenish the soil. Most crops require nitrogen, which is often deficient in the soil. Rhizobium is a bacterium that can convert atmospheric nitrogen into a usable form for plants, and it often lives in the roots of legumes. In return, the plants provide food and shelter to the bacteria, creating a symbiotic relationship. Parasitic and saprotrophic plants derive nutrition from other organisms, while most plants are autotrophs. Insectivorous plants may be considered partial heterotrophs.

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Nutrition in plants Chapter 1 Science Class 7th Notes CBSE