Nutrition In Plants – Complete Guide For Class 7 Science Chapter 1

Welcome to iPrep, your Learning Super App. Our learning resources for the chapter, Nutrition on Plants in Science for Class 7th are designed to ensure that you grasp this concept with clarity and perfection. Whether you’re studying for an upcoming exam or strengthening your concepts, our engaging animated videos, practice questions and notes offer you the best of integrated learning with interesting explanations and examples. 

The chapter Nutrition in Plants of class 7 Science is a fundamental topic in understanding how plants grow, develop, and contribute to our environment. This chapter covers the essential nutrients that plants need, how they obtain these nutrients, and various modes of nutrition.

Let’s start with understanding What are nutrients?

Nutrients

In the chapter Nutrition in Plants, there is a significant mention of the concept Of Nutrients. Nutrients are crucial for providing energy, building and maintaining body organs, and supporting various metabolic processes in organisms. For plants, the essential nutrients include:

• Carbohydrates
• Proteins
• Fats
• Vitamins

Essential Plant Nutrients

When it comes to Nutrition in Plants, they require specific nutrients to complete their life cycle. Not all nutrients are essential, but they can still benefit from some non-essential nutrients like Sodium (Na) and Silicon (Si).

Nutrition

Nutrition is the process by which organisms obtain and use nutrients for maintaining life. When it comes to Nutrition in plants, there are two primary types of nutrition:

1. Autotrophic Nutrition
2. Heterotrophic Nutrition

Autotrophic Nutrition

Autotrophic nutrition involves the formation of food by using simple inorganic substances. Organisms that perform autotrophic nutrition are known as autotrophs, with green plants being prime examples. They carry out this process through photosynthesis.

Autotrophs

• Green Plants: These organisms create their food through photosynthesis.

Heterotrophic Nutrition

Heterotrophic nutrition relies on other organisms or dead organic matter for food. Organisms that cannot produce their own food are called heterotrophs. Examples include animals and protozoa like amoeba and paramecium.

 Heterotrophs

• Animals
• Protozoa: e.g., Amoeba, Paramecium

Modes of Nutrition

Different organisms have distinct ways of obtaining and utilizing nutrients:

Cells

According to the chapter Nutrition In Plants, all living organisms are made up of cells. Cells are tiny structures that can only be seen under a microscope.

The cell is a small structure that is surrounded by a thin boundary cell membrane. The nucleus is the most conspicuous organelle found in the center of the cell. It houses the cell’s chromosomes and is the place where almost all the processes for the transfer of genetic information occur. The nucleus is surrounded by cytoplasm which is a gelatinous fluid that fills most cells. A nucleus is kept separate from the cytoplasm by a double membrane layer – nuclear membrane.

Types of Cells

• Unicellular: Single-celled organisms (e.g., Amoeba, Paramecium)
• Multicellular: Organisms with multiple cells (e.g., Plants, Animals)

Photosynthesis

The chapter Nutrition in Plants very significant covers the concept of Photosynthesis. Photosynthesis is the process by which plants make their own food using sunlight, carbon dioxide, and water. Basically it is the process that creates the source of nutrition in plants.

• Carbon dioxide from the air is taken through the tiny pores present on the surface of the leaves.
• These pores are surrounded by guard cells which regulate the exchange of carbon dioxide.
• These pores are called stomata.

Photosynthesis Equation

The image given below clearly showcases the equation of photosynthesis, a crucial part of Nutrition in Plants.

Transportation of Minerals

Another form of Nutrition in plants is called transportation of Minerals. Minerals and water are absorbed by plant roots and transported to the leaves via vessels. These vessels create a continuous pathway for nutrient movement.

Pigments

• Chlorophyll: The green pigment in plants that captures light energy for photosynthesis. Found in chloroplasts.

• Other Pigments: Red, brown, and other pigments can mask chlorophyll but still participate in photosynthesis.

Synthesis of Different Foods

Plants synthesize carbohydrates, fats, and proteins. Nitrogen, essential for protein synthesis, is converted into a soluble form by soil bacteria through nitrogen fixation.

Nitrogen Fixation

Bacteria in the soil convert atmospheric nitrogen into a form that plants can absorb and use.

Different Modes of Nutrition in Plants

• Parasitic Plants: Obtain nutrients from host plants. Example: Cuscuta
• Insectivorous Plants: Capture and digest insects for nutrients. Example: Pitcher Plant
• Saprotrophs: Decompose dead organic matter. Examples: Fungi, Bacteria
• Symbiosis: Mutual benefit between two organisms. Example: Lichens

Parasitic Plants

Heterotrophic Nutrition

• Some plants depend on other plants for their food sources- The organism  Heterotrophs.
• They cannot make their own food because they do not have chlorophyll.
• Ingest and oxidize carbohydrates, fats, and proteins synthesized by autotrophs.

Autotrophic Nutrition

Parasitic Plants

• They lack chlorophyll
• Rely on the host plant for water and all nutrients.
• The parasite gains nutrition and in this process, it harms the host plant. Example: Cuscuta (Amerbel)
•  Cuscuta is a yellow tubular plant twining around the stem and branches of a tree.
• It does not have chlorophyll. It takes ready-made food from the host plant on which it is climbing.

Insectivorous Plants

• Just like many animal species, some plant species are carnivorous—that is, they consume insects and other small animals as a primary source of nutrients and minerals for growth.
• Instead of actually eating insects, carnivorous plants trap them by various means, depending on the kind of plant.
• These grow in nutrient-poor habitats.
• The ability of carnivorous plants to capture and digest insects, is supplemented by their capacity to make energy stores by photosynthesis as other green plants do. Example – Pitcher plant.
• In this plant, the pitcher-like structure is the modified part of the leaf. 
• The apex of the leaf forms a lid that 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 insect is digested by the digestive juices secreted in the pitcher.

Saprotrophs

• An organism that obtains its nutrients from non-living organic matter, usually dead and decaying plant or animal matter, by absorbing soluble organic compounds. Example:  fungi, bacteria.
• They secrete digestive juices on the dead and decaying matter and convert it into a solution. Then they absorb nutrients from it. This is called saprotrophic nutrition.
• Saprotrophs 
• As decomposers, they allow essential materials (e.g. C, N) to be recycled in the ecosystem.

• Fungi also grow on pickles, leather, clothes and other articles that are left in hot and humid weather for a long time.  During the rainy season, they spoil many things.

Symbiotic Relationships

• The intimate association between two distantly, related species that are mutually benefiting from this association.  For example – certain fungi live in the roots of the trees.
• Fungi enhance mineral transport to plants, especially phosphorous.
• The tree provides nutrients to the fungus.
• Plants with fungi are more drought-resistant.
• Plants with fungi are more resistant to plant pathogens.

• Lichens: A partnership between fungi and algae. Fungi provide shelter and minerals, while algae provide food through photosynthesis.
  

Let’s summarize the mode of nutrition in a flow chart:

Replenishment of Nutrients in Soil

To maintain soil fertility, nutrients must be replenished through fertilizers, manures, and biological means like nitrogen fixation.

Rhizobium in Legume Plants

Rhizobium bacteria form a symbiotic relationship with legume plants to convert atmospheric nitrogen into a form usable by plants. In return, the plants provide food and shelter for the bacteria.

This blog provides a comprehensive overview of Nutrition in Plants, helping students grasp fundamental concepts and appreciate the complexity of plant life.

In conclusion, Class 7 Science Chapter 1 – Nutrition in Plants is essential for understanding how plants sustain themselves and contribute to the environment. By exploring the different modes of nutrition such as autotrophic, heterotrophic, and symbiotic relationships, this chapter provides a solid foundation for students to grasp the intricacies of plant biology. The concept of Nutrition in Plants not only highlights the importance of nutrients for plant growth but also underscores the interconnectedness of various life forms in an ecosystem. Through this chapter, students will gain valuable insights into the vital processes that support life on Earth, making Nutrition in Plants a cornerstone of their scientific education.