Chapter Notes - Chapter 1: Nutrition in Plants, Class 7, Science

Introduction:
Nutrition is the process by which organisms obtain and utilize food for their growth, development, and maintenance of life processes. In this chapter, we will explore the various modes of nutrition in plants.

Autotrophic Nutrition:
Plants are autotrophs, meaning they can synthesize their own food. They do this through the process of photosynthesis, which takes place in the chloroplasts of their cells. During photosynthesis, plants use sunlight, carbon dioxide, and water to produce glucose (a form of sugar) and oxygen. This glucose is then converted into other complex substances like starch, fats, and proteins.

Heterotrophic Nutrition:
While plants are primarily autotrophs, some plants also exhibit heterotrophic nutrition. This means they obtain nutrients from external sources. For example, insectivorous plants like Venus flytrap and pitcher plants capture and digest insects to obtain additional nutrients.

Parasitic Nutrition:
Parasitic plants obtain their nutrition by living on or inside other plants. They form specialized structures called haustoria, which penetrate the host plant to absorb nutrients directly. Examples of parasitic plants include cuscuta (dodder) and mistletoe.

Saprophytic Nutrition:
Saprophytic plants obtain their nutrition from dead and decaying organic matter. They secrete enzymes that break down organic matter into simpler substances, which are then absorbed by the plant. Fungi such as mushrooms and molds exhibit saprophytic nutrition.

Summary:
In summary, plants exhibit various modes of nutrition including autotrophic, heterotrophic, parasitic, and saprophytic nutrition. Autotrophic nutrition is the primary mode of nutrition in plants, where they synthesize their own food through photosynthesis. However, some plants also exhibit heterotrophic nutrition by obtaining nutrients from external sources. Parasitic plants live on or inside other plants to derive nutrition, while saprophytic plants obtain nutrients from dead organic matter.

By understanding the different modes of nutrition in plants, we can appreciate the diverse strategies employed by plants to acquire the essential nutrients they need for survival and growth.

(Note: The answer provided is a general explanation of the chapter. For a more comprehensive understanding, please refer to the textbook or educational resources like EduRev.)

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