CBSE Class 7 Science Chapter 1 - Nutrition in Plants Revision Notes

Nutrition in Plants

• Photosynthesis is the process by which green plants prepare their own food using chlorophyll, carbon dioxide, water, and sunlight.
• Chlorophyll is essential for photosynthesis to occur, and it helps store solar energy in the form of food in the leaves.
• During photosynthesis, plants produce complex chemical compounds such as sugars and oxygen.
• Oxygen is created during photosynthesis, which is essential for the survival of living species.

Types of Nutrition

• Autotrophic organisms, such as green plants, produce their own food through photosynthesis.
• Heterotrophic organisms, including plants and animals, rely on others for their nutrition.
• Saprotrophs, such as fungi, obtain their food from dead and decaying plant and animal matter.
• Parasitic plants, such as Cuscuta, obtain their food by feeding on another plant (host).
• Total parasites, like mistletoe, rely entirely on the host for nourishment, whereas partial parasites, like the painted cup, obtain some of their nutrients from the host.

Symbiotic Nutrition

• Symbiosis is a type of nutrition in which two or more individuals collaborate to meet their nutritional needs.
• An example of symbiosis is the relationship between algae and fungus, which forms lichens on tree trunks, where the fungus provides water to algae, and algae provide food to fungus.

Insectivorous Plants

• Insectivorous plants, such as pitcher plants, bladderworts, and Venus flytraps, obtain their nutrition from both the soil and small insects.