ScienceClass 7Full Content

Nutrition in Plants

How plants make their own food through photosynthesis and other modes of nutrition.

Key Topics

Autotrophic Nutrition

Plants make their own food using sunlight, CO₂ from air, and water from soil. This process is called PHOTOSYNTHESIS. Chlorophyll (green pigment in leaves) traps solar energy. Occurs in chloroplasts. Plants are called autotrophs (self-feeders).

Photosynthesis Process

Open topic

Equation: 6CO₂ + 6H₂O + Sunlight → C₆H₁₂O₆ + 6O₂. Light absorbed by chlorophyll. Water absorbed by roots, moves up through xylem. CO₂ enters through stomata (tiny pores in leaves). Glucose is the food; oxygen is released as byproduct.

Other Modes of Nutrition

Open topic

Parasitic: Cuscuta (Amarbel) grows on other plants, takes nutrition from host. Insectivorous: Venus Flytrap, Pitcher Plant — trap and digest insects for nitrogen. Saprophytic: Fungi, mushrooms — feed on dead/decaying matter. Symbiotic: Lichens — alga + fungi live together.

Formulas

Photosynthesis Equation

Formula detail

6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂

Every day green plants around us do this using sunlight

Experiments

Testing a Leaf for Starch (Iodine Test)

Objective: Show that leaves exposed to light produce starch (food) through photosynthesis

Materials: Potted plant, Alcohol, Iodine solution, Beaker, Water bath, Forceps

Result: Exposed part turns BLUE-BLACK (starch present). Covered part stays BROWN (no starch). Proves photosynthesis requires light!

Safety: Alcohol is flammable — never heat directly on flame. Use water bath. Use forceps to handle hot leaf.

Video Links

▶️ Videos open on YouTube and belong to their respective creators. MscTutor does not host or own this content.

Nutrition in Plants - Photosynthesis Class 7

Source: YouTube ↗

16 min

Starch Test Experiment in Plants

Source: YouTube ↗

10 min

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