Nutrition in Plants — Important Questions

Leaf

Step 1: For photosynthesis to happen, a plant needs chlorophyll, sunlight, water, and carbon dioxide. Step 2: Leaves contain the most chlorophyll and have a flat, broad shape to capture maximum sunlight. Step 3: Leaves also have stomata for gas exchange and veins that supply water and minerals. Step 4: This is why leaves are called the 'food factories' of plants. Roots absorb water, stems provide support and transport, and flowers help in reproduction.

Carbohydrate (Starch)

Step 1: When plants perform photosynthesis, they combine carbon dioxide and water using sunlight energy. Step 2: This produces carbohydrates, specifically in the form of sugars, which are then stored as starch. Step 3: We can test for the presence of starch in leaves using iodine solution – it turns blue-black if starch is present. Step 4: Proteins, fats, and vitamins are other nutrients but are NOT the direct products of photosynthesis.

Parasitic nutrition

Step 1: Cuscuta (Amarbel) is a yellow, wiry plant that twines around other plants. Step 2: It does not have chlorophyll, so it cannot make its own food. Step 3: It takes readymade food from the plant it grows on (called the host), harming the host plant. Step 4: Since Cuscuta depends on and harms another organism (host) for food, it is called a parasite and shows parasitic nutrition. Autotrophic means making own food, saprotrophic means feeding on dead matter, and symbiosis is a mutually beneficial relationship.

Mushroom

Step 1: Saprotrophic nutrition means getting nutrients from dead and decaying organic matter. Step 2: Mushrooms are fungi that do not have chlorophyll, so they cannot make their own food. Step 3: They release digestive juices on dead or decaying material, break it down, and absorb the nutrients. Step 4: This is why mushrooms grow on rotting wood, moist soil, or decaying food. Cuscuta is a parasite, pitcher plant traps insects, and mango tree is an autotroph.