Very Short Question and Answers - Nutrition - Part 1

The primary source of energy and materials for living organisms is the food they eat.

Autotrophs are organisms that produce their own food from inorganic substances. Examples include green plants and some bacteria.

Heterotrophs acquire their food by consuming complex substances that have to be broken down into simpler ones.

Photosynthesis is the process by which autotrophs convert light energy into chemical energy, using carbon dioxide and water to produce carbohydrates.

Chlorophyll absorbs light energy, which is essential for the process of photosynthesis.

The three main events are: absorption of light energy by chlorophyll, conversion of light energy to chemical energy and splitting of water molecules, and reduction of carbon dioxide to carbohydrates.

Starch serves as an internal energy reserve in plants, which can be utilized when required.

Stomata are tiny pores on the surface of leaves that facilitate gaseous exchange during photosynthesis.

Guard cells swell with water to open the stomatal pore and shrink to close it.

Potassium hydroxide is used to absorb carbon dioxide to determine its effect on starch production in plants.

If a leaf shows the presence of starch, it indicates that photosynthesis occurred in that leaf.

Plants absorb water from the soil through their roots.

Plants need essential elements such as nitrogen, phosphorus, iron, and magnesium.

The parts of the leaf that contain starch turn blue-black when iodine solution is applied.

Immersing the leaf in boiling water helps kill the leaf and breaks down cell structures, making it easier to test for starch.

Plants close their stomata to prevent excessive water loss during periods when carbon dioxide for photosynthesis is not needed.

The survival of heterotrophs depends directly or indirectly on autotrophs, as heterotrophs consume autotrophs for energy.

Carbon dioxide is converted into carbohydrates that provide energy to the plant.

We can design an experiment where one plant is kept in the dark and another in sunlight, then compare starch production.

Nitrogen is essential for the synthesis of proteins and other compounds in plants.