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Definition of Cell
It is known as the smallest basic structural and fundamental unit of life because it is the building block of an organism. All living organisms are made up of cells, and cells perform all the essential activities needed for life. cells make up every plant, animal, and microorganism.
History of Cell Discovery
The process of acquiring oxygen from outside the body and using it in the process of breakdown of food sources for cellular needs, is called respiration.
Excretion
The removal of metabolic waste products that could be toxic if accumulated. These waste products are carbon dioxide (exhaled), nitrogenous wastes (urea, uric acid), excess salts, and water; these are eliminated via lungs, kidneys, skin, or in plants through stomata.
Nutrition
The process by which organisms take in food (carbon‑based molecules) from their environment and break it down into simpler substances. These nutrients needed for maintenance, repair, growth, and chemical activity in every cell.
Mode of Nutrition
- Autotrophic
- Heterotrophic
Autotrophic nutrition is a mode of nutrition in which organisms prepare their own food using simple substances like carbon dioxide and water in the presence of sunlight. This process is mostly seen in green plants and some bacterias.
Heterotrophic nutrition is a mode of nutrition in which organisms cannot make their own food and depend on other plants or animals for their nutrition. They consume organic matter for energy and growth.
Transportation
The movement of dissolved substances, nutrients, gases (O₂/CO₂), hormones, and wastes throughout the body. In animals, this takes place via the circulatory system (blood, heart, vessels); in plants, via xylem (water/minerals) and phloem (sugars).