ii.3. From Single Cells to Specialized Organs, Exploring the Evolution of Nutritional Processes in Organisms
- Organisms employ diverse methods to obtain nutrition, and their digestive systems vary accordingly.
- In single-celled organisms, such as Amoeba, the entire surface may serve for food intake.
- As organisms become more complex, specialized parts emerge to carry out distinct functions.
- For instance, Amoeba utilizes temporary extensions of the cell surface to form a food-vacuole, where complex substances are broken down into simpler ones.
- The nutrients then diffuse into the cytoplasm, while undigested material is expelled from the cell surface.
- In Paramoecium, another unicellular organism, a specific spot on the cell is designated for food intake.
Cilia, covering the cell surface, facilitate the movement of food to this spot, showcasing the adaptability of organisms in their nutritional strategies.