1. Location:
- Stomata are tiny pores found on the surface of plant leaves, stems, and other organs.
- Gills are structures found on the body of aquatic animals, such as fish and some amphibians, typically located on the sides of the head or along the body.
2. Function:
- Stomata are responsible for the exchange of gases between plants and the atmosphere. They allow carbon dioxide (CO2) to enter the plant for photosynthesis, and oxygen (O2) to be released.
- Gills facilitate the exchange of gases between aquatic animals and the water. They absorb dissolved oxygen from the water and release carbon dioxide.
3. Structure:
- Stomata consist of two bean-shaped cells called guard cells that surround a pore called the stomatal pore. The guard cells can open or close to regulate the size of the pore and control the exchange of gases.
- Gills are composed of thin filaments or lamellae that provide a large surface area for gas exchange. These filaments are highly vascularized, allowing for the efficient exchange of gases between the blood of the animal and the surrounding water.
4. Mechanism of Gas Exchange:
- Stomata open to allow CO2 to diffuse into the leaf for photosynthesis during the day. They close at night to prevent water loss and conserve heat.
- Gills are constantly bathed in water, and the exchange of gases occurs through diffusion across the thin gill filaments. The water passing over the gills creates a flow that facilitates continuous gas exchange.
5. Respiratory Medium:
- Stomata are adapted for gas exchange with air, which has a lower density and concentration of CO2 compared to water.
- Gills are specialized for extracting oxygen from water, which has a higher density and lower concentration of oxygen compared to air.
In summary, stomata are structures on plants that regulate gas exchange with the atmosphere, primarily for photosynthesis and respiration. Gills, on the other hand, are respiratory organs found in aquatic animals, enabling the efficient exchange of gases between the animal's blood and the surrounding water.