The core practical involves the measurement of oxygen bubbles in the water. Through which part of the plant is oxygen released?

Oxygen is released through the part of the plant called the stomata. These are small openings primarily found on the underside of plant leaves. Here's a step-by-step explanation:

1. Photosynthesis: This is the process by which green plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy in the form of glucose. Oxygen is a by-product of this process.

2. Role of stomata: The stomata are responsible for gas exchange in plants. They allow carbon dioxide (CO2), which is needed for photosynthesis, to enter the plant. At the same time, they allow oxygen (O2), a by-product of photosynthesis, to leave the plant.

3. Oxygen release: During photosynthesis, when light energy is converted into chemical energy, oxygen is produced. This oxygen is then released into the atmosphere through the stomata.

4. Measuring oxygen bubbles: In the core practical you mentioned, you're likely measuring the rate of photosynthesis by counting the number of oxygen bubbles produced. This gives an indication of how much oxygen is being released, and thus, how quickly photosynthesis is occurring.