Important words meanings in Hindi from Class 12th Biology Chapter 4:

1. Photosynthesis (प्रकाश संश्लेषण):
Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. It is a crucial process for the survival of plants and ultimately for all living organisms.

2. Chlorophyll (क्लोरोफिल):
Chlorophyll is a green pigment found in the chloroplasts of plant cells. It plays a vital role in photosynthesis by capturing light energy and converting it into chemical energy that the plant can use to synthesize food.

3. Stomata (स्टोमेटा):
Stomata are small pores present on the surface of leaves that regulate the exchange of gases like oxygen and carbon dioxide during photosynthesis. They also help in the transpiration process by allowing water vapor to escape.

4. Transpiration (वाष्पोत्सर्जन):
Transpiration is the process by which plants lose water in the form of water vapor through stomata on their leaves. It helps in the absorption of water and minerals from the soil and also helps in cooling the plant.

5. Calvin cycle (कैल्विन चक्र):
The Calvin cycle is a series of chemical reactions that take place in the stroma of chloroplasts during photosynthesis. It involves the conversion of carbon dioxide into glucose with the help of ATP and NADPH produced during the light-dependent reactions.
Understanding these important terms in Hindi will help students grasp the concepts of photosynthesis and plant physiology more effectively.