Answer the following question given this paragraph: 

30.4 | Leaves By the end of this section, you will be able to: • Identify the parts of a typical leaf • Describe the internal structure and function of a leaf • Compare and contrast simple leaves and compound leaves • List and describe examples of modified leaves Leaves are the main sites for photosynthesis: the process by which plants synthesize food. Most leaves are usually green, due to the presence of chlorophyll in the leaf cells. However, some leaves may have different colors, caused by other plant pigments that mask the green chlorophyll. The thickness, shape, and size of leaves are adapted to the environment. Each variation helps a plant species maximize its chances of survival in a particular habitat. Usually, the leaves of plants growing in tropical rainforests have larger surface areas than those of plants growing in deserts or very cold conditions, which are likely to have a smaller surface area to minimize water loss.


Q: The presence of what in leaf cells makes most leaves appear green?


A:
chlorophyll