Question

Many cacti in the desert have thick, photosynthetic stems and few or no leaves (or leaves that are modified as spines). why is this body shape adaptive?

Answer 1

Deserts has a very dry and hot climate, this may increase the water loss of plants through the leaves. Therefore, to prevent large amount of water loss in cactus, their leaves are modified to spines to reduce the surface area. In addition, the thick photosynthetic stems can help absorb and store more water, which is the necessary element for living things.