9. A desert ecosystem shows many examples of interactions between biotic and abiotic parts.
a. Describe two biotic and two abiotic parts of the desert ecosystem.
b. Choose one botic and one abiotic part of the desert ecosystem, and explain the
interaction between the two parts.

An ecosystem consist of living organisms and non- living organisms and how they interact among them.

Explanation:

a. Two biotic and two abiotic parts of the desert ecosystem are as follows sand as well as rocks are two abiotic parts and cactus as well as aloe plants are the two biotic parts of the desert ecosystem.

b. In an ecosystem a biotic and an abiotic component interact among each other , if we consider the interaction between a cactus and the sand we can see that as cactus has the ability to survive in a hot temperature the spines takes part in conserving water and the roots of the cactus go deep inside the soil.  

the answer your looking for is c).