Why is it diagram 4 because I need to explain my answer to?

Six amino acids have side chains that are polar but not charged. these are serine (ser), threonine (thr), cysteine (cys), asparagine (asn), glutamine (gln), and tyrosine (tyr). these amino acids are usually found at the surface of proteins, as discussed in the proteins 2 module.

Interacting group of various species in a common location. for example, a forest of trees and undergrowth plants, inhabited by animals and rooted in soil containing bacteria and fungi, constitutes a biological community.

Droughts cause very arid places such as a desert