Collenchyma and sclerenchyma fibers both have a similar main function. what is it?

To provide mechanical support to the plant parts

Explanation:

Collenchyma fibers consist of living cells with unevenly thickened primary cell walls and mainly serve to provide support to the plant parts of herbs. These fibers provide elastic support and are also present in the form of long strands near the surface of stems and along the leaf veins.  

Sclerenchyma fibers consist of dead cells at maturity and have an extremely thick cell wall. The main function of these fibers is to provide strength and support to the plant body. The presence of thick secondary cell walls in cells of sclerenchymatous fibers makes them strong and hard to provide mechanical support and strength to plant part. These fibers are particularly abundant in stems of woody trees and certain types of leaves.  

when it's short and dry.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.