The word that best fits the underlined in the sentence is "free-to-rotate." The carbon atoms in their carbon bonds are free to rotate since alkanes do not have geometric isomers. They only have single bonds and the most common example of which are trans molecules.
<span>This example represents the challenge of survival of the fittest. In this situation, the trees have a distinct advantage due to their above average height. This puts them in the best position to gain the resources that they need to survive, most notably, the sun. The smaller plants, however, do not have this advantage, and lose out to the trees.</span>
