Mutualism is a symbiotic relationship in which both species benefit. Commensalism is a symbiotic relationship in which one species benefits while the other is not affected. Parasitism is a symbiotic relationship in which the parasitic species benefits while the host species is harmed.
A comparison of the three different forms of double-stranded DNA reveals that <u>Z-DNA</u> has the largest pitch per turn of the helix, whereas <u>A-DNA</u> has the widest diameter.