The answer is Carbohydrates
He begins by discussing how horizontal transfer can move genetic material between bacteria. Transformation, transduction, and conjugation in bacteria are all included. He also explains how crossing over, random assortment, and random fertilization can maintain genetic variation in eukaryotes.
There are 4 valence electrons
Due to the increasing temperature in ocean it is more advantageous for start fishes to reproduce asexually because they can regenerate via a process called fragmentation.
In fragmentation, a part of arm or a part of disc is separated from the parent body and grows into a complete new organism; an individual star fish.
Moreover, regeneration is the ability of an organism to renew, or re-grow any part of the body, makes it resilient to environmental fluctuations.