I believe the answer is Genes??If that is the answer. Hope this helps
The high surface tension of water, so as many other of its properties, is due to the strong attraction force created by the hydrogen bonding, which is the attraction between neighbors hydrogen atoms (with a partial positive charge) and oxygen atoms (with partial negative charge)
Answer is its hydrogen bonding.
Answer: when conditions for survival are unfavorable
Since there is two organism involved, sexual reproduction also increase the genetic variability of the population. This makes the population could adapt in wide condition. When the condition of the habitat changes and make survival is harder for general population, there might be someone with genetic variability that become favored instead.
Air because of the density
All genetic information is found in the DNA
