<span>A biotic factor is a living thing in an ecosystem. The biotic factors can be separated into three different groups; producers, consumers, and decomposers. Examples of biotic factors are animals, plants, trees, bacteria, and molds.</span>
Answer: the <span>Permian–Triassic extinction event ; {"end of the Permian era"} .
_____________________________________________________</span>
The two DNA strands are held together by hydrogen bonding between the bases on the different strands; therefore, all the bases are on the <u>inside of the double helix</u>, and the sugar-phosphate backbones are on the <u>outside.</u>
<u></u>
The two strands are held collectively via hydrogen bonds between pairs of bases: adenine pairs with thymine, and cytosine pairs with guanine.
Covalent bonds arise inside every linear strand and strongly bond the bases, sugars, and phosphate groups (each within each thing and between additives).
Hydrogen bonds occur among the two strands and contain a base from one strand with a base from the second in complementary pairing.
Learn more about Hydrogen bonds here: brainly.com/question/1420470
#SPJ4
<u></u>
<u></u>
The one that is not a piece of molecular evidence supporting the endosymbiotic theory is B) The mitochondria and chloroplasts are much different in structure in bacteria.
Hope this helps! :)
Because their is no gravity in space
