There’s no picture how do I know which one?
Multicellular organisms require a lot of energy and resources to survive.
Unicellular organisms, on the other hand, require just the basic necessities. On top of that, unicellular organisms don't require a long time to reproduce as multicellular organisms do.
Thus, multicellular organisms are at a disadvantage because they require more energy, sources, and essentially time.
Hope this helps!
Answer:
The monomers of DNA are composed of nucleotide.
I’m not 100% sure if this is a scientific theory but I’m going with the big bang theory. The big bang theory is a scientist best guess on how the world came to be. A 2013 map of the background radiation left over from the Big Bang, taken by the ESA's Planck spacecraft, captured the oldest light in the universe. This information helps astronomers determine the age of the universe.