Answer:
Because natural selection selects for it. Thus it persists.
Explanation:
You have to understand heterozygote advantage. Basically, it's where heterozygotes have an advantage over homozygotes. In the case of sickle cell disease, heterozygotes have an advantage, and natural selection favors whatever is advantageous. Thus, because heterozygotes each have one recessive sickle-cell allele, as natural selection favors the heterozygotes, the recessive sickle-cell allele persists and remains in the gene pool.
Our fingerprints are like our own dna that makes up our identity. Our fingerprints are like a serial code which can be scanned like the iPhone.
Release of a neurotransmitter across the synapse is triggered by the entry of Ca++ into the presynaptic axon. No Ca++ entry means no transmission across the synapse.
Answer:
Melting ice and rising seas
When water warms up it expands. At the same time global warming causes polar ice sheets and glaciers to melt. The combination of these changes is causing sea levels to rise, resulting in flooding and erosion of coastal and low lying areas
Answer:
If the Earth suddenly had no gravity, the Earth’s atmosphere would float into space. Everything not attached to the Earth would fly off into space. Things like trees and most buildings would remain because they are rooted. Since the Earth, itself, is held together by gravity, it would most probably break apart into chunks and float off.
Explanation:
