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.
To relieve airway obstruction in infants, lay the baby face down along your forearm using your laps for support. Apply five quick, forceful blows at the baby's back with the palm of your hand.
If the object did not come out, turn the baby face up and give five quick down thrusts. Continue the back slaps and the chest thrust cycle until the baby recovers.
I think the right answer is b
The best answer in terms of how organ cultures are an improvement on this transport method is "<span>Cultured organs can be kept alive for several weeks before transplant."</span>
The organism that was most likely to live at the same time as brachiopods were
Trilobites
Brachiopods were like lamshells. They lived underwater, had soft bodies and their shells were bivalves.
Trilobites had three-lobed bodies. They could swim, crawl, and burrow.
