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.
Answer: chloride ions
Explanation:
This movements of chloride ions into the blood plasma to replace the outward diffused bicarbonate ions is called chloride shift, It occurs to restore the blood ionic balance altered by the bicarbonate ions diffusion out into plasma
The same amounts of Chloride ions replaced the lost amount of bicarbonate ions
The correct answer is option I) Steroid hormones are lipid soluble and easily cross the phospholipid bilayer.
The steroid hormones are made up of steroid molecules, the steroid molecules are hydrophobic and lipid soluble. This property makes help the steroid molecule to cross the phospholipid bilayer membrane easily. The steroid molecule has a direct influence on the genome transcription, they act by binding with the DNA as a transcriptional factor.
Answer:
a. Stabilizing selection
Explanation:
Babies lower than 5.5lbs would suffer from various disorder because of low birth weight as their body would not be able to compete as well they would have weak immune system and malnourishment. Whereas high birth weight carry the equally above risk as their body wont be able to cope up and organs become insensitive to various hormones. for the survival the birth weight should be within a median range so that it would be favorable for themselves and surroundings.
Stabilizing selection occurs when a population stabilizes on a particular trait value and genetic diversity decreases. As in this example, an average baby weight has to favour against extreme variation for it's better survival.
therefore, this is an example of stabilizing selection.
