No, the sickle-cell anemia allele won't be eliminated by natural selection.
Sickle-cell anemia trait is controlled by a single gene and the allele (S) for sickle-cell anemia is a harmful autosomal recessive.
It is caused by a mutation in the normal allele (A) for hemoglobin (a protein on red blood cells).
Heterozygotes (AS) with the sickle-cell allele are resistant to malaria, a deadly tropical disease. It is common in many African populations.
In these areas, (S) carriers have been naturally selected, because their red blood cells, containing some abnormal hemoglobin, tend to be in sickle shape when they are infected by the malarial parasite.
Therefore, they are more likely to survive and reproduce. This keeps the S allele in the gene pool.
Learn more about Sickle-cell anemia on
brainly.com/question/14505007
#SPJ4
Sustain Life and Growth
Air consists one of the main life-sustaining gas called oxygen. Almost all living things breathe in and breathe out this air. Nitrogen and Carbon dioxide are also other gases that are vital for plants and their growth.
Combustion
Apart from this, air supports burning or combustion. The oxygen present in air help in burning of the fuels to basically carry out activities like cooking food, running industries and vehicles as well as generating heat and electricity.
Temperature Control
Another important aspect of air is that it helps in maintaining the temperature on the earth surface by circulating hot and cold air. Air acts as a conductor of heat as well. Even phenomena such as water cycle are dependent on air.
Supplier of Energy
Air which consists of energy is one of the main suppliers of energy. Living things are made up of cells and these cells extract oxygen within the blood to produce energy usually in the form of ATP. This biochemical generation of ATP is essential to maintain life on the earth.
Photosynthesis
Carbon dioxide, which is a component of air is used by plants during the process of photosynthesis. Here oxygen is also released by plants. And we already know how vital oxygen is.
Answer:
(B). The drug is reabsorbed.
Explanation:
Renal clearance rate determines the excretion of drugs into the urine during excretion. It is used to study the main process associated with a drug's renal excretion.
When the renal clearance rate is lower than GFR (glomerulus filtration rate), the drug is absorbed in the renal tubules. When the renal clearance rate is higher than GFR, the drug is secreted into the urine. When the renal clearance rate is equal to the GFR, the drug is neither reabsorbed nor secreted.
As for given drug, renal clearance is 20 ml/min (less than GFR), this drug will reabsorbed.
Thus, the correct answer is option (B).
I just did it and got it correct the answer is inside the circle which is the first one. Good luck on the questions.
Is that they all have the same routine