Answer: Option A.
nephron loop multiplies the concentration of salts in the interstitial fluid of the kidney medulla.
Explanation:
countercurrent multiplier is a system that utilize energy that create osmotic gradients and enable reabsorption of water thereby increase concentration of urine. The countercurrent multiplier uses electrolyte pumps there by making the nephron loop increase the concentration of salts in the interstitial fluid of the kidney medulla because it allows the nephron to reabsorb alot of water and and increase the concentration of urine for excretion while at the same time using as little energy as possible.
Chromosomes are composed of deoxyribonucleic acid (DNA) mole
There are mainly two molecules that function as genetic material in living organisms.
These are ribonucleic acid(RNA) and deoxyribonucleic acid(DNA).
The organisms having DNA as genetic material require packaging of DNA as it is a long polymer of deoxyribonucleotides.
In the case of human beings, the length of DNA in a cell is approximately 2.2 meters which is very large as compared to the size of the nucleus( approximately 10^-6 meters).
So, the DNA has to be made compact for it to be present inside the nucleus of a cell.
Therefore, the DNA present inside the nucleus of a cell undergoes coiling and compaction through several stages before finally becoming a chromosome, which is shown in the adjoining diagram.
Thus, chromosomes are composed of deoxyribonucleic acid (DNA) molecules.
To know more about "DNA Packaging", refer to the following link:
brainly.com/question/14702559?referrer=searchResults
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