The most abundant element is oxygen...found in the crust and in the atmosphere.
The correct answer is: D. all of the above
A macromolecule is a large molecule present in the cell, composed of a huge number of monomer units with the various functions. There are four main groups: proteins (monomers are amino acids), nucleic acids (monomers are nucleotids) , lipids (monomers are free fatty acids) and carbohydrates (monomers are simple sugars such as glucose).
Some of their functions:
• Provide structure on the cellular levels-lipids (phospholipids) are the main components of the cell membrane;
• store genetic material-nucleic acid (DNA, RNA) are the carriers of genetic information
• store energy-starch is energy source in plants;
• enzymes -proteins often are with the functionin metabolism
• etc.
Answer:
the scrotum provides a slightly cooler temperature for optimal sperm production
Explanation:
I believe that the loop of Henle is the hairpin structure that connects the proximal and distal convoluted tubules. The loop of Henle is composed of the ascending and the descending limb. The descending loop of Henle connects the proximal convoluted tube with the ascending limb of the loop of Henle, while the ascending loop of Henle connects the descending limb of the loop of Henle with the distal convoluted tubule.