Answer:
The correct answer is Each nucleotide is connected to three nitrogenous bases.
- Deoxyribonucleic acid (DNA) is a genetic material composed of nucleotides.
- Each nucleotide is made up of three elements: a phosphate group, a sugar group (deoxy ribose), and a nitrogenous base.
- There are four types of nitrogenous bases found in the DNA : adenine (A), guanine (G), thymine (T), and cytosine (C).
- Phosphate binds to a sugar group with the help of ester bond and sugar binds to a nitrogenous base with the help of glycosidic bond.
- Nucleotides bind with each other with the help of phospodiester bond to form the polynucleotide chain.
- The two nucleotide chains are held together with the help of hydrogen bonding between nitrogenous bases of two strands. They form the double helical structure of the DNA.
- The two strands lei in anti-parallel orientation.
- It is also important to note that adenine always binds with thymine with the help of two hydrogen bonds and guanine always binds with cytosine with the help of three hydrogen bonds.
The correct answer is a lymph vessel that transports lymph to the lymph node.
The lymphatic system is the component of the vascular system and an essential immune system part, consisting of a network of lymphatic vessels, which transports a clear fluid known as lymph directionally towards the heart. Like the circulatory system, the lymphatic system is not a closed system.
One of the prime activities of the lymphatic system is to offer an addition return passage to the blood for the remaining three liters. The other main activity is that of defense in the immune system.