The bond formed between the sugar of one nucleotide and the phosphate of an adjacent nucleotide is a covalent bond. A covalent bond is the sharing of electrons between atoms. A covalent bond is stronger than a hydrogen bond (hydrogen bonds hold pairs of nucleotides together on opposite strands in DNA). Thus, the covalent bond is crucial to the backbone of the DNA. 

Uracil is bound to adenine in the production of RNA, while thymine is used in its place in the production of DNA. Adenine, guanine, and cytosine are all used in the production of both RNA and DNA.

Cytosine and guanine form three hydrogen bonds between each other, while tyrosine and adenine form two hydrogen bonds. We simply need to count how many of each base we have and multiple cytosine and guanine by three, and thymine and adenine by two.

CGTTTGAC has 2 cytosine, 2 guanine, 3 thymine, and 1 adenine.

DNA and RNA are made of nucleotides, which contain oxygen, hydrogen, nitrogen, carbon, and phosphorus. The nucleic acid backbone is comprised of sugars, made of carbon, hydrogen, and oxygen, and phosphate groups, made of phosphorus, hydrogen, and oxygen. The backbone binds to bases, which contain a nitrogen element.

Potassium is not found in nucleic acid structure, and is used in other parts of the body like muscles and nerves for signal propagation.

This question is mostly about the differentiations between a nucleoside and a nucleotide. A nucleoside is composed of a nitrogenous base and a ribose or deoxyribose sugar. A nitrogenous base, a ribose/deoxyribose sugar, and a phosphate describe a nucleotide. Remember that nucleosides are incomplete nucleotides, and lack a phosphate group.

Cytosine and guanine, when base paired, have three hydrogen bonds between them. Adenine and thymine only have two. This extra hydrogen bond helps make the cytosine-guanine pair favorable because it increases stability, and reduces bond energy.

Ionic and covalent bonds do not occur between nitrogenous bases in DNA. Covalent bonds are found in the DNA backbone (known as phosphodiester bonds).

Due to DNA's double-helical structure, the nucleotide bases are paired. Adenine is paired with thymine and guanine is paired with cytosine. Chargaff found that there is typically an equivalent number of adenine and thymine bases, and an equivalent number of guanine and cytosine bases. In a given sample of DNA, all adenine residues will have thymine counterparts on the complementary strand, and all cytosine residues will have complementary guanine counterparts. As a result, there will be equal numbers of each residue of the base pair in any sample of double-stranded DNA.

When determining complementary strands, there are a few important points to consider. First, remember that uracil is only found in RNA. We can eliminate any answer choices that contain uracil. Second, remember that DNA is anti-parallel. This means that the 3' end of the template strand must match up with the 5' end of the complementary strand. Flip any answers that have both 3' ends together. Finally, make sure that the bases align correctly. Adenine and thymine should always pair and cytosine and guanine should always pair.

Template strand: 3'-ATTGC-5’

Complementary strand is antiparallel: 5'-_ _ _ _ _-3'

Complementary strand must have right base pairs: 5'-TAACG-3'

An alternate way of writing this answer would be 3'-GCAAT-5'. This answer would still be correct! It would simply need to be flipped, as in the second step outlined above.

DNA is a double stranded molecule that is antiparallel, meaning the 5' end of one strand matches up with the 3' end of the other strand. Nitrogenous bases hold the strands together via hydrogen bonding. These bases are adenine (A), thymine (T), guanine (G), and cytosine (C). Adenine (A) can only pair with thymine (T), and guanine (G) can only pair with cytosine (C).

The correct answer presents two strands that are antiparallel and show proper binding patterns.

5'-CTAGAG-3'

3'-GATCTC-5'

All other answers have an error in base pairing or ordering.

Nucleic acids are one of the main biological macromolecules, and include DNA and RNA. A nucleotide is a DNA monomer, while a ribonucleotide is an RNA monomer. Numerous nucleotides are bonded together by phosphodiester bonds to form a single molecule of DNA. The pattern of nucleotides is used to store and transmit hereditary information. A nucleotide is composed of a phosphate group, a nitrogenous base, and a pentose sugar (deoxyribose).