DNA and RNA nucleotides are linked together through phosphodiester bonds. A strong covalent bond (ester bond) forms between the 3' carbon atom of the sugar pentose of one nucleotide and a phosphate group, and a second ester bond forms between the phosphate group and the 5' carbon atom of the sugar pentose of another nucleotide. This alternation of sugar and phosphate groups forms a strong backbone and is also the reason why DNA is antiparallel and forms in the 5' to 3' direction.

This question is designed to catch a) students who are not reading the question carefully, and b) students unsure of which nucleotides pair with which.

The correct answer is 29%, because cytosine pairs with guanine in a 1:1 ratio. If you answered 21%, then you likely thought the question was more complex than it was.

DNA and RNA nucleotides are linked together through phosphodiester bonds. A strong covalent bond (ester bond) forms between the 3' carbon atom of the sugar pentose of one nucleotide and a phosphate group, and a second ester bond forms between the phosphate group and the 5' carbon atom of the sugar pentose of another nucleotide. This alternation of sugar and phosphate groups forms a strong backbone and is also the reason why DNA is antiparallel and forms in the 5' to 3' direction.

This question is designed to catch a) students who are not reading the question carefully, and b) students unsure of which nucleotides pair with which.

The correct answer is 29%, because cytosine pairs with guanine in a 1:1 ratio. If you answered 21%, then you likely thought the question was more complex than it was.

DNA and RNA nucleotides are linked together through phosphodiester bonds. A strong covalent bond (ester bond) forms between the 3' carbon atom of the sugar pentose of one nucleotide and a phosphate group, and a second ester bond forms between the phosphate group and the 5' carbon atom of the sugar pentose of another nucleotide. This alternation of sugar and phosphate groups forms a strong backbone and is also the reason why DNA is antiparallel and forms in the 5' to 3' direction.

This question is designed to catch a) students who are not reading the question carefully, and b) students unsure of which nucleotides pair with which.

The correct answer is 29%, because cytosine pairs with guanine in a 1:1 ratio. If you answered 21%, then you likely thought the question was more complex than it was.

The correct answer is hydrogen bonding, and each nucleotide attracts its pairing mate because they have corresponding number of hydrogen bonds. Adenine is attracted to thymine to create two hydrogen bonds, and cytosine is attracted to guanine to form three hydrogen bonds. While phosphodiester bonds are very important in creating the strand of DNA, they are not the bond that keeps the two strands in the double helix structure.

DNA nucleotides all contain one of four possible nitrogen bases: adenine (A), thymine (T), cytosine (C), or guanine (G). In forming base pairs, an A must always pair with a T and a C must always pair with a G: \[A-T\], \[C-G\]. This means that for any DNA composition, the percent of adenine (A) must be equal to the percent of thymine (T) and, likewise, the percent of cytosine (C) must be equal to the percent of guanine (G). Looking across the answer choices, there is only one choice that satisfies this condition while also correctly summing to 100%. The choice with uracil can be eliminated immediately, since uracil only replaces thymine in RNA and is not present in DNA.

DNA nucleotides all contain one of four possible nitrogen bases: adenine (A), thymine (T), cytosine (C), or guanine (G). In forming base pairs, an A must always pair with a T and a C must always pair with a G: \[A-T\], \[C-G\]. This means that for any DNA composition, the percent of adenine (A) must be equal to the percent of thymine (T) and, likewise, the percent of cytosine (C) must be equal to the percent of guanine (G). Looking across the answer choices, there is only one choice that satisfies this condition while also correctly summing to 100%. The choice with uracil can be eliminated immediately, since uracil only replaces thymine in RNA and is not present in DNA.

DNA nucleotides all contain one of four possible nitrogen bases: adenine (A), thymine (T), cytosine (C), or guanine (G). In forming base pairs, an A must always pair with a T and a C must always pair with a G: \[A-T\], \[C-G\]. This means that for any DNA composition, the percent of adenine (A) must be equal to the percent of thymine (T) and, likewise, the percent of cytosine (C) must be equal to the percent of guanine (G). Looking across the answer choices, there is only one choice that satisfies this condition while also correctly summing to 100%. The choice with uracil can be eliminated immediately, since uracil only replaces thymine in RNA and is not present in DNA.