Which of the following statements about DNA is incorrect?ANSWERThe alternating sugars and phosphate molecules of the DNA backbone bond together via phosphodiester bonds.DNA is a long, single-stranded molecule that curves into a helix, and the set pairings of the bases ensure that there is always a purine across from another purine and a pyrimidine across from another pyrimidine.The nitrogen base adenine always pairs with thymine, and guanine always pairs with cytosine.DNA has an antiparallel arrangement.
Question
Which of the following statements about DNA is incorrect?ANSWERThe alternating sugars and phosphate molecules of the DNA backbone bond together via phosphodiester bonds.DNA is a long, single-stranded molecule that curves into a helix, and the set pairings of the bases ensure that there is always a purine across from another purine and a pyrimidine across from another pyrimidine.The nitrogen base adenine always pairs with thymine, and guanine always pairs with cytosine.DNA has an antiparallel arrangement.
Solution
To determine which statement about DNA is incorrect, let's analyze each one step by step:
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"The alternating sugars and phosphate molecules of the DNA backbone bond together via phosphodiester bonds."
- This statement is correct. The backbone of DNA is composed of alternating sugar (deoxyribose) and phosphate groups, which are connected by phosphodiester bonds.
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"DNA is a long, single-stranded molecule that curves into a helix, and the set pairings of the bases ensure that there is always a purine across from another purine and a pyrimidine across from another pyrimidine."
- This statement is incorrect. DNA is a double-stranded molecule that forms a double helix. The base pairing rules ensure that a purine (adenine or guanine) pairs with a pyrimidine (thymine or cytosine), not another purine or pyrimidine.
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"The nitrogen base adenine always pairs with thymine, and guanine always pairs with cytosine."
- This statement is correct. In DNA, adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C).
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"DNA has an antiparallel arrangement."
- This statement is correct. The two strands of DNA run in opposite directions, meaning they are antiparallel.
Therefore, the incorrect statement is: "DNA is a long, single-stranded molecule that curves into a helix, and the set pairings of the bases ensure that there is always a purine across from another purine and a pyrimidine across from another pyrimidine."
Similar Questions
Which of the following statements is incorrect regarding DNA and RNA?DNA is double stranded, and RNA is a single strand.They each contain a slightly different sugar molecule.One of the bases is different.All of the above are correct.
In a DNA molecule, ______ bonds form between nitrogenous bases, such that A (adenine) pairs with its complement ______, and G (guanine) pairs with its complement ______.Multiple choice question.hydrogen; T (thymine); C (cytosine)hydrogen; G (guanine); T (thymine)ionic; C (cytosine); T (thymine)ionic; T (thymine); G (guanine)
Which of the following is true of the DNA molecule? A. Vorm 'n dubbel heliks met twee komplimentêre stringe. / Forms a double helix of two complimentary strands B. Die suiker wat in die nukleotiede gevind word is ribose. / The sugar found in the nucleotides is ribose C. Nukleotiede sluit in adenien, guanien, sitosien en urasiel. / Nucleotides include adenine, guanine, cytosine, and uracil D. Al die bogenoemde. / All of the above
Which of the following is not true of all naturally occurring DNA? A. Deoxyribose units are connected by 3',5'-phosphodiester bonds. B. The ratio A+T/G+C is constant for all natural DNAs. C. Two hydrogen bonds form between A and T. D. The two complementary strands are antiparallel. E. The amount of A always equals the amount of T.
Students are studying a model fragment of a DNA double helix. In the model they can see nucleotides linked together by 16 phosphodiester bonds, 9 stacked pairs of nitrogenous bases and 3 of the nitrogenous bases are thymine.This DNA double helix fragment therefore contains:Select one alternative:16 deoxyribose molecules and 6 adenine nitrogenous bases.18 deoxyribose molecules and 6 adenine nitrogenous bases.9 deoxyribose molecules and 3 adenine nitrogenous bases.18 deoxyribose molecules and 3 adenine nitrogenous bases.
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