Quiz In Nucleic Acid Structures
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Which of the following is NOT found in DNA?
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Uracil
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Thymine
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Adenine
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Cytosine
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About This Quiz
This quiz on Nucleic Acid Structures tests knowledge on DNA and RNA components, their structures, and bonding. It assesses understanding of nucleotide polymerization and complementary base pairing, crucial for students and professionals in molecular biology.
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- 2.
In addition to the standard organic elements carbon, hydrogen and oxygen, nucleic acids also contain
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Calcium
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Chloride
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Sulfur
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Phosphorus
Correct Answer
A. PhosphorusExplanation
Nucleic acids, such as DNA and RNA, are composed of nucleotide building blocks. These nucleotides consist of a sugar molecule, a phosphate group, and a nitrogenous base. Phosphorus is a crucial component of the phosphate group, which forms the backbone of the nucleic acid molecule. It plays a vital role in the structure and function of nucleic acids by providing stability and allowing for the formation of phosphodiester bonds between nucleotides. Therefore, nucleic acids contain phosphorus as an essential element.Rate this question:
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- 3.
What holds the DNA double strands together?
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Hydrophobic interactions
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H-bonds
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Peptide bonds
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Van der Waal's forces
Correct Answer
A. H-bondsExplanation
H-bonds hold the DNA double strands together. Hydrophobic interactions occur between nonpolar molecules, peptide bonds are responsible for linking amino acids in proteins, and van der Waal's forces are weak intermolecular forces. However, H-bonds play a crucial role in stabilizing the DNA double helix structure by forming between complementary base pairs (adenine with thymine and cytosine with guanine). These hydrogen bonds provide the necessary strength and specificity for DNA replication and genetic information transfer.Rate this question:
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- 4.
Choose THREE correct answers. Which of the following is found in RNA
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Cytosine
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Guanine
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Thymine
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Uracil
Correct Answer(s)
A. Cytosine
A. Guanine
A. UracilExplanation
RNA is a nucleic acid that plays a crucial role in protein synthesis. It is composed of nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base. The four nitrogenous bases found in RNA are adenine, cytosine, guanine, and uracil. Thymine is not found in RNA, it is instead found in DNA. Therefore, the correct answers are cytosine, guanine, and uracil.Rate this question:
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- 5.
A nucleotide has how many components?
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1
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2
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3
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4
Correct Answer
A. 3Explanation
A nucleotide has three components: a sugar molecule (either ribose or deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). These components are bonded together to form the basic building blocks of DNA and RNA.Rate this question:
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- 6.
DNA is a polymer of:
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Nucleic acid
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Nucleoside
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Nucleotide
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Bases
Correct Answer
A. NucleotideExplanation
DNA is a polymer of nucleotides. Nucleotides are the building blocks of DNA, consisting of a sugar molecule, a phosphate group, and a nitrogenous base. These nucleotides are linked together through phosphodiester bonds to form a long chain, which is the DNA molecule. The sequence of nucleotides in DNA carries genetic information and determines the characteristics of an organism.Rate this question:
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- 7.
Nucleotides are linked together via:
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H-bonds
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3',5'-phosphoester bonds
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3',5'-phosphodiester bonds
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N1-glycosidic bonds
Correct Answer
A. 3',5'-phosphodiester bondsExplanation
Nucleotides are linked together via 3',5'-phosphodiester bonds. These bonds form between the 3' carbon of one nucleotide and the 5' carbon of the next nucleotide in the DNA or RNA chain. This linkage creates a sugar-phosphate backbone that provides stability to the DNA or RNA molecule. The phosphodiester bond involves the removal of a water molecule and the formation of a covalent bond between the phosphate group and the sugar molecule. This bond is essential for the integrity and structure of nucleic acids.Rate this question:
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- 8.
The percent of adenine in a double-stranded DNA is 38. What is the percent of uracil in that DNA?
Correct Answer
0Explanation
Since uracil is not present in DNA, the percent of uracil in the given DNA is 0. Uracil is only found in RNA, not DNA. DNA contains adenine, guanine, cytosine, and thymine as its bases, while RNA contains adenine, guanine, cytosine, and uracil. Therefore, the percent of uracil in the given DNA is 0%.Rate this question:
- 9.
What is the base sequence of the DNA strand that would be complementary to the following single-stranded DNA molecule? 5' GGATCTGATCCAGTCA 3'
Correct Answer
3' CCTAGACTAGGTCAGT 5'Explanation
The base sequence of the DNA strand that would be complementary to the given single-stranded DNA molecule is 3' CCTAGACTAGGTCAGT 5'. In DNA, adenine (A) pairs with thymine (T) and cytosine (C) pairs with guanine (G). Therefore, to find the complementary sequence, we need to replace each base with its complementary base.Rate this question:
- 10.
The percent of cytosine in a double-stranded DNA is 21. What is the percent of thymine in that DNA?
Correct Answer
29%Explanation
Since DNA is a double-stranded molecule, the amount of cytosine should be equal to the amount of guanine, and the amount of adenine should be equal to the amount of thymine. Therefore, if the percent of cytosine is 21, the percent of guanine is also 21. Since the total percentage of the four bases (cytosine, guanine, adenine, and thymine) should add up to 100%, and the percent of cytosine and guanine is already 42%, the remaining percentage must be split equally between adenine and thymine. Hence, the percent of thymine is 29%.Rate this question:
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Mar 22, 2023Quiz Edited by
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Apr 20, 2014Quiz Created by
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