Questions and Answers
What molecules make up the rungs of the DNA ladder and which make up the vertical sides?
The rungs are made up of complementary nitrogenous bases and the sides are made up of pentose sugars and phosphate groups.
How do we all look different from one another if every human's DNA has the same basic structure?
Everyone has a different sequence of nitrogen bases in their DNA which makes them unique.
What is the complementary sequence for the DNA strand 5′-3′ ATGGAATT?
3'-TACCTTAA-5'
The pairing of ________ is responsible for the diameter of a DNA double helix.
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In order to change ________ of an organism, one would need to change the DNA sequence.
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If DNA contains 23 percent A, what would be the percentage of G?
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Genetic information is stored in the ________ of a DNA molecule.
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Accurate copying and expression of DNA are required for ________ to function as a storage molecule for genetic information.
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The sugar-phosphate backbone of a DNA double helix is joined together by ________ bonds.
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What does semi-conservative DNA replication mean?
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DNA replication requires an enzyme.
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What are the building blocks of DNA?
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DNA replication requires energy.
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Which molecule provides instructions about the order of nucleotides in the new polymer?
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What is the short piece of nucleic acid needed by DNA polymerase to start making a DNA copy?
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Which enzyme separates the two complementary strands of DNA?
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Which enzyme attaches complementary bases to the template strand?
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Which component is later replaced with DNA bases during replication?
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What occurs if DNA polymerase stops working during DNA replication?
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What enzyme is responsible for proofreading our DNA?
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Each strand of a parent DNA molecule serves as the template for __________ in a daughter molecule.
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The enzyme ________ adds new bases to a growing DNA strand.
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When does nucleotide excision repair occur?
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In which direction does DNA replication take place?
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What does the enzyme helicase do?
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In DNA ________, the newest base is reread before another is added to ensure accurate copying.
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The anchor used to start a new DNA strand is called a ________.
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What mode of replication did Meselson and Stahl's experiments prove DNA replicates by?
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Study Notes
DNA Structure and Replication Key Concepts
- The rungs of a DNA double helix are composed of complementary nitrogenous bases, while the sides consist of pentose sugars and phosphate groups.
- Unique physical traits arise from differing sequences of nitrogen bases within individual DNA, forming each person's "genetic code."
- The complementary sequence for a DNA strand (5′-3′) such as ATGGAATT is 3'-TACCTTAA-5'.
- The diameter of the DNA double helix is maintained by pairing purines with pyrimidines.
- Altering an organism's observable characteristics requires modifications in its DNA sequence.
- If a species' DNA contains 23% adenine (A), the guanine (G) content will be 27% due to base pairing rules (A-T and C-G).
- Genetic information is encoded in the specific sequence of nucleotides in DNA.
- For DNA to function effectively as a genetic information storage molecule, accurate replication and expression of the sequence are essential.
- The sugar-phosphate backbone of DNA is linked by phosphodiester bonds.
- DNA replication is semi-conservative; each new strand retains one original strand and one new strand.
- DNA replication requires the enzyme DNA polymerase and also necessitates energy.
- Instructions for nucleotide sequence during DNA replication are provided by the DNA itself.
- A primer — a short piece of DNA or RNA — is needed for DNA polymerase to initiate synthesis by binding nucleotides.
- Helicase is the enzyme that separates complementary DNA strands during replication.
- DNA polymerase is responsible for attaching complementary bases to the template strand.
- RNA primers are later substituted with DNA bases during the replication process.
- If DNA polymerase fails to function, no new nitrogenous bases would be added, halting replication.
- DNA polymerase also proofreads DNA for mistakes during replication; errors might lead to serious issues like cancer.
- Each parental DNA strand serves as a template to produce complementary strands in daughter DNA molecules, which bond post-replication.
- DNA polymerase adds new bases to the growing strand of DNA.
- Nucleotide excision repair involves cutting the DNA strand around an incorrect base for correction.
- DNA replication occurs in the 5' to 3' direction.
- The helicase enzyme's role includes separating the two strands of the DNA double helix.
- Proofreading in DNA occurs as the latest base is re-read before adding another to ensure accuracy in copying.
- Primers act as anchors necessary for starting new DNA strands.
- Semiconservative replication of DNA was demonstrated through Meselson and Stahl's experimental findings.
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Description
Test your knowledge on the fundamental concepts of DNA structure and replication with these flashcards. Understand the composition of the DNA double helix and explore its unique properties as you prepare for your studies in molecular biology.
