Bio 101 DNA Replication
37 flashcards covering Bio 101 DNA Replication for the BIOLOGY-101 Genetics & Molecular Bio section.
DNA replication is a fundamental biological process that ensures genetic information is accurately copied and passed on during cell division. It is a key topic in the Introductory Biology I curriculum, as outlined by the National Science Teachers Association (NSTA). Understanding the mechanisms of DNA replication, including the roles of enzymes like DNA polymerase and helicase, is essential for grasping the principles of genetics and molecular biology.
In practice exams and competency assessments, questions on DNA replication often focus on the steps involved in the process, the enzymes required, and the significance of replication fidelity. Common question styles include multiple-choice questions that require identifying the correct sequence of events or matching enzymes to their functions. A frequent pitfall is misunderstanding the difference between leading and lagging strand synthesis, which can lead to errors in answering questions about replication directionality and Okazaki fragments.
One concrete tip that is often overlooked is the importance of understanding the implications of errors in DNA replication, which can lead to mutations and impact genetic stability.
Terms (37)
- 01
What is the role of DNA helicase in DNA replication?
DNA helicase unwinds the double-stranded DNA by breaking the hydrogen bonds between the base pairs, allowing the replication fork to form (Campbell Biology, chapter on DNA replication).
- 02
What is the function of DNA polymerase during replication?
DNA polymerase synthesizes new DNA strands by adding nucleotides complementary to the template strand, ensuring accurate replication (Campbell Biology, chapter on DNA replication).
- 03
What are the leading and lagging strands in DNA replication?
The leading strand is synthesized continuously in the same direction as the replication fork, while the lagging strand is synthesized discontinuously in short segments called Okazaki fragments (Campbell Biology, chapter on DNA replication).
- 04
How does DNA replication ensure accuracy?
DNA replication ensures accuracy through the proofreading function of DNA polymerase, which can detect and correct mismatched nucleotides (Campbell Biology, chapter on DNA replication).
- 05
What is the significance of RNA primers in DNA replication?
RNA primers provide a starting point for DNA polymerase to begin synthesis, as DNA polymerase can only add nucleotides to an existing strand (Campbell Biology, chapter on DNA replication).
- 06
What enzyme removes RNA primers during DNA replication?
DNA polymerase I removes RNA primers and replaces them with DNA nucleotides during DNA replication (Campbell Biology, chapter on DNA replication).
- 07
What is meant by the term 'replication fork'?
The replication fork is the Y-shaped region where the DNA double helix is unwound and separated into two single strands for replication (Campbell Biology, chapter on DNA replication).
- 08
How often does DNA replication occur in a cell cycle?
DNA replication occurs once during the S phase of the cell cycle, ensuring that each daughter cell receives an identical copy of the DNA (Campbell Biology, chapter on cell cycle).
- 09
What is the role of single-strand binding proteins in DNA replication?
Single-strand binding proteins stabilize the unwound single-stranded DNA during replication, preventing it from re-annealing or forming secondary structures (Campbell Biology, chapter on DNA replication).
- 10
What are Okazaki fragments and when are they formed?
Okazaki fragments are short segments of DNA synthesized on the lagging strand during DNA replication, formed because the lagging strand is synthesized discontinuously (Campbell Biology, chapter on DNA replication).
- 11
What is the function of DNA ligase in DNA replication?
DNA ligase joins Okazaki fragments together by forming phosphodiester bonds, completing the continuous DNA strand on the lagging strand (Campbell Biology, chapter on DNA replication).
- 12
What initiates the process of DNA replication?
DNA replication is initiated at specific locations called origins of replication, where the DNA double helix is unwound (Campbell Biology, chapter on DNA replication).
- 13
What is the difference between prokaryotic and eukaryotic DNA replication?
Prokaryotic DNA replication occurs in a circular chromosome and typically has a single origin, while eukaryotic replication occurs in linear chromosomes with multiple origins (Campbell Biology, chapter on DNA replication).
- 14
What is the role of topoisomerase in DNA replication?
Topoisomerase relieves the tension and supercoiling that occurs ahead of the replication fork by making temporary cuts in the DNA strands (Campbell Biology, chapter on DNA replication).
- 15
How does the structure of DNA contribute to its replication?
The antiparallel structure of DNA allows for the complementary base pairing necessary for accurate replication, with each strand serving as a template (Campbell Biology, chapter on DNA replication).
- 16
What are the consequences of errors in DNA replication?
Errors in DNA replication can lead to mutations, which may result in changes to the protein coding sequences and potentially affect cell function (Campbell Biology, chapter on DNA replication).
- 17
What is semi-conservative replication?
Semi-conservative replication refers to the process where each new DNA molecule consists of one original strand and one newly synthesized strand (Campbell Biology, chapter on DNA replication).
- 18
What are the key differences between DNA and RNA?
DNA contains deoxyribose sugar and is double-stranded, while RNA contains ribose sugar and is typically single-stranded (Campbell Biology, chapter on nucleic acids).
- 19
What is the role of primase in DNA replication?
Primase synthesizes short RNA primers that provide a starting point for DNA polymerase to begin DNA synthesis (Campbell Biology, chapter on DNA replication).
- 20
What is the role of the sliding clamp in DNA replication?
The sliding clamp holds DNA polymerase in place on the DNA strand, increasing its processivity during replication (Campbell Biology, chapter on DNA replication).
- 21
How does DNA replication differ in eukaryotes compared to prokaryotes?
Eukaryotic DNA replication is more complex, involving multiple origins of replication and a larger amount of DNA packaged in chromosomes compared to prokaryotes (Campbell Biology, chapter on DNA replication).
- 22
What happens during the termination phase of DNA replication?
During termination, replication ends when the replication forks meet, and any remaining RNA primers are removed and replaced with DNA (Campbell Biology, chapter on DNA replication).
- 23
What is the importance of telomeres in DNA replication?
Telomeres protect the ends of linear chromosomes from deterioration and prevent the loss of important genetic information during replication (Campbell Biology, chapter on DNA replication).
- 24
What is the function of exonuclease activity in DNA polymerase?
Exonuclease activity allows DNA polymerase to remove incorrectly paired nucleotides, enhancing the fidelity of DNA replication (Campbell Biology, chapter on DNA replication).
- 25
How do mutations arise during DNA replication?
Mutations can arise from errors in DNA replication that are not corrected by proofreading mechanisms, leading to permanent changes in the DNA sequence (Campbell Biology, chapter on DNA replication).
- 26
What is the significance of the 5' to 3' directionality in DNA replication?
DNA strands are synthesized in the 5' to 3' direction, meaning nucleotides can only be added to the 3' end of the growing strand (Campbell Biology, chapter on DNA replication).
- 27
What is the purpose of the origin of replication?
The origin of replication is the specific site on the DNA molecule where replication begins, allowing for the separation of strands (Campbell Biology, chapter on DNA replication).
- 28
What is the role of the replication bubble?
The replication bubble forms as the DNA unwinds and separates, allowing replication to occur simultaneously on both strands (Campbell Biology, chapter on DNA replication).
- 29
How do cells ensure that DNA replication is tightly regulated?
Cells regulate DNA replication through checkpoints in the cell cycle, ensuring that replication occurs only when conditions are favorable (Campbell Biology, chapter on the cell cycle).
- 30
What is the role of DNA repair mechanisms post-replication?
DNA repair mechanisms fix any errors or damage in the DNA after replication, maintaining genomic stability (Campbell Biology, chapter on DNA repair).
- 31
What are the consequences of telomerase activity?
Telomerase extends telomeres, allowing for continued cell division and is often active in cancer cells, contributing to their immortality (Campbell Biology, chapter on DNA replication).
- 32
What is the significance of complementary base pairing in DNA replication?
Complementary base pairing ensures that the correct nucleotides are added to the growing DNA strand, maintaining genetic fidelity (Campbell Biology, chapter on DNA replication).
- 33
How does the cell ensure that DNA replication is accurate?
The cell employs proofreading by DNA polymerases and mismatch repair systems to correct errors during and after DNA replication (Campbell Biology, chapter on DNA replication).
- 34
What is the function of the 3' to 5' exonuclease activity in DNA polymerase?
The 3' to 5' exonuclease activity allows DNA polymerase to remove incorrectly paired nucleotides, enhancing replication accuracy (Campbell Biology, chapter on DNA replication).
- 35
What is the role of the replication fork in DNA replication?
The replication fork is the area where the DNA is actively being unwound and replicated, facilitating the synthesis of new DNA strands (Campbell Biology, chapter on DNA replication).
- 36
What is the significance of the S phase in the cell cycle?
The S phase is the part of the cell cycle where DNA replication occurs, ensuring that each daughter cell receives a complete set of chromosomes (Campbell Biology, chapter on the cell cycle).
- 37
What is the role of nucleotides in DNA replication?
Nucleotides are the building blocks of DNA, providing the necessary components for synthesizing new DNA strands during replication (Campbell Biology, chapter on nucleic acids).