AP Bio 6.2 Replication of DNA
39 flashcards covering AP Bio 6.2 Replication of DNA for the AP-BIOLOGY Unit 6 section.
The topic of DNA replication is a critical component of the AP Biology curriculum, specifically outlined in the College Board's AP Biology Course Framework. This section covers the mechanisms by which DNA is duplicated, including key enzymes such as DNA polymerase, the roles of leading and lagging strands, and the importance of accuracy in replication for genetic fidelity. Understanding these processes is essential for grasping how genetic information is passed on during cell division.
In practice exams and competency assessments, questions on DNA replication often involve multiple-choice formats or short answer prompts that require students to explain specific steps or identify the functions of various enzymes involved. A common pitfall is misidentifying the roles of leading versus lagging strands or overlooking the significance of Okazaki fragments. Students may also confuse the directionality of replication, which can lead to incorrect answers.
A practical tip is to consistently visualize the replication process with diagrams, as this can help clarify the spatial relationships and functions of the different components involved.
Terms (39)
- 01
What is the role of helicase in DNA replication?
Helicase unwinds the DNA double helix by breaking hydrogen bonds between the base pairs, allowing the strands to separate for replication (College Board AP CED).
- 02
What enzyme synthesizes new DNA strands during replication?
DNA polymerase synthesizes new DNA strands by adding nucleotides complementary to the template strand (College Board AP CED).
- 03
What is the function of primase in DNA replication?
Primase synthesizes a short RNA primer that provides a starting point for DNA polymerase to begin DNA synthesis (College Board AP CED).
- 04
How does DNA replication differ between prokaryotes and eukaryotes?
In prokaryotes, DNA replication occurs in the cytoplasm and is typically faster, while in eukaryotes, it occurs in the nucleus and involves multiple origins of replication (College Board AP CED).
- 05
What is the significance of the leading and lagging strands in DNA replication?
The leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments (Okazaki fragments) due to the antiparallel nature of DNA (College Board AP CED).
- 06
What are Okazaki fragments?
Okazaki fragments are short segments of DNA synthesized on the lagging strand during DNA replication, which are later joined by DNA ligase (College Board AP CED).
- 07
What is the role of DNA ligase in DNA replication?
DNA ligase joins Okazaki fragments on the lagging strand by forming phosphodiester bonds, completing the DNA strand (College Board AP CED).
- 08
When does DNA replication occur in the cell cycle?
DNA replication occurs during the S phase of interphase, prior to cell division (College Board AP CED).
- 09
What is the function of single-strand binding proteins during DNA replication?
Single-strand binding proteins stabilize the unwound DNA strands during replication, preventing them from re-annealing (College Board AP CED).
- 10
What is the role of topoisomerase in DNA replication?
Topoisomerase alleviates the torsional strain created ahead of the replication fork by making temporary cuts in the DNA strands (College Board AP CED).
- 11
What is the direction of DNA synthesis during replication?
DNA synthesis occurs in the 5' to 3' direction, meaning nucleotides are added to the 3' end of the growing strand (College Board AP CED).
- 12
What is the purpose of the RNA primer in DNA replication?
The RNA primer provides a free 3' hydroxyl group for DNA polymerase to initiate DNA synthesis (College Board AP CED).
- 13
How often are DNA polymerases proofread during replication?
DNA polymerases proofread newly synthesized DNA, correcting errors in nucleotide pairing, which occurs continuously during synthesis (College Board AP CED).
- 14
What happens if DNA replication is not accurately completed?
If DNA replication is not accurate, it can lead to mutations, which may affect cell function and contribute to diseases such as cancer (College Board AP CED).
- 15
What is semi-conservative replication?
Semi-conservative replication is the method by which DNA replicates, where each new DNA molecule consists of one original strand and one newly synthesized strand (College Board AP CED).
- 16
What is the role of the replication fork?
The replication fork is the area where the DNA double helix is unwound and separated into two single strands for replication (College Board AP CED).
- 17
What are the components of the DNA replication machinery?
The DNA replication machinery includes helicase, primase, DNA polymerases, ligase, and single-strand binding proteins (College Board AP CED).
- 18
What is the significance of telomeres in DNA replication?
Telomeres protect the ends of chromosomes from deterioration and prevent the loss of important genetic information during replication (College Board AP CED).
- 19
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 (College Board AP CED).
- 20
What is the difference between leading and lagging strand synthesis?
Leading strand synthesis is continuous, while lagging strand synthesis occurs in short, discontinuous segments (Okazaki fragments) (College Board AP CED).
- 21
How does the structure of DNA contribute to its replication?
The double helix structure of DNA allows for complementary base pairing, enabling accurate replication of genetic information (College Board AP CED).
- 22
What is the role of the origin of replication?
The origin of replication is the specific location on the DNA where replication begins, allowing the replication machinery to assemble (College Board AP CED).
- 23
What are the consequences of mutations during DNA replication?
Mutations can lead to changes in protein function, potentially causing diseases or altering traits in organisms (College Board AP CED).
- 24
How do eukaryotic cells ensure accurate DNA replication?
Eukaryotic cells utilize multiple DNA polymerases, checkpoints, and repair mechanisms to ensure accurate DNA replication (College Board AP CED).
- 25
What is the role of DNA polymerase III in prokaryotic DNA replication?
DNA polymerase III is the primary enzyme responsible for synthesizing new DNA strands in prokaryotes during replication (College Board AP CED).
- 26
What is the significance of the 3' to 5' exonuclease activity of DNA polymerases?
The 3' to 5' exonuclease activity allows DNA polymerases to remove incorrectly incorporated nucleotides, enhancing replication accuracy (College Board AP CED).
- 27
What is the function of the sliding clamp in DNA replication?
The sliding clamp holds DNA polymerase in place on the DNA template, increasing the efficiency of DNA synthesis (College Board AP CED).
- 28
What is the role of the replication bubble in DNA replication?
The replication bubble forms as DNA unwinds, allowing replication to occur simultaneously at multiple sites along the DNA molecule (College Board AP CED).
- 29
What is the impact of DNA replication errors on genetic diversity?
DNA replication errors can introduce mutations that contribute to genetic diversity, which is essential for evolution (College Board AP CED).
- 30
What is the significance of the 5' cap and poly-A tail in mRNA processing?
The 5' cap and poly-A tail protect mRNA from degradation and assist in ribosome binding during translation (College Board AP CED).
- 31
What is the role of RNA in DNA replication?
RNA primers are necessary for DNA polymerase to initiate DNA synthesis, as DNA polymerase cannot start synthesis without a primer (College Board AP CED).
- 32
How do mutations during DNA replication affect evolution?
Mutations can create new alleles that may provide advantages or disadvantages, influencing natural selection and evolution (College Board AP CED).
- 33
What is the role of the 5' to 3' directionality in DNA replication?
The 5' to 3' directionality is crucial because DNA polymerases can only add nucleotides to the 3' end of a growing DNA strand (College Board AP CED).
- 34
What is the function of the DNA replication checkpoint?
The DNA replication checkpoint ensures that DNA is accurately replicated before the cell cycle continues, preventing the propagation of errors (College Board AP CED).
- 35
What are the consequences of telomerase activity in somatic cells?
Telomerase activity in somatic cells is typically low, leading to gradual telomere shortening and cellular aging (College Board AP CED).
- 36
What is the role of the TATA box in transcription initiation?
The TATA box is a DNA sequence that helps position RNA polymerase at the start of a gene for transcription (College Board AP CED).
- 37
What is the impact of environmental factors on DNA replication fidelity?
Environmental factors such as radiation and chemicals can increase the rate of mutations during DNA replication, affecting genetic stability (College Board AP CED).
- 38
How does the cell repair DNA replication errors?
Cells utilize mismatch repair mechanisms to correct errors made during DNA replication, maintaining genetic integrity (College Board AP CED).
- 39
What is the relationship between DNA replication and cell division?
DNA replication is essential for cell division, as it ensures that each daughter cell receives an identical copy of the genetic material (College Board AP CED).