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KAA-Lecture 3- DNA Replication 8_14.pdf Flashcards
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KAA-Lecture 3- DNA Replication 8_14.pdf Flashcards
KAA-Lecture 3- DNA Replication 8_14.pdf Flashcards
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1
Question
What occurs during the S phase of mitosis?
Answer
DNA replication occurs during the S phase of mitosis.
2
Question
Why do cells divide?
Answer
Cells divide for many reasons, for example, to replace old, dead, or damaged cells.
3
Question
What are examples of cells with short lifespans?
Answer
Examples of cells with short lifespans include skin cells and blood cells.
4
Question
What is one reason cells divide in living organisms?
Answer
Cells divide so living things can grow.
5
Question
What happens when an organism grows in terms of cell size and number?
Answer
When an organism grows, the cells themselves are not getting larger; rather, cells are dividing to produce more and more cells.
6
Question
What is the average lifespan of erythrocytes (red blood cells)?
Answer
The average lifespan of erythrocytes (red blood cells) is 120 days.
7
Question
What is the average lifespan of white blood cells (WBCs)?
Answer
The average lifespan of white blood cells (WBCs) is 5 to 21 days.
8
Question
What triggers an increase in the number of white blood cells?
Answer
The number of WBCs increases in response to infection.
9
Question
What is the semi-conservative DNA replication model?
Answer
In the semi-conservative DNA replication model, the two strands of DNA unwind from each other and each acts as a template for synthesis of a new complementary strand.
10
Question
What does DNA replication produce?
Answer
DNA replication produces two complete double helices from the original DNA molecule.
11
Question
How does each resulting DNA helix compare to the parental DNA?
Answer
Each resulting DNA helix is identical in nucleotide sequence to the parental DNA.
12
Question
What are the steps in DNA replication?
Answer
The steps in DNA replication are Initiation, Elongation, and Termination.
13
Question
What is a replication fork?
Answer
A replication fork is the area where the double-stranded DNA molecule is unzipped into two single strands.
14
Question
What enzyme is responsible for unwinding DNA during replication?
Answer
DNA helicase is the enzyme responsible for unwinding DNA during replication.
15
Question
What is the origin of replication?
Answer
The origin of replication is a particular sequence of DNA at which replication is initiated, typically composed of an AT-rich sequence.
16
Question
How does DNA helicase function during DNA replication?
Answer
DNA helicase disrupts the hydrogen bonding between base pairs to separate the strands into a Y shape known as the replication fork.
17
Question
What direction do DNA polymerases add nucleotides?
Answer
DNA polymerases can only add nucleotides to the 3' end.
18
Question
How do leading and lagging strands differ in DNA replication?
Answer
The leading strand's DNA polymerase moves along the 3' to 5' strand assembling the new strand in the 5' to 3' direction, while the lagging strand's polymerase replicates it in short segments called Okazaki fragments.
19
Question
What are Okazaki fragments?
Answer
Okazaki fragments are short segments that make up the lagging strand during DNA replication.
20
Question
Who won the Nobel Prize in Chemistry in 1993 for work related to PCR?
Answer
Kary Mullis won the Nobel Prize in Chemistry in 1993.
21
Question
What applications has PCR revolutionized in molecular biology?
Answer
PCR has revolutionized molecular biology by enabling the ability to make millions of copies of specific sequences.
22
Question
What are some applications of PCR in genetic testing?
Answer
Applications of PCR in genetic testing include mapping of genomes, tissue typing for organ transplants, oncogene testing, and diagnosis of cancer.
23
Question
What does the term 'in vitro' refer to in the context of PCR?
Answer
In vitro refers to processes that occur in a controlled laboratory environment, such as a test tube.
24
Question
What does 'in vivo' mean?
Answer
In vivo is Latin for 'within the living'.
25
Question
What is the monomeric subunit of DNA?
Answer
The monomeric subunit of DNA is a nucleotide.
26
Question
What are the four bases found in DNA?
Answer
The four bases found in DNA are adenine (A), thymine (T), guanine (G), and cytosine (C).
27
Question
What was used in early PCR that was not thermostable?
Answer
Early PCR used Klenow fragment or T4 DNA polymerase, which were not thermostable.
28
Question
What is Taq polymerase and where does it come from?
Answer
Taq polymerase is an enzyme that can withstand high temperatures required for PCR, named after the thermophilic bacterium Thermus aquaticus.
29
Question
What is the error rate of Taq polymerase?
Answer
The error rate of Taq polymerase is approximately 1 in 9,000 nucleotides.
30
Question
What is the role of the PCR buffer, specifically MgCl2?
Answer
The PCR buffer, including MgCl2, is essential for the reaction conditions in PCR.