219 Questions
In DNA, how is the second strand oriented in relation to the first strand?
Antiparallel
What is the correct name for the base sugar with the phosphate in DNA?
Nucleotide
What is the correct nomenclature for the base bound to the sugar in DNA?
Nitrogen base
What is the number of hydrogen bonds formed between adenine and thymine in DNA?
Two
Which nitrogen base pair is easier to denature in DNA?
Adenine and Thymine
Which carbon on the deoxyribose in DNA is usually replaced by a normal hydrogen?
Fifth carbon
What are the two types of nitrogen-containing bases in DNA?
Purines and pyrimidines
How many cyclic structures do purines have in DNA?
Two
How many carbon atoms are in the sugar of DNA?
Five
Which carbon on the deoxyribose in DNA is replaced by a normal hydrogen?
Second carbon
What is the correct nomenclature for the base bound to the sugar in DNA?
Nucleoside
What is the correct name for the base sugar with the phosphate in DNA?
Nucleotide
Which nitrogen base pair is easier to denature in DNA?
Adenine-Thymine
In DNA, how is the second strand oriented in relation to the first strand?
Antiparallel
Which type of bond connects the sugar and phosphate backbones in DNA?
Covalent bond
What is the number of hydrogen bonds formed between adenine and thymine in DNA?
2
What is the correct name for the base sugar with the phosphate in RNA?
Nucleotide
What is the correct nomenclature for the base bound to the sugar in RNA?
Nucleoside
Which nitrogen base pair is more stable in DNA?
Guanine-Cytosine
Which of the following is a key difference between DNA and RNA?
DNA has deoxyribose sugar, while RNA has ribose sugar
Which type of RNA is the most predominant in each cell for making proteins?
rRNA
How many hydrogen bonds are formed between cytosine and guanine in DNA?
Three
Which nitrogen base is replaced by uracil in RNA?
Thymine
Which type of RNA is responsible for carrying amino acids to the ribosome during protein synthesis?
tRNA
Which type of RNA is involved in the assembly of ribosomes?
rRNA
Which type of RNA is involved in the regulation of gene expression?
microRNA
In DNA, which carbon on the sugar molecule is missing an oxygen atom?
Second carbon
Which type of RNA is responsible for carrying the genetic information from the DNA to the ribosome for protein synthesis?
mRNA
How many hydrogen bonds are formed between adenine and thymine in DNA?
Two
What is the main difference in DNA packaging between prokaryotes and eukaryotes?
Prokaryotes use supercoiling, while eukaryotes use histones
What is the function of supercoiling in DNA packaging?
To shorten the DNA and make it fit into the cell
What happens when a negative supercoil is introduced in DNA?
Tension is introduced and the DNA twists around itself
What happens when a positive supercoil is introduced in DNA?
Tension is introduced and the DNA twists around itself
What is the role of topoisomerases in DNA packaging?
To introduce or remove supercoils in DNA
What is the main difference between topoisomerase I and topoisomerase II?
Topoisomerase I makes a single strand break, while topoisomerase II makes a double strand break
What is the main difference in DNA structure between prokaryotes and eukaryotes?
Prokaryotes have circular DNA, while eukaryotes have linear DNA
What is the main function of coding DNA in prokaryotes?
To make proteins
What is the main function of non-coding DNA in eukaryotes?
Regulatory functions leading to alternative splicing
What is the main advantage of DNA supercoiling in prokaryotes?
Efficient packaging of DNA into a small cell
What is the major way in which DNA is packaged into the cell in prokaryotes?
By using topoisomerases
What are the yellow parts in the picture called?
Histones
How many times does the DNA wrap around the histones in a nucleosome?
Two times
How many proteins are there in an octamer?
Eight
What is the role of histone H1 in DNA packaging?
To attach one nucleosome to the next
What is the main difference in DNA packaging between prokaryotes and eukaryotes?
Prokaryotes use topoisomerases, while eukaryotes use histones and non-histone proteins
What is the correct name for the proteins that make up an octamer?
H2A, H2B, H3, H4
What is the role of topoisomerases in DNA packaging?
To introduce breaks in the DNA strands
What is the correct nomenclature for the base sugar with the phosphate in DNA?
Deoxyribose
What is the main advantage of DNA supercoiling in prokaryotes?
It allows for efficient DNA packaging
Which structure is responsible for condensing DNA into a solenoid?
Nucleosome
What is the role of histone h one in DNA packaging?
It keeps nucleosomes together
What is the main function of acetylating histones?
To open up DNA for transcription
What is the significance of the positive charge of nucleosomes in DNA packaging?
It pulls the DNA close
What is the function of scaffold proteins in DNA packaging?
To keep loops of solenoids together
How many kilo base pairs of DNA does each loop in the solenoid structure contain?
60 to 100 KB
What is the structure formed when loops of solenoids are organized in a flower-like manner?
Rosetta
Where are the two chromatids of a chromosome kept together?
Centromere
What is the p arm of a chromosome?
The short arm
What is the main difference in chromosome structure between eukaryotes and bacteria?
Eukaryotes have linear chromosomes, while bacteria have circular chromosomes
Which of the following is a correct statement about chromatids?
Chromatids are formed after replication and are attached to each other in the centromere.
What is the main function of introns in DNA?
Introns are non-coding parts of DNA that are removed from the RNA during splicing.
What is the relationship between genes and chromatids?
Genes are located on chromatids and lie next to each other.
What is the main function of exons in DNA?
Exons are parts of DNA that code for proteins.
What is the process by which introns are removed from RNA called?
Splicing
In the picture, are exons larger or smaller than introns?
Exons are larger than introns in the picture.
In real life, are exons larger or smaller than introns?
Introns are usually much bigger than exons in real life.
What is the main difference between the chromatids in the picture?
The chromatids in the picture are not identical because they contain different genes.
What is the main difference between the chromatids in real life?
The chromatids in real life are identical because they are formed from replication.
Which of the following is a correct statement about DNA packaging in real life?
Introns are usually much bigger than exons in DNA packaging.
Which structure is visible under the microscope when DNA is condensed during cell division?
Chromosomes
What is the purpose of condensing DNA during cell division?
To make it more visible under the microscope
Which part of the chromosome can be different in length between the P arm and the Q arm?
Chromatids
Where are the different alleles located within a chromosome?
On different chromatids
What can be exchanged during crossing over of chromosomes?
Information between chromosomes
Are chromosomes necessarily identical?
No
How many copies of chromosome one does an individual have?
Two
Where are the different alleles located within a chromosome?
On different chromatids
What is the process called when introns are removed from RNA?
Splicing
Are the two chromatids within one chromosome identical?
Yes
Which part of the nucleus is typically occupied by nontranscribed parts of the DNA?
The nuclear membrane
What is the behavior of mitochondrial DNA similar to?
Bacterial DNA
How many copies of DNA does each mitochondrion typically have?
Five to ten
What is the main function of mitochondria in a cell?
Energy production
How does DNA packaging differ between prokaryotes and eukaryotes?
Prokaryotes have circular DNA, while eukaryotes have linear DNA
Where are the nontranscribed parts of the DNA typically located within the nucleus?
The nuclear membrane
What is the structure of mitochondrial DNA?
Circular
What is the main difference between mitochondrial DNA and nuclear DNA?
Mitochondrial DNA is circular, while nuclear DNA is linear
Where are the transcribed parts of the DNA typically located within the nucleus?
The center
How does the behavior of mitochondrial DNA compare to bacterial DNA?
Mitochondrial DNA is circular, while bacterial DNA is linear
What is the total size of mitochondrial DNA?
17 kilobases
Which of the following is true about mitochondrial DNA coding?
It codes for rRNA, tRNAs, and some proteins
How does mitochondrial DNA compare to nuclear DNA in terms of size?
Mitochondrial DNA is much smaller than nuclear DNA
How many mitochondria can be found in a single cell?
A few hundred to several thousand up to 200,000
What is the main difference between nuclear DNA and mitochondrial DNA?
Nuclear DNA is predominantly coding DNA, while mitochondrial DNA has more non-coding DNA
What is the function of histone modifications?
To determine the structure of DNA
What happens when histones are acetylated?
Histones lose their positive charge and DNA becomes more open
Why can we only see chromosomes during cell division?
The DNA in interphase cells is not completely condensed
How many chromosomes do humans have?
46
What is the role of topoisomerases in DNA packaging?
To relieve supercoiling and prevent DNA tangling
Which enzyme is responsible for proofreading and cutting out wrongly attached bases during DNA replication?
Exonuclease
What is the function of the origin of replication in DNA replication?
To provide a starting point for the polymerase
What type of base sequence is easier to open up during DNA replication?
AT-rich sequence
What is the role of single strand binding proteins in DNA replication?
To stabilize single stranded DNA
Which enzyme is responsible for unzipping the DNA strands during DNA replication?
Helicase
What is the function of RNA primers in DNA replication?
To provide a free three prime site for DNA polymerase
What is the direction of DNA synthesis during DNA replication?
From five prime to three prime
What is the structure that forms when DNA strands are separated during DNA replication?
Fork
Which enzyme is responsible for elongating the DNA strands during DNA replication?
Polymerase
What is the function of the proofreading activity of DNA polymerase?
To cut out wrongly attached bases
Which of the following is the correct definition of a nucleotide?
A sugar and a base attached to each other
What is a nucleosome?
A combination of histones and DNA wrapped around it
When is DNA fully packed into chromosomes?
During the metaphase
What is the main purpose of transcription?
To make mRNA
When does replication of DNA occur?
During the interface phase
What happens to DNA during the metaphase of cell division?
It is fully packed into chromosomes
What is the process of DNA making up chromatids and then chromosomes called?
Condensation
What is the role of histones in DNA packaging?
To condense DNA into chromosomes
When is DNA fully accessible for transcription?
During the interface phase
What is the function of replication in DNA?
To create a copy of DNA
What is the main function of DNA polymerase during DNA replication?
To read the template strand from 5' to 3' and synthesize new DNA in the 3' to 5' direction
What is the difference between chromatin and nucleosome?
Chromatin refers to the whole structure of DNA combined with its proteins, while a nucleosome is a part of the chromatin
What is the correct direction of DNA synthesis during replication?
5' to 3'
What is the main difference between semiconservative and conservative DNA replication?
In semiconservative replication, each strand is the template for a new complementary strand, while in conservative replication, the original strands remain together and the new strands remain together
What is the role of DNA polymerase in DNA replication?
To synthesize new DNA strands by adding nucleotides in a complementary manner
What is the function of histone proteins in chromatin?
To help package and organize DNA into a compact structure
What is the correct direction of DNA synthesis during replication?
5' to 3'
What is the function of DNA polymerase in DNA replication?
To synthesize new DNA strands by adding nucleotides in a complementary manner
What is the difference between chromatin and nucleosome?
Chromatin refers to the whole structure of DNA combined with its proteins, while a nucleosome is a part of the chromatin
What is the main difference between semiconservative and conservative DNA replication?
In semiconservative replication, each strand is the template for a new complementary strand, while in conservative replication, the original strands remain together and the new strands remain together
Which enzyme attaches to the helicase during DNA replication in prokaryotes and is called a primo zone?
DNA primase
In which direction does the helicase move during DNA replication in the leading strand?
Left to right
Which enzyme synthesizes the DNA in the 5' to 3' direction during DNA replication?
DNA polymerase
In which direction does the polymerase move during DNA replication in the leading strand?
Left to right
In which direction does the helicase move during DNA replication in the lagging strand?
Left to right
In which direction does the polymerase move during DNA replication in the lagging strand?
Right to left
What is the term used to describe the combination of a short stretch of RNA with the DNA during DNA replication?
Okazaki fragment
Which DNA polymerase is responsible for removing the RNA primer and filling the gap?
Polymerase one
What is the name of the clamp that helps keep the DNA polymerase attached to the DNA?
PCNA
Which DNA polymerase is the major chromosome replicating enzyme?
Polymerase three
What is the enzyme responsible for closing the gaps between Okazaki fragments?
Ligase
Which DNA polymerase is involved in DNA repair?
Polymerase two
What is the activity of polymerase one that allows it to remove the RNA primer and DNA?
Exonuclease activity
What is the direction of replication that determines whether a strand is a leading or lagging strand?
Left to right
Which enzyme is responsible for removing the RNA primer and replacing it with DNA?
DNA polymerase one
What is the function of topoisomerases in DNA replication?
To remove positive supercoils
What is the role of the DNA ligase in DNA replication?
To join Okazaki fragments
What is the main difference between the leading and lagging strands in DNA replication?
The leading strand is synthesized continuously, while the lagging strand is synthesized discontinuously
What is the function of the helicase in DNA replication?
To unwind the DNA
What is the role of the primase in DNA replication?
To synthesize the RNA primer
What is the main difference between prokaryotic and eukaryotic DNA replication?
Prokaryotic DNA replication is unidirectional, while eukaryotic DNA replication is bidirectional
Which model describes the replication of nucleosomes in eukaryotes?
Semiconservative model
What happens to the nucleosome during replication in eukaryotes?
The nucleosome is split over two chromosomes
Which enzyme is responsible for removing the primer in eukaryotic DNA replication?
RNase
What is the function of single strand binding proteins in DNA replication?
To stabilize the single stranded DNA
Which protein acts as a sliding clamp in DNA replication?
PCNA
What is the main difference between DNA and RNA?
DNA has deoxyribose sugar while RNA has ribose sugar
Which type of RNA is involved in the regulation of gene expression?
miRNA
What is the role of DNA polymerase in DNA replication?
To synthesize new DNA strands
How many hydrogen bonds are formed between cytosine and guanine in DNA?
Two
Which nucleotides are used by the polymerase to build DNA during replication?
ATP, GTP, TTP, CTP
What is the function of an RNA primer in DNA replication?
To initiate DNA synthesis
What is the role of the Tata box in DNA replication?
To regulate transcription
Which polymerases are present in prokaryotes but not in eukaryotes?
Polymerase III and Polymerase I
What is the function of DNA primase?
To synthesize DNA primers
What is the main difference between DNA replication and transcription?
The direction of synthesis
Which type of RNA is involved in the assembly of ribosomes?
rRNA
What is the origin of replication in DNA replication?
The region where DNA unwinds
What is the function of histone proteins in chromatin?
To compact and organize DNA
What is the main difference between polymerase III and polymerase I?
Their function in DNA replication
Which one of the following statements about DNA replication is NOT true?
In eukaryotes, the DNA is located in the cytoplasm.
What is the main difference between the replication of DNA in prokaryotes and eukaryotes?
Prokaryotes have one type of polymerase while eukaryotes have multiple types.
Which of the following statements about mitochondrial DNA is true?
Mitochondrial DNA can undergo mutations.
What is the main factor that determines whether a woman has the same mitochondrial DNA as her great great great grandmother?
The transmission of mitochondrial DNA from mother to child.
Which of the following is NOT a potential cause of changes in DNA over time?
The number of replication falls.
What is the main difference between prokaryotes and eukaryotes in terms of DNA replication?
Prokaryotes have their DNA in the cytoplasm.
Which of the following is NOT a difference between prokaryotes and eukaryotes in terms of DNA replication?
Eukaryotes have more proteins involved in replication than prokaryotes.
Which of the following is NOT a potential cause of differences in mitochondrial DNA between individuals?
The number of replication falls in mitochondrial DNA.
What is the main difference between the replication of DNA in prokaryotes and eukaryotes in terms of origins of replication?
Prokaryotes have multiple origins of replication while eukaryotes have only one.
Which of the following is NOT a potential cause of changes in mitochondrial DNA over time?
The number of replication falls in mitochondrial DNA.
Which enzyme removes the RNA primers in prokaryotes during DNA replication?
DNA polymerase one
Which enzyme removes the RNA primers in eukaryotes during DNA replication?
RNase
Which type of topoisomerase is predominantly active in DNA unwinding?
Topoisomerase two
Is PCNA a type of single strand binding protein?
No
Why do we need Okazaki fragments during DNA replication?
To synthesize the lagging strand
Can DNA ligase and DNA polymerase one act while DNA is being synthesized?
Yes
Can DNA ligase and DNA polymerase one act while Okazaki fragments are being made?
Yes
Does DNA polymerase one remove the RNA primers during DNA replication?
Yes
Does DNA polymerase two remove the RNA primers during DNA replication?
No
Does DNA polymerase three remove the RNA primers during DNA replication?
No
What is the function of the okazaki fragments during DNA replication?
To provide a template for the synthesis of a new DNA strand
Which direction does the axonuclease work in?
Both 5' to 3' and 3' to 5'
What is the main function of the primosome complex on the lagging strand during DNA replication?
To synthesize RNA primers
Why does DNA shorten over time after multiple replications in somatic cells?
Due to the end replication problem
What is the function of telomerase in dealing with the end replication problem?
To lengthen telomeres at the ends of chromosomes
What is an okazaki fragment composed of?
RNA primer and DNA
What is the main difference in the number of replication forks between prokaryotes and eukaryotes?
Eukaryotes have more replication forks than prokaryotes
What is the main function of DNA primase during DNA replication?
To synthesize RNA primers
What is the direction of DNA synthesis during DNA replication?
5' to 3'
What is the main function of the exonuclease activity of DNA polymerase?
To proofread and correct errors in DNA synthesis
Which enzyme is responsible for synthesizing DNA during replication?
DNA polymerase three
Which nucleotide is used to pair with adenine (A) during DNA replication?
Thymine (T)
Which type of supercoiling occurs when a turn is added to the DNA?
Positive supercoil
What is the main function of DNA polymerase one during DNA replication?
Replacing the RNA primer with DNA
Where are ATP molecules synthesized during respiration?
Mitochondria
What is the role of topoisomerase two in DNA replication?
Making a double strand break and turning the DNA
Which type of supercoiling occurs when a turn is removed from the DNA?
Negative supercoil
Which nucleotide is used to pair with cytosine (C) during DNA replication?
Guanine (G)
Which enzyme is responsible for proofreading and cutting out wrongly attached bases during DNA replication?
DNA polymerase three
Where are the triphosphates used for DNA synthesis located?
Nucleus
What is the function of atelomerase in stem cells and germ cells?
To synthesize a long stretch of DNA
What is the function of the PCNA clamp in DNA replication?
To prevent the polymerase from falling off the DNA
Which type of DNA is primarily passed along the maternal line?
Mitochondrial DNA
Is it necessary to study DNA replication in both prokaryotes and eukaryotes?
Both prokaryotes and eukaryotes
What is the main difference between prokaryotic and eukaryotic polymerases?
Eukaryotic polymerases have different names
Is the lecture sufficient for understanding DNA replication?
No, extra research is required
Which form of supercoiling is more common in DNA?
Negative supercoiling
What is the function of non-coding DNA in eukaryotes?
To regulate gene expression
What is the main function of the exonuclease activity of DNA polymerase?
To remove RNA primers
Which enzyme removes the RNA primers in prokaryotes during DNA replication?
RNase H
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