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Which of the following steps in transcription is catalysed by RNA polymerase?
- a)Initiation
- b)Elongation
- c)Termination
- d)All of the above
Correct answer is option 'B'. Can you explain this answer?
Which of the following steps in transcription is catalysed by RNA polymerase?
a)
Initiation
b)
Elongation
c)
Termination
d)
All of the above
|
Anjali Iyer answered |
RNA polymerase moves along the template strand, synthesising an mRNA molecule. In prokaryotes RNA polymerase is a holoenzyme consisting of a number of subunits, including a sigma factor (transcription factor) that recognises the promoter. In eukaryotes there are three RNA polymerases: I, II and III. The process includes a proofreading mechanism.
The strand of DNA that forms mRNA is called?
- a)Lagging strand
- b)Coding strand
- c)Antisense strand
- d)Template strand
Correct answer is option 'D'. Can you explain this answer?
The strand of DNA that forms mRNA is called?
a)
Lagging strand
b)
Coding strand
c)
Antisense strand
d)
Template strand
|
Vijay Bansal answered |
The strand of DNA that forms mRNA is called the template strand or the antisense strand. During transcription, the DNA molecule unwinds, and one of the strands (the template strand) is used as a template to synthesize a complementary RNA molecule, which is called messenger RNA (mRNA). The other strand of DNA, which is not used as a template during transcription, is called the coding strand or the sense strand because it has the same sequence as the mRNA molecule (except for the presence of thymine instead of uracil).
Removal of the introns and joining of the exons in a defined order in a transcription unit is called- a)Capping
- b)Transformation
- c)Tailing
- d)Splicing
Correct answer is 'D'. Can you explain this answer?
Removal of the introns and joining of the exons in a defined order in a transcription unit is called
a)
Capping
b)
Transformation
c)
Tailing
d)
Splicing
|
Avantika Gupta answered |
Splicing is the process of removing introns and joining exons in a defined order in a transcription unit. This process takes place in the nucleus of eukaryotic cells and is mediated by a complex called the spliceosome.
Explanation:
• Transcription is the process of synthesizing RNA from a DNA template. During transcription, the entire DNA sequence is transcribed into RNA, including both the introns and exons.
• Introns are non-coding sequences within a gene, while exons are the coding sequences that specify the amino acid sequence of a protein. Introns need to be removed from the RNA sequence before translation can occur.
• Splicing is the process of removing introns and joining exons in a defined order, resulting in a mature messenger RNA (mRNA) molecule that can be translated into a protein.
• The splicing process is mediated by the spliceosome, a complex that consists of small nuclear RNAs (snRNAs) and proteins. The snRNAs base-pair with the intron sequences, while the proteins catalyze the chemical reactions that remove the introns and join the exons.
• Splicing is essential for the proper expression of genes, as it allows for the creation of multiple protein variants from a single gene by alternative splicing. Mutations that affect splicing can lead to a variety of diseases, including cancer and genetic disorders.
In conclusion, splicing is the process of removing introns and joining exons in a defined order in a transcription unit, and it is essential for the proper expression of genes.
Explanation:
• Transcription is the process of synthesizing RNA from a DNA template. During transcription, the entire DNA sequence is transcribed into RNA, including both the introns and exons.
• Introns are non-coding sequences within a gene, while exons are the coding sequences that specify the amino acid sequence of a protein. Introns need to be removed from the RNA sequence before translation can occur.
• Splicing is the process of removing introns and joining exons in a defined order, resulting in a mature messenger RNA (mRNA) molecule that can be translated into a protein.
• The splicing process is mediated by the spliceosome, a complex that consists of small nuclear RNAs (snRNAs) and proteins. The snRNAs base-pair with the intron sequences, while the proteins catalyze the chemical reactions that remove the introns and join the exons.
• Splicing is essential for the proper expression of genes, as it allows for the creation of multiple protein variants from a single gene by alternative splicing. Mutations that affect splicing can lead to a variety of diseases, including cancer and genetic disorders.
In conclusion, splicing is the process of removing introns and joining exons in a defined order in a transcription unit, and it is essential for the proper expression of genes.
DNA contains nucleobases, sugar and phosphate. Removal of which among these from a DNA sample will not significantly affect the length of DNA?- a)Nucleobases
- b)Sugar
- c)Phosphate
- d)None of the above
Correct answer is option 'A'. Can you explain this answer?
DNA contains nucleobases, sugar and phosphate. Removal of which among these from a DNA sample will not significantly affect the length of DNA?
a)
Nucleobases
b)
Sugar
c)
Phosphate
d)
None of the above
|
|
Shreya Singh answered |
Nucleobases, also known as nitrogenous bases are nitrogen-containing biological compounds that form nucleosides, which in turn are components of nucleotides, with all of these monomersconstituting the basic building blocks of nucleic acids. The ability of nucleobases to form base pairs and to stack one upon another leads directly to long-chain helical structures such as ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)....
The amino acid attaches to the tRNA at its- a)5′ end
- b)Anticodon site
- c)3′ end
- d)DHU loop
Correct answer is option 'C'. Can you explain this answer?
The amino acid attaches to the tRNA at its
a)
5′ end
b)
Anticodon site
c)
3′ end
d)
DHU loop
|
Rohit Shah answered |
TRNA with an attached amino acid is said to be "charged". The enzyme that attaches the amino acid to the 3'-OH is called an aminoacyl tRNA synthetase (aaRS). There is a specific tRNA for each amino acid, 20 in all. Similarly, there is a specific aaRS for each tRNA.
Protein synthesis occurs over- a)Cytoplasm
- b)Ribosomes
- c)Amino acids
- d)Mitochondria
Correct answer is option 'B'. Can you explain this answer?
Protein synthesis occurs over
a)
Cytoplasm
b)
Ribosomes
c)
Amino acids
d)
Mitochondria
|
Sathvika Tadri answered |
Ribosomes are site of protein synthesis and are known as protein factory
In E. coli, the lac operon gets switched on when- a)Lactose is present and it binds to the repressor
- b)RNA polymerase binds to the operator
- c)Lactose is present and it binds to RNA polymerase
- d)Repressor binds to operator
Correct answer is 'A'. Can you explain this answer?
In E. coli, the lac operon gets switched on when
a)
Lactose is present and it binds to the repressor
b)
RNA polymerase binds to the operator
c)
Lactose is present and it binds to RNA polymerase
d)
Repressor binds to operator
|
Geetika Shah answered |
In case of lactose presence
(i) Lactose acts as an inducer which binds to the repressor and forms an inactive repressor.
(ii) The repressor fails to bind to the operator region.
(iii) The RNA polymerase binds to the operator and transcript lac mRNA.
(iv) lac mRNA is polycistronic, i.e., produces all three enzymes, β -galactosidase, permeaseand transacetylase.
(v) The lac operon is switched on.
In case of lactose absence
(i) When lactose is absent, i gene regulates and produces repressor mRNA which translate repression.
(ii) The repressor protein binds to the operator region of the operon and as a resultprevents RNA polymerase to bind to the operon.
(iii) The operon is switched off.
In DNA replication, the leading strand replicates in the
- a)5′ → 3′ direction discontinuously
- b)5’→ 3′ direction continuously
- c)3′ → 5′ direction discontinuously
- d)3’→ 5′ direction continuously
Correct answer is option 'B'. Can you explain this answer?
In DNA replication, the leading strand replicates in the
a)
5′ → 3′ direction discontinuously
b)
5’→ 3′ direction continuously
c)
3′ → 5′ direction discontinuously
d)
3’→ 5′ direction continuously
|
|
Anjana Sharma answered |
The replication occurs in three steps in both prokaryotes and eukaryotes. These are include-
• Initiation
• Elongation
• Termination
The elongation steps involve the synthesis of leading and lagging strands.
The helicase and Dna B unzips the double-stranded DNA for replication, making a forked structure. The primase then performs the task of generating short strands of RNA that bind to the single-stranded DNA to initiate DNA synthesis with the help of DNA polymerase. This enzyme can work only in the 5′5′ to 3′3′ direction, the replication of the leading strand is done continuously whereas lagging-strand replication is discontinuous, with short Okazaki fragments being formed and later linked together.
So, the leading strand is the one that replicates in the 5′→3' direction continuously.
• Initiation
• Elongation
• Termination
The elongation steps involve the synthesis of leading and lagging strands.
The helicase and Dna B unzips the double-stranded DNA for replication, making a forked structure. The primase then performs the task of generating short strands of RNA that bind to the single-stranded DNA to initiate DNA synthesis with the help of DNA polymerase. This enzyme can work only in the 5′5′ to 3′3′ direction, the replication of the leading strand is done continuously whereas lagging-strand replication is discontinuous, with short Okazaki fragments being formed and later linked together.
So, the leading strand is the one that replicates in the 5′→3' direction continuously.
During transcription, the DNA site at which RNA polymerase binds is called- a)Enhancer
- b)Receptor
- c)Promoter
- d)Regulator
Correct answer is option 'C'. Can you explain this answer?
During transcription, the DNA site at which RNA polymerase binds is called
a)
Enhancer
b)
Receptor
c)
Promoter
d)
Regulator
|
|
Prashanth Chatterjee answered |
The site at which RNA polymerase binds during transcription is called the promoter. It is a specific region of DNA that is recognized by RNA polymerase, which then initiates the process of transcription. The promoter is located upstream of the transcriptional start site and contains specific DNA sequences that are recognized by RNA polymerase and other transcription factors.
The promoter plays a crucial role in regulating gene expression, as different promoters can activate or repress transcription depending on the cellular context. The strength of the promoter can also affect the rate of transcription, with stronger promoters resulting in higher levels of mRNA production.
There are different types of promoters, including constitutive promoters, which are active in all cells, and inducible promoters, which are activated in response to specific signals or conditions. The sequence and structure of the promoter can vary depending on the gene being transcribed and the organism in which it is expressed.
In summary, the promoter is a critical element in the process of transcription, serving as the site at which RNA polymerase binds and initiating the production of mRNA from DNA. It plays a crucial role in regulating gene expression and can vary in strength and specificity depending on the cellular context and the gene being transcribed.
The promoter plays a crucial role in regulating gene expression, as different promoters can activate or repress transcription depending on the cellular context. The strength of the promoter can also affect the rate of transcription, with stronger promoters resulting in higher levels of mRNA production.
There are different types of promoters, including constitutive promoters, which are active in all cells, and inducible promoters, which are activated in response to specific signals or conditions. The sequence and structure of the promoter can vary depending on the gene being transcribed and the organism in which it is expressed.
In summary, the promoter is a critical element in the process of transcription, serving as the site at which RNA polymerase binds and initiating the production of mRNA from DNA. It plays a crucial role in regulating gene expression and can vary in strength and specificity depending on the cellular context and the gene being transcribed.
Which of the following are not the components of RNA?- a)Thymine
- b)Adenine
- c)Guanine
- d)Cytosine
Correct answer is option 'A'. Can you explain this answer?
Which of the following are not the components of RNA?
a)
Thymine
b)
Adenine
c)
Guanine
d)
Cytosine
|
Ishani Nambiar answered |
Thymine is present in DNA but not in RNA.
The portion of DNA which contains information for an entire polypeptide is called- a)Operon
- b)Recon
- c)Muton
- d)Cistron
Correct answer is option 'D'. Can you explain this answer?
The portion of DNA which contains information for an entire polypeptide is called
a)
Operon
b)
Recon
c)
Muton
d)
Cistron
|
Nikita Singh answered |
Cistron is a nucleotide sequence responsible for the synthesis of a polypeptide sequence of a functional protein.
The word cistron is used to emphasize that genes exhibit a specific behavior in a cis-trans test, distinct positions (or loci) within a genome are cistronic.
Repressor proteins are coded for by ______ genes.- a)Promoter
- b)Structural
- c)Regulator
- d)Operator
Correct answer is option 'C'. Can you explain this answer?
Repressor proteins are coded for by ______ genes.
a)
Promoter
b)
Structural
c)
Regulator
d)
Operator
|
|
Gaurav Kumar answered |
Regulator genes codes for repressor proteins during translation of DNA into protein via mRNA.
Identify the purine base of nucleic acids in the following- a)Cytosine
- b)Thymine
- c)Uracil
- d)Adenine
Correct answer is option 'D'. Can you explain this answer?
Identify the purine base of nucleic acids in the following
a)
Cytosine
b)
Thymine
c)
Uracil
d)
Adenine
|
Soumya Ahuja answered |
Purines have two rings in their structure, but pyrimidine bases have only one ring.Adenine has two rings in its structure.
The coding segment of DNA isa)Mutonb)Repliconc)Intrond)CodonCorrect answer is option 'D'. Can you explain this answer?
|
|
Anjali Iyer answered |
Exon: The coding sequences or expressed sequences are defined as exon. Exons are said to be those sequences that appear in mature or processed RNA.
Out of 64 codons, the number of codons with GGG is- a)4
- b)1
- c)2
- d)6
Correct answer is option 'B'. Can you explain this answer?
Out of 64 codons, the number of codons with GGG is
a)
4
b)
1
c)
2
d)
6
|
|
Sankar Banerjee answered |
GGG code is present only 1 tym nd the amino acid produced by GGG is glycine.
Some amino acids are coded by more than one codon; hence, the code is- a)Unambiguous
- b)Universal
- c)Degenerate
- d)Initiator
Correct answer is option 'C'. Can you explain this answer?
Some amino acids are coded by more than one codon; hence, the code is
a)
Unambiguous
b)
Universal
c)
Degenerate
d)
Initiator
|
|
Anjali Iyer answered |
The genetic code is degenerate: Some amino acids are encoded by more than one codon, inasmuch as there are 64 possible base triplets and only 20 amino acids. In fact, 61 of the 64 possible triplets specify particular amino acids and 3 triplets (called stop codons) designate the termination of translation. Thus, for most amino acids, there is more than one code word.
DNA has genetic properties was revealed for the first time by- a)Chargaff
- b)Griffith
- c)Avery
- d)Wilkins
Correct answer is option 'C'. Can you explain this answer?
DNA has genetic properties was revealed for the first time by
a)
Chargaff
b)
Griffith
c)
Avery
d)
Wilkins
|
|
Pooja Choudhury answered |
The discovery that DNA has genetic properties was first revealed by Oswald Avery and his team of scientists in 1944. Avery was a molecular biologist who worked at the Rockefeller Institute for Medical Research in New York City.
Experiment
Avery and his team conducted a series of experiments to determine whether DNA was the genetic material responsible for the transformation of bacteria. They used two strains of Streptococcus pneumoniae, one that was virulent (able to cause disease) and one that was non-virulent. The virulent strain had a capsule made of a complex sugar that protected it from the immune system, while the non-virulent strain lacked this capsule and was easily destroyed by the immune system.
Results
Avery and his team extracted various biochemical components from the virulent strain of bacteria, including proteins, lipids, RNA, and DNA. They then mixed each of these components with the non-virulent strain to see if they could induce transformation. Only the DNA extract was able to transform the non-virulent strain into a virulent one, proving that DNA was the genetic material responsible for the transformation.
Conclusion
Avery's discovery was groundbreaking because it showed that DNA, which was previously thought to be a simple molecule with no biological significance, was in fact the carrier of genetic information. This discovery paved the way for the development of the field of molecular biology and our current understanding of genetics.
Experiment
Avery and his team conducted a series of experiments to determine whether DNA was the genetic material responsible for the transformation of bacteria. They used two strains of Streptococcus pneumoniae, one that was virulent (able to cause disease) and one that was non-virulent. The virulent strain had a capsule made of a complex sugar that protected it from the immune system, while the non-virulent strain lacked this capsule and was easily destroyed by the immune system.
Results
Avery and his team extracted various biochemical components from the virulent strain of bacteria, including proteins, lipids, RNA, and DNA. They then mixed each of these components with the non-virulent strain to see if they could induce transformation. Only the DNA extract was able to transform the non-virulent strain into a virulent one, proving that DNA was the genetic material responsible for the transformation.
Conclusion
Avery's discovery was groundbreaking because it showed that DNA, which was previously thought to be a simple molecule with no biological significance, was in fact the carrier of genetic information. This discovery paved the way for the development of the field of molecular biology and our current understanding of genetics.
Which particular process was used by Meselson and Stahl in order to study the semi-conservative replication of DNA?
- a)Density gradient centrifugation
- b)Chromatography
- c)Centrifugation
- d)Buoyant density centrifugation
Correct answer is option 'A'. Can you explain this answer?
Which particular process was used by Meselson and Stahl in order to study the semi-conservative replication of DNA?
a)
Density gradient centrifugation
b)
Chromatography
c)
Centrifugation
d)
Buoyant density centrifugation
|
|
Sahil Basu answered |
Density Gradient Centrifugation
Meselson and Franklin used density gradient centrifugation to study the semi-conservative replication of DNA. This technique is based on the principle that molecules of different densities will settle at different positions in a gradient when subjected to centrifugal force.
Steps Involved in the Process
1. Growing bacteria in a medium containing a heavy isotope of nitrogen
The experiment involved growing E. coli bacteria in a medium containing a heavy isotope of nitrogen, 15N, for many generations. This resulted in all the bacterial DNA being labeled with 15N.
2. Transferring bacteria to a medium containing a lighter isotope of nitrogen
Next, the bacteria were transferred to a medium containing a lighter isotope of nitrogen, 14N, and allowed to grow for one generation.
3. Isolation of DNA
The bacterial cells were then harvested and their DNA was extracted.
4. Density gradient centrifugation
The DNA samples were subjected to density gradient centrifugation, which involved placing the DNA in a tube containing a gradient of cesium chloride. The tube was then spun at high speeds in a centrifuge, causing the DNA molecules to migrate to the position in the gradient that corresponded to their buoyant density.
5. Observations
The resulting DNA bands were observed under ultraviolet light. If DNA replication was conservative, the DNA band would have been a single band of intermediate density, whereas if it was semi-conservative, two bands would have been observed, one of intermediate density and one of lighter density.
6. Conclusion
Meselson and Franklin observed that the DNA bands were indeed two distinct bands, one of intermediate density and one of lighter density. This provided evidence for the semi-conservative replication of DNA.
Conclusion
Density gradient centrifugation was a crucial technique used by Meselson and Franklin to study the semi-conservative replication of DNA. This technique allowed them to separate the newly synthesized DNA from the parental DNA and provided evidence for the semi-conservative mode of DNA replication.
Meselson and Franklin used density gradient centrifugation to study the semi-conservative replication of DNA. This technique is based on the principle that molecules of different densities will settle at different positions in a gradient when subjected to centrifugal force.
Steps Involved in the Process
1. Growing bacteria in a medium containing a heavy isotope of nitrogen
The experiment involved growing E. coli bacteria in a medium containing a heavy isotope of nitrogen, 15N, for many generations. This resulted in all the bacterial DNA being labeled with 15N.
2. Transferring bacteria to a medium containing a lighter isotope of nitrogen
Next, the bacteria were transferred to a medium containing a lighter isotope of nitrogen, 14N, and allowed to grow for one generation.
3. Isolation of DNA
The bacterial cells were then harvested and their DNA was extracted.
4. Density gradient centrifugation
The DNA samples were subjected to density gradient centrifugation, which involved placing the DNA in a tube containing a gradient of cesium chloride. The tube was then spun at high speeds in a centrifuge, causing the DNA molecules to migrate to the position in the gradient that corresponded to their buoyant density.
5. Observations
The resulting DNA bands were observed under ultraviolet light. If DNA replication was conservative, the DNA band would have been a single band of intermediate density, whereas if it was semi-conservative, two bands would have been observed, one of intermediate density and one of lighter density.
6. Conclusion
Meselson and Franklin observed that the DNA bands were indeed two distinct bands, one of intermediate density and one of lighter density. This provided evidence for the semi-conservative replication of DNA.
Conclusion
Density gradient centrifugation was a crucial technique used by Meselson and Franklin to study the semi-conservative replication of DNA. This technique allowed them to separate the newly synthesized DNA from the parental DNA and provided evidence for the semi-conservative mode of DNA replication.
Why are UGA, UAG and UAA called termination codons?- a)They terminate anticodons
- b)They are presenting at the beginning of mRNA
- c)They indicate initiation of translation
- d)They do not specify any amino acid
Correct answer is option 'D'. Can you explain this answer?
Why are UGA, UAG and UAA called termination codons?
a)
They terminate anticodons
b)
They are presenting at the beginning of mRNA
c)
They indicate initiation of translation
d)
They do not specify any amino acid
|
|
Supriya Senapati answered |
Since The stop codons are UAA, UAG, and UGA. They encode no amino acid. The ribosome pauses and falls off the mRNA.
According to Chargaff’s rule, which one is correct?- a)[A] + [T] = [G] + [C]
- b)[A] + [C] = [G] + [T]
- c)[A] + [G] = [T] + [C]
- d)All of these
Correct answer is option 'C'. Can you explain this answer?
According to Chargaff’s rule, which one is correct?
a)
[A] + [T] = [G] + [C]
b)
[A] + [C] = [G] + [T]
c)
[A] + [G] = [T] + [C]
d)
All of these
|
|
Geetika Shah answered |
According to Chargaff’s rule in all cellular DNA, regardless of the species, number of adenosine residues is equal to the number of thymidine residues which means that A = T and the number of guanosine residues is equal to the number of cytidine residues; G = C . Hence, that the sum of the purine residues equals the sum of the pyrimidine residues; i.e., A + G = T + C.
Which of the following is true about phosphodiester linkage?- a)5’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide
- b)3’-phosphate group of one nucleotide unit is joined to the 5’-hydroxyl group of the next nucleotide
- c)5’-phosphate group of one nucleotide unit is joined to the 5’-hydroxyl group of the next nucleotide
- d)3’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide
Correct answer is option 'A'. Can you explain this answer?
Which of the following is true about phosphodiester linkage?
a)
5’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide
b)
3’-phosphate group of one nucleotide unit is joined to the 5’-hydroxyl group of the next nucleotide
c)
5’-phosphate group of one nucleotide unit is joined to the 5’-hydroxyl group of the next nucleotide
d)
3’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide
|
Vaibhav Basu answered |
5’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide.
Which chromosome of human genome contains least number of genes?- a)Chromosome 12
- b)Chromosome X
- c)Chromosome Y
- d)Chromosome 1
Correct answer is option 'C'. Can you explain this answer?
Which chromosome of human genome contains least number of genes?
a)
Chromosome 12
b)
Chromosome X
c)
Chromosome Y
d)
Chromosome 1
|
|
Afifa Aaliya answered |
Chromosomes are thread like structures of DNA and proteins that carry genetic information of organisms in the form of genes. The human chromosomes with least number of genes is Your chromosome.
Option " C " is correct answer.
Option " C " is correct answer.
DNA is made of two chains that twist about one another in the shape of a _______.- a)Broken ladder
- b)Straight ladder
- c)Straight spiral
- d)Double helix
Correct answer is option 'D'. Can you explain this answer?
DNA is made of two chains that twist about one another in the shape of a _______.
a)
Broken ladder
b)
Straight ladder
c)
Straight spiral
d)
Double helix
|
|
Ananya Duney answered |
They are twist in a right handed double helical way therefore it's called double helix DNA which was given by Watson and crick
"hope it'll help"
"hope it'll help"
Whose experiments cracked the DNA and discovered unequivocally that a genetic code is a triplet?- a)Nirenberg and Matthaei
- b)Hershey and Chase
- c)Beadle and Tatum
- d)Morgan and Sturtevant
Correct answer is option 'A'. Can you explain this answer?
Whose experiments cracked the DNA and discovered unequivocally that a genetic code is a triplet?
a)
Nirenberg and Matthaei
b)
Hershey and Chase
c)
Beadle and Tatum
d)
Morgan and Sturtevant
|
|
Rajat Kapoor answered |
The existence of a triplet code was simply an assumption till 1961 when Nirenberg and Methaei proved its existence by experiment. They were able to synthesise artificial mRNA, which contained only one nitrogenous base, ie, uracil. This synthetic poly-U sequence was then placed in a cell-free system containing protein synthesizing enzymes (extracted from bacterium E. coil) and 20 amino acids together with necessary ATP. During the process, a small polypeptide molecule was produced, which was formed by the linking of phenylalanine. This issuggested that UUU is code for phenylalanine. Nirenberg got Nobel Prize for his contributions.
Codon is made up of- a)Single nucleotide
- b)Four nucleotides
- c)three nucleotides
- d)two nucleotides
Correct answer is option 'C'. Can you explain this answer?
Codon is made up of
a)
Single nucleotide
b)
Four nucleotides
c)
three nucleotides
d)
two nucleotides
|
|
Gopikas S answered |
Codons are found in mRNA.A sequence of three nucleotides in messenger RNA makes a codon for an amino acid. A codon is a sequence of three adjacent nucleotides constituting the genetic code that determines the insertion of a specific amino acid in a polypeptide chain during protein synthesis or the signal to stop protein synthesis. A codon is defined by the initial nucleotide from which translation starts.
Building blocks of nucleic acids are- a)Nucleotides
- b)Nucleosides
- c)Amino acids
- d)Histones
Correct answer is option 'A'. Can you explain this answer?
Building blocks of nucleic acids are
a)
Nucleotides
b)
Nucleosides
c)
Amino acids
d)
Histones
|
Pankaj Kulkarni answered |
Nucleotides are the building blocks of nucleic acids.
Which of the following is True about purine and pyrimidine bases?
- a)They are hydrophobic and relatively insoluble in water at the near-neutral pH of the cell
- b)At acidic or alkaline pH the bases become charged and their solubility in water decreases
- c)Purines have two rings in their structure, but pyrimidine bases have only one ring
- d)At acidic or alkaline pH the bases become charged and their solubility in water increases
Correct answer is option 'A,C,D'. Can you explain this answer?
Which of the following is True about purine and pyrimidine bases?
a)
They are hydrophobic and relatively insoluble in water at the near-neutral pH of the cell
b)
At acidic or alkaline pH the bases become charged and their solubility in water decreases
c)
Purines have two rings in their structure, but pyrimidine bases have only one ring
d)
At acidic or alkaline pH the bases become charged and their solubility in water increases
|
|
Mohit Nair answered |
The purine and pyrimidine bases are hydrophobic and relatively insoluble in water at the near-neutral pH of the cell. At acidic or alkaline pH the bases become charged and their solubility in water increases.
What is the composition of nucleoside?- a)a sugar + a phosphate
- b)a base + a sugar
- c)a base + a phosphate
- d)a base + a sugar + phosphate
Correct answer is option 'B'. Can you explain this answer?
What is the composition of nucleoside?
a)
a sugar + a phosphate
b)
a base + a sugar
c)
a base + a phosphate
d)
a base + a sugar + phosphate
|
|
Pankaj Kulkarni answered |
A nucleoside is composed of a base and a sugar.
The following code codes for which of the amino acid respectively?
AUG and GUG- a)Phenylalanine, tyrosine
- b)Methionine, valine
- c)Methionine, alanine
- d)Lysine, valine
Correct answer is option 'B'. Can you explain this answer?
The following code codes for which of the amino acid respectively?
AUG and GUG
AUG and GUG
a)
Phenylalanine, tyrosine
b)
Methionine, valine
c)
Methionine, alanine
d)
Lysine, valine
|
|
Riya Banerjee answered |
Three base triplets form a codon that codes for an amino acid. Thus AUG codes for methionine and GUG codes for Valine. AUG and GUG are both initiating codons for translation.
The code AUG stands for- a)Aniline
- b)Methionine
- c)Glycine
- d)N-formyl methionine
Correct answer is option 'B'. Can you explain this answer?
The code AUG stands for
a)
Aniline
b)
Methionine
c)
Glycine
d)
N-formyl methionine
|
|
Vijay Bansal answered |
The genetic code consists of 64 triplets of nucleotides. These triplets are called codons.With three exceptions, each codon encodes for one of the 20 amino acids used in the synthesis of proteins. That produces some redundancy in the code: most of the amino acids being encoded by more than one codon.
One codon, AUG serves two related functions:
1. it signals the start of translation
2. it codes for the incorporation of the amino acid methionine (Met) into the growing polypeptide chain
What is called Griffith effect?- a)DNA transcription
- b)RNA translation
- c)Bacterial transduction
- d)Bacterial transformation
Correct answer is option 'D'. Can you explain this answer?
What is called Griffith effect?
a)
DNA transcription
b)
RNA translation
c)
Bacterial transduction
d)
Bacterial transformation
|
|
Mathi Mathi answered |
Bacteria can take up forigen DNA in a process called transformation. It occurs after restriction digest and ligation and transfers newly made plasmid to bacteria.
Bacteria with a plasmid are antibiotic resistant, and each will form a colony.
Bacteria with a plasmid are antibiotic resistant, and each will form a colony.
That the mode of DNA replication is semiconservative was demonstrated by- a)Khorana
- b)Meselson and Stahl
- c)Taylor
- d)Watson and Crick
Correct answer is option 'B'. Can you explain this answer?
That the mode of DNA replication is semiconservative was demonstrated by
a)
Khorana
b)
Meselson and Stahl
c)
Taylor
d)
Watson and Crick
|
|
Rajat Kapoor answered |
Meselson and stahl (1958) cultured E. coli bacteria in a culture medium to prove that DNA replication is semi conservative.
By which bonds the purine & pyrimidine pairs of Complementary Strands of DNA held together?- a)N – bonds
- b)H – bonds
- c)O - bonds
- d)C - bonds
Correct answer is option 'B'. Can you explain this answer?
By which bonds the purine & pyrimidine pairs of Complementary Strands of DNA held together?
a)
N – bonds
b)
H – bonds
c)
O - bonds
d)
C - bonds
|
|
Swati Verma answered |
In complementary strands of DNA, purines and pyrimidine are held together by Hydrogen bond (H-bond). Adenine and Thymine have double hydrogen bond and cytosine and guanine are held by triple hydrogen bond.
RNA polymerase is only capable of catalyzing the process of- a)Elongation
- b)Initiation
- c)Termination
- d)All of the above
Correct answer is option 'A'. Can you explain this answer?
RNA polymerase is only capable of catalyzing the process of
a)
Elongation
b)
Initiation
c)
Termination
d)
All of the above
|
Arnav Iyer answered |
During protein synthesis, elongation of peptide chain is catalyzed by the enzyme RNA polymerase. Elongation continuous until a non-sense or stop codon is reached.
Who among the following scientists had no contribution in the development of the double helix model for the structure of DNA?- a)Meselson and Stahl
- b)Rosalind Franklin
- c)Erwin Chargaff
- d)Maurice Wilkins
Correct answer is option 'A'. Can you explain this answer?
Who among the following scientists had no contribution in the development of the double helix model for the structure of DNA?
a)
Meselson and Stahl
b)
Rosalind Franklin
c)
Erwin Chargaff
d)
Maurice Wilkins
|
Dilip Chaurasiya answered |
Meselson and Stahl prove experimentally semi conservation of DNA replication not say but structure of DNA.
PCR and restriction fragment length polymorphism are methods for- a)Genetic fingerprinting
- b)Genetic transformation
- c)DNA sequencing
- d)Study of enzymes
Correct answer is option 'A'. Can you explain this answer?
PCR and restriction fragment length polymorphism are methods for
a)
Genetic fingerprinting
b)
Genetic transformation
c)
DNA sequencing
d)
Study of enzymes
|
|
Janhavi Menon answered |
Genetic Fingerprinting
Genetic fingerprinting or DNA fingerprinting is a technique used to identify individuals based on their unique DNA profiles. PCR and Restriction Fragment Length Polymorphism (RFLP) are two commonly used methods for genetic fingerprinting.
Polymerase Chain Reaction (PCR)
PCR is a powerful technique used to amplify a specific DNA sequence. It involves a series of repeated cycles of denaturation, annealing, and extension, resulting in the exponential amplification of a specific DNA fragment. PCR is used in genetic fingerprinting to amplify DNA from a sample, such as blood or tissue, and create multiple copies of a specific DNA fragment for analysis.
Restriction Fragment Length Polymorphism (RFLP)
RFLP is a technique used to identify variations in DNA sequences between individuals. It involves the use of restriction enzymes to cut DNA at specific sites, resulting in fragments of different sizes. The resulting fragments are separated by gel electrophoresis and visualized using a staining agent. The pattern of fragment sizes is unique to each individual and can be used to identify them.
Applications of Genetic Fingerprinting
Genetic fingerprinting has a wide range of applications, including:
- Forensic investigations: DNA evidence can be used to identify suspects or victims in criminal investigations.
- Paternity testing: DNA analysis can be used to determine biological relationships, such as paternity or maternity.
- Medical diagnosis: Genetic fingerprinting can be used to diagnose genetic diseases and identify carriers of genetic mutations.
- Evolutionary studies: Genetic fingerprinting can be used to study the evolutionary relationships between different species.
Conclusion
PCR and RFLP are two powerful techniques used in genetic fingerprinting. These techniques have revolutionized the field of forensic science and have a wide range of applications in medicine, biology, and genetics.
Genetic fingerprinting or DNA fingerprinting is a technique used to identify individuals based on their unique DNA profiles. PCR and Restriction Fragment Length Polymorphism (RFLP) are two commonly used methods for genetic fingerprinting.
Polymerase Chain Reaction (PCR)
PCR is a powerful technique used to amplify a specific DNA sequence. It involves a series of repeated cycles of denaturation, annealing, and extension, resulting in the exponential amplification of a specific DNA fragment. PCR is used in genetic fingerprinting to amplify DNA from a sample, such as blood or tissue, and create multiple copies of a specific DNA fragment for analysis.
Restriction Fragment Length Polymorphism (RFLP)
RFLP is a technique used to identify variations in DNA sequences between individuals. It involves the use of restriction enzymes to cut DNA at specific sites, resulting in fragments of different sizes. The resulting fragments are separated by gel electrophoresis and visualized using a staining agent. The pattern of fragment sizes is unique to each individual and can be used to identify them.
Applications of Genetic Fingerprinting
Genetic fingerprinting has a wide range of applications, including:
- Forensic investigations: DNA evidence can be used to identify suspects or victims in criminal investigations.
- Paternity testing: DNA analysis can be used to determine biological relationships, such as paternity or maternity.
- Medical diagnosis: Genetic fingerprinting can be used to diagnose genetic diseases and identify carriers of genetic mutations.
- Evolutionary studies: Genetic fingerprinting can be used to study the evolutionary relationships between different species.
Conclusion
PCR and RFLP are two powerful techniques used in genetic fingerprinting. These techniques have revolutionized the field of forensic science and have a wide range of applications in medicine, biology, and genetics.
During splicing, the exons are joined and the enzyme which catalyses this reaction is- a)RNA ligase
- b)RNA polymerase
- c)RNA catalase
- d)RNA permease
Correct answer is option 'A'. Can you explain this answer?
During splicing, the exons are joined and the enzyme which catalyses this reaction is
a)
RNA ligase
b)
RNA polymerase
c)
RNA catalase
d)
RNA permease
|
Ved Patidar answered |
Joint joining of nucleotide in RNA and DNA is done by DNA/RNA ligase.
Genetic information is carried out by long chain molecule made up of- a)Nucleotides
- b)Enzymes
- c)Histone proteins
- d)Amino acids
Correct answer is option 'A'. Can you explain this answer?
Genetic information is carried out by long chain molecule made up of
a)
Nucleotides
b)
Enzymes
c)
Histone proteins
d)
Amino acids
|
|
Aarya Khanna answered |
Genetic information is carried out by DNA and RNA. Both DNA and RNA are called genetic material, made up of long chain of nucleotide having-nitrogenous base, sugar and phosphate ions.
The hybridization of probes having radioactive isotopes with various sequence of nitrogen bases with ssVNTR is called?- a)Eastern blotting
- b)Southern blotting
- c)Western blotting
- d)Northern blotting
Correct answer is option 'B'. Can you explain this answer?
The hybridization of probes having radioactive isotopes with various sequence of nitrogen bases with ssVNTR is called?
a)
Eastern blotting
b)
Southern blotting
c)
Western blotting
d)
Northern blotting
|
|
Ankita Raj answered |
The hybridization of probes having radioactive isotopes with various sequence of nitrogen bases with ssVNTR is called southern blotting. Southern blotting is a laboratory technique used to detect a specific DNA sequence in a blood or tissue sample. A restriction enzyme is used to cut a sample of DNA into fragments that are separated using gel electrophoresis. The DNA fragments are transferred out of the gel to the surface of a membrane. The membrane is exposed to a DNA probe labeled with a radioactive or chemical tag. If the probe binds to the membrane, then the probe sequence is present in the sample. Hence, the correct answer is option 'B'.
A typical nucleosome contains- a)100 bp of DNA helix
- b)400 bp of DNA helix
- c)200 bp of DNA helix
- d)300 bp of DNA helix
Correct answer is option 'C'. Can you explain this answer?
A typical nucleosome contains
a)
100 bp of DNA helix
b)
400 bp of DNA helix
c)
200 bp of DNA helix
d)
300 bp of DNA helix
|
|
Suresh Kumar answered |
A typical nucleosome contains 200 bp of DNA double helix wrapped(2 turns) around a core of histone octamer having two copies of each of four types of histone proteins ..H2A,H2B,H3,&H4.....H1 histone molecule lies outside the nucleosome core & seals the two turns of DNA by binding at the point where DNA enters and leaves the core..
Group of adjacent nucleotides are joined by- a)Phosphodiester bond
- b)Peptide bond
- c)Ionic bond
- d)Covalent bond
Correct answer is option 'A'. Can you explain this answer?
Group of adjacent nucleotides are joined by
a)
Phosphodiester bond
b)
Peptide bond
c)
Ionic bond
d)
Covalent bond
|
|
Soumya Ahuja answered |
The phosphodiester linkage joins 3’ carbon atom of one sugar molecule and 5’ carbon atom of another carbon atom.
Hargobind Khorana is known for his experiments based on which of the following?
- a)Synthesis of protein
- b)Discovery of DNA structure
- c)Discovery of tRNA
- d)Discovery of DNA ligase enzyme
Correct answer is option 'D'. Can you explain this answer?
Hargobind Khorana is known for his experiments based on which of the following?
a)
Synthesis of protein
b)
Discovery of DNA structure
c)
Discovery of tRNA
d)
Discovery of DNA ligase enzyme
|
Tarun Kulkarni answered |
Hargobind Khorana: Discoverer of DNA Ligase Enzyme
Introduction:
Hargobind Khorana was an Indian-American biochemist who received the Nobel Prize in Physiology or Medicine in 1968 for his contribution to the deciphering of the genetic code.
Discovery of DNA Ligase Enzyme:
Khorana's research on nucleic acids led him to discover the DNA ligase enzyme. In 1967, he and his team were able to synthesize the first wholly artificial gene, using the enzyme DNA ligase to link together 77 nucleotides in the correct sequence.
Significance of Discovery:
The discovery of the DNA ligase enzyme was a significant contribution to the field of genetics. The enzyme plays a crucial role in the replication and repair of DNA by joining together the ends of DNA strands, allowing for the formation of a continuous strand. This discovery has led to advancements in genetic engineering, gene therapy, and the development of new drugs.
Conclusion:
Khorana's discovery of the DNA ligase enzyme was a significant contribution to the field of genetics and has led to advancements in various areas of science. His research and discoveries have paved the way for further exploration in the field of genetics and have had a profound impact on the world of science and medicine.
Introduction:
Hargobind Khorana was an Indian-American biochemist who received the Nobel Prize in Physiology or Medicine in 1968 for his contribution to the deciphering of the genetic code.
Discovery of DNA Ligase Enzyme:
Khorana's research on nucleic acids led him to discover the DNA ligase enzyme. In 1967, he and his team were able to synthesize the first wholly artificial gene, using the enzyme DNA ligase to link together 77 nucleotides in the correct sequence.
Significance of Discovery:
The discovery of the DNA ligase enzyme was a significant contribution to the field of genetics. The enzyme plays a crucial role in the replication and repair of DNA by joining together the ends of DNA strands, allowing for the formation of a continuous strand. This discovery has led to advancements in genetic engineering, gene therapy, and the development of new drugs.
Conclusion:
Khorana's discovery of the DNA ligase enzyme was a significant contribution to the field of genetics and has led to advancements in various areas of science. His research and discoveries have paved the way for further exploration in the field of genetics and have had a profound impact on the world of science and medicine.
Can you explain the answer of this question below:Repressor protein is produced by
- A:
Operator gene
- B:
Promotor gene
- C:
Structural gene
- D:
Regulator gene
The answer is d.
Repressor protein is produced by
Operator gene
Promotor gene
Structural gene
Regulator gene
|
|
Rajat Kapoor answered |
In prokaryotes, regulator genes often code for repressor proteins. Repressor proteins bind to operators or promoters, preventing RNA polymerase from transcribing RNA. They are usually constantly expressed so the cell always has a supply of repressor molecules on hand.
DNA polymerases are generally used in DNA replication- a)For adding carbonyl compound
- b)For proofreading
- c)For breaking and joining pieces of one DNA strand
- d)To cut the helix at certain places
Correct answer is option 'B'. Can you explain this answer?
DNA polymerases are generally used in DNA replication
a)
For adding carbonyl compound
b)
For proofreading
c)
For breaking and joining pieces of one DNA strand
d)
To cut the helix at certain places
|
|
Vijay Bansal answered |
Thermo Scientific Phusion High-Fidelity DNA Polymerase was created by fusing a dsDNA-binding domain to a Pyrococcus-like proofreading polymerase. Due to this unique fusion technique, Phusion DNA Polymerases have extremely low error rates and are considered a gold standard for high-fidelity PCR.
Which of the following statements is true?
- a)Sugar component of a nucleotide is ribose
- b)Sugar component of a nucleotide is deoxyribose
- c)The bases in nucleotides are attached to a pentose sugar moiety by a glycosidic linkage
- d)The sugar molecule of the nucleotide is in L-configuration
Correct answer is option 'C'. Can you explain this answer?
Which of the following statements is true?
a)
Sugar component of a nucleotide is ribose
b)
Sugar component of a nucleotide is deoxyribose
c)
The bases in nucleotides are attached to a pentose sugar moiety by a glycosidic linkage
d)
The sugar molecule of the nucleotide is in L-configuration
|
Snehal Shah answered |
Option A: Sugar component of a nucleotide is ribose. This statement is true for RNA nucleotides. However, for DNA, the sugar is deoxyribose, not ribose.
Option B: Sugar component of a nucleotide is deoxyribose. This statement is true for DNA nucleotides, but not for RNA nucleotides.
Option C: The bases in nucleotides are attached to a pentose sugar moiety by a glycosidic linkage. This statement is universally true for all nucleotides, whether in DNA or RNA. The nitrogenous base is attached to the sugar molecule via a glycosidic bond.
Option D: The sugar molecule of the nucleotide is in L-configuration. This statement is false. The sugar in nucleotides is in the D-configuration.
The correct answer is:
Option C: The bases in nucleotides are attached to a pentose sugar moiety by a glycosidic linkage.
Each species has a characteristic set of chromosome number called- a)Aneuploid
- b)Monoploid
- c)Euploid
- d)Polyploid
Correct answer is option 'B'. Can you explain this answer?
Each species has a characteristic set of chromosome number called
a)
Aneuploid
b)
Monoploid
c)
Euploid
d)
Polyploid
|
|
Vijay Bansal answered |
Most human cells have 2 of each of the 23 homologous monoploid chromosomes, for a total of 46 chromosomes. A human cell with an extra set out of the 23 normal ones would be considered euploid. Euploid karyotypes would consequentially be a multiple of the haploid number, which in humans is 23.
DNA replication occurs during which part of the cell cycle?- a)G2 phase
- b)Dividing phase
- c)S phase
- d)G1 phase
Correct answer is option 'C'. Can you explain this answer?
DNA replication occurs during which part of the cell cycle?
a)
G2 phase
b)
Dividing phase
c)
S phase
d)
G1 phase
|
|
Rajat Kapoor answered |
During Mitosis, DNA is replicated during the S phase (Synthesis phase) of Interphase. Interphase is basically the daily life cycle of the cell. Cells spend most of their life in Interphase before Mitosis occurs (M phase).
Assertion: UAA codon is a termination codon.Reason: If in a mRNA, a termination codon is present, the protein synthesis stops abruptly whether the protein synthesis is complete or not.- a)Both Assertion and Reason are false.
- b)Both Assertion and Reason are true and the Reason is not the correct explanation of the Assertion.
- c)Both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
- d)None of these
Correct answer is option 'C'. Can you explain this answer?
Assertion: UAA codon is a termination codon.
Reason: If in a mRNA, a termination codon is present, the protein synthesis stops abruptly whether the protein synthesis is complete or not.
a)
Both Assertion and Reason are false.
b)
Both Assertion and Reason are true and the Reason is not the correct explanation of the Assertion.
c)
Both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
d)
None of these
|
|
Neha Sharma answered |
UAA of mRNA do not code for any amino acids so it is a termination codon. If termination codon is present on mRNA, the protein synthesis stops abruptly at that point.
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