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question_answer1)
Directions : (1 - 5) |
Read the passage given below and answer the following questions. |
DNA as an acidic substance present in nucleus was first identified by Friedrich Meischer in 1869. He named it as 'Nuclein'. However, due to technical limitation in isolating such a long polymer intact, the elucidation of structure of DNA remained elusive for a very long period of time. Wilkin and Franklin, 1953 got very fine X-ray photographs of DNA. It was only in 1953 that James Watson and Francis Crick, based on the X-ray diffraction data produced by Maurice Wilkins and Rosalind Franklin, proposed a very simple but famous Double Helix 3D model for the structure of DNA. One of the hallmarks of their proposition was specific base pairing between the two strands of polynucleotide chains. However, this proposition was also based on the observation of Erwin Chargaff 1950 that for a double stranded DNA, the ratios between Adenine and Thymine and Guanine and Cytosine are constant and equals one. The base pairing confers a very unique property to the polynucleotide chains. They are said to be complementary to each other, and therefore if the sequence of bases in one strand is known then the sequence in other strand can be predicted. Also, if each strand from a DNA i.e., parental DNA acts as a template for synthesis of a new strand, the two double stranded DNA i.e., daughter DNA thus, produced would be identical to the parental DNA molecule. Because of this, the genetic implications of the structure of DNA became very clear. |
DNA is
A)
An alkaline substance done
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B)
An acidic substance done
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C)
Semi acidic substance done
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D)
Semi alkaline substance done
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question_answer2)
X ray photographs of DNA is performed by which of the following scientist
A)
Friedrich Meischer, 1869 done
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B)
Watson and Crick, 1953 done
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C)
Wilkin and Franklin, 1953 done
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D)
Erwin Chargaff, 1950 done
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question_answer3)
In double stranded DNA, adenine and thymine are
A)
Always constant done
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B)
Adenine is more than thymine done
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C)
Adenine is less than thymine done
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D)
Never be constant done
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question_answer4)
Both DNA strands in eukaryotic cell are
A)
Complementary to each other done
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B)
Antiparallel in nature done
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C)
Specific base pairing is present done
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D)
All of the above done
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question_answer5)
Both parental DNA strands act as _________ for the synthesis of a new DNA strands i.e., daughter DNA
A)
Identical done
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B)
Template done
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C)
Coding done
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D)
Antagonistc done
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question_answer6)
Directions : (6 - 10) |
Read the passage given below and answer the following questions. |
In eukaryotes, DNA organisation is much more complex. There is a set of positively charged, basic proteins called histones. A protein acquires charge depending upon the abundance of amino acids residues with charged side chains. Histones are rich in the basic amino acid residues lysines and arginines. Both the amino acid residues carry positive charges in their side chains. Histones are organised to form a unit of eight molecules called as histone octamer. Histones : \[{{H}_{1}},\,\,{{H}_{2}}A,\,\,{{H}_{2}}B,\,\,{{H}_{3}}\]and \[{{H}_{4}}\]. These are always basic proteins. The negatively charged DNA is wrapped around the positively charged histone octamer to form a structure called nucleosome or nu body. DNA connecting two adjacent nucleosome is called interbead or linker DNA. It bearr \[{{H}_{1}}\]histone protein or plugging or marker protein. A typical nucleosome contains 200 bp of DNA helix. Nucleosomes constitute the repeating unit of a structure in nucleus called chromatin, thread-like stained i.e., coloured bodies seen in nucleus. The nucleosomes in chromatin are seen as 'beads-on-string' structure when viewed under electron microscope (EM). The beads-on-string structure in chromatin is packaged to form chromatin fibers that are further coiled and condensed at metaphase stage of cell division to form chromosomes. The packing of chromatin, at higher level requires additional set of proteins that collectively are referred to as Non-histone Chromosomal (NHC) proteins (negatively charged). |
Histone protein of DNA is
A)
Positively charged done
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B)
Basic in nature done
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C)
Acidic in nature done
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D)
Both [a] and [b] done
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question_answer7)
Histones protein are rich in which type of amino acids
A)
Tyrosine and Tryptophan done
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B)
Glycine and Proline done
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C)
Arginine and Lysine done
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D)
Methionine and Cystine done
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question_answer8)
Association between DNA and histones proteins is referred as
A)
Chondrosome done
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B)
Mesosome done
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C)
Lomasome done
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D)
Nucleosome done
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question_answer9)
Which histone protein acts as linker or interbreed DNA
A)
\[{{H}_{1}}\] done
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B)
\[{{H}_{2}}A\] done
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C)
\[{{H}_{2}}B\] done
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D)
\[{{H}_{3}}\] done
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question_answer10)
A typical nucleosome contain how many base pairs of DNA helix
A)
50 base pairs done
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B)
100 done
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C)
150 done
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D)
200 done
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question_answer11)
Directions : (11 - 15) |
Read the passage given below and answer the following questions. |
The unequivocal proof that DNA is the genetic material came from the experiments of Alfred Hershey and Martha Chase (1952). They worked with viruses that infect bacteria called bacteriophages. The bacteriophage attaches to the bacteria and its genetic material then enters the bacterial cell. The bacterial cell treats the viral genetic material as if it was its own and subsequently manufactures more virus particles. They worked to discover whether it was protein or DNA from the viruses that entered the bacteria. They grew some viruses on a medium that contained radioactive phosphorus (P32) and some others on medium that contained radioactive sulfur (S35). Viruses grown in the presence of radioactive phosphorus contained radioactive DNA but not radioactive protein because DNA contains phosphorus but protein does not. Similarly, viruses grown on radioactive sulfur contained radioactive protein but not radioactive DNA because DNA does not contain sulfur. Radioactive phages were allowed to attach to E. coli bacteria. Then, as the infection proceeded, the viral coats were removed from the bacteria by agitating them in a blender. The virus particles were separated from the bacteria by spinning them in a centrifuge. Bacteria which was infected with viruses that had radioactive DNA were idioactive, indicating that DNA was the material that passed from the virus to the bacteria. Bacteria that were infected with viruses that had radioactive proteins were not radioactive. This indicates that proteins did not enter the bacteria from the viruses. DNA is therefore the genetic material that is passed from Virus to Bacteria. |
Bacteriophages are
A)
Viruses that infect bacteria done
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B)
Viruses that infect plant cell done
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C)
Viruses that infect animal cell done
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D)
Viruses that infect cyanobacteria done
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question_answer12)
Which type of radioactive sulphur is used in the above paragraph
A)
\[{{S}^{32}}\] done
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B)
\[{{S}^{33}}\] done
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C)
\[{{S}^{34}}\] done
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D)
\[{{S}^{35}}\] done
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question_answer13)
Role of blender in the above experiment is
A)
Removal of bacterial coat from the virus done
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B)
Removal of Viral bacterial coat from the bacteria done
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C)
Removal of cell wall of bacteria done
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D)
Removal of cell membrane of bacteria done
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question_answer14)
Separation of virus particles from the bacteria is performed by
A)
Blender done
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B)
Centrifuge done
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C)
Electrophoresis done
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D)
Ultrasound done
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question_answer15)
Radioactive DNA and radioactive protein in the above paragraph have
A)
\[{{S}^{35}}\]and \[{{P}^{32}}\]respectively done
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B)
\[{{S}^{35}}\]and \[{{S}^{35}}\] respectively done
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C)
\[{{P}^{32}}\]and \[{{P}^{32}}\] respectively done
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D)
\[{{P}^{32}}\] and \[{{S}^{35}}\]respectively done
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question_answer16)
Directions : (16 - 20) |
Read the passage given below and answer the following questions. |
A gene is defined as the functional unit of inheritance. Though there is no ambiguity that the genes are located on the DNA, it is difficult to literally tRNA or rRNA molecule also define a gene. However by defining a cistron as a segment of DNA coding for a polypeptide, the structural gene in a transcription unit could be said as monocistronic (e.g., eukaryotes) or polycistronic (e.g., prokaryotes). In eukaryotes, the monocistronic structural genes have interrupted coding sequences - the genes in eukaryotes are split genes or intervening sequences (IVS) or Junk DNA. The coding sequences or expressed sequences are defined as exons. Exons are said to be those sequence that appear in mature or processed RNA. The exons are interrupted by introns. Introns or intervening sequences do not appear in mature or processed RNA. The split-gene arrangement further complicates the definition of a gene in terms of a DNA segment. Inheritance of a character is also affected by promoter and regulatory sequences of a structural gene. Hence, sometime the regulatory sequences are loosely defined as regulatory genes, even though these sequences do not code for any RNA or protein. |
Split genes or Intervening sequence (IVS) or Junk DNA is the feature of
A)
Prokaryotes done
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B)
Eukaryotes done
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C)
Both of the above done
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D)
None of the above done
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question_answer17)
A cistron is a segment of DNA coding for a
A)
Polysaccharide done
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B)
Polypeptide done
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C)
Polynucleotide done
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D)
Lipid done
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question_answer18)
The coding sequence in the eukaryotic DNA is referred as
A)
Introns done
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B)
Exons done
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C)
Recon done
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D)
Muton done
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question_answer19)
In polycistronic, DNA has how many structural gene(s)
A)
One gene done
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B)
Two genes done
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C)
Three genes done
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D)
Many genes done
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question_answer20)
A segment of DNA codes for single polypeptide is referred as
A)
Monocistronic done
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B)
Dicistronic done
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C)
Tricistronic done
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D)
Polycistronic done
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question_answer21)
Directions : (21 - 25) |
Read the passage given below and answer the following questions. |
99.9 per cent of base sequence among humans is the same. It is these differences in sequence of DNA which make every individual unique in their phenotypic appearance. If one aims to find out genetic differences between two individuals or among individuals of a population, sequencing the DNA every time would be a daunting and expensive task. Imagine trying to compare two sets of \[3\text{ }\times \text{ }{{10}^{9}}\] base pairs. DNA fingerprinting is a very quick way to compare the DNA sequences of any two individuals. DNA fingerprinting involves identifying differences in some specific regions in DNA sequence called as repetitive DNA, because in these sequences, a small stretch of DNA is repeated many times. These repetitive DNA are separated from bulk genomic DNA as different peaks during density gradient centrifugation. The bulk DNA forms a major peak and the other small peaks are referred to as satellite DNA. Depending on base composition (A : T rich or G:C rich), length of segment, and number of repetitive units, the satellite DNA is classified into many categories, such as micro- satellites (1-6 bp), mini-satellites (11-60 bp) etc. These sequences normally do not code for any proteins, but they form a large portion of human genome. These sequence show high degree of polymorphism and form the basis of DNA fingerprinting. Since DNA from every tissue such as blood, hair-follicle, skin, bone, saliva, sperm etc., from an individual show the same degree of polymorphism, they become very useful identification tool in forensic applications. Further, as the polymorphisms are inheritable from parents to children, DNA fingerprinting is the basis of paternity testing, in case of disputes. |
How many percent of base sequence are similar in the humans
A)
70% done
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B)
80% done
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C)
90% done
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D)
99.9% done
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question_answer22)
Repetitive DNA are separated from bulk genomic DNA by
A)
Electrophoresis done
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B)
Density gradient centrifugation done
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C)
Southern blotting done
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D)
Northern blotting done
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question_answer23)
Microsatellite is composed of
A)
1 to 6 base pairs done
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B)
2 to 8 base pairs done
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C)
3 to 10 base pairs done
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D)
4 to 12 base pairs done
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question_answer24)
Minisatellite has how many base pairs
A)
9 to 49 base pairs done
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B)
11 to 60 base pairs done
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C)
15 to 70 base pairs done
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D)
20 to 80 base pairs done
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question_answer25)
DNA fingerprinting helps in the study of
A)
Forensic applications done
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B)
Paternity testing done
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C)
Biological father or mother done
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D)
All of the above done
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question_answer26)
Directions : (26 - 30) |
Read the passage given below and answer the following questions. |
Nucleic acid is the genetic material of all organisms without exception. In majority of organisms this is deoxyribonucleic acid or DNA. In order to cut the DNA with restriction enzymes, it needs to be in pure form, free from other macro molecules. Since the DNA is enclosed within the membranes, we have to break the cell open to release DNA along with other macromolecules such as RNA, proteins, polysaccharides and also lipids. This can be achieved by treating the bacterial cells or plant or animal tissue with enzymes such as lysozyme (bacteria), cellulase (plant cells), chitinase (fungus) etc. As genes are located on long molecules of DNA interwined with proteins such as histones. The RNA can be removed by treatment with ribonuclease whereas proteins can be removed by treatment with protease. Other molecules can be removed by appropriate treatments and purified DNA ultimately precipitates out after the addition of chilled ethanol. This can be seen as collection of fine threads in the suspension. |
Nucleic acid is fragmented by which of the following enzyme:
A)
Ligases done
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B)
Proteases done
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C)
Nucleases done
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D)
Polymerases done
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question_answer27)
The most extensively used bacteria in genetic engineering is
A)
Bacillus done
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B)
Clostridium done
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C)
Escherichia done
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D)
Salmonella done
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question_answer28)
Assertion: In recombinant DNA technology, human genes are often transferred into bacteria or yeast. |
Reason: Both bacteria and yeast multiply very fast to form huge population which expresses the desired gene. |
A)
Assertion and reason both are correct statements and reason is correct explanation for assertion. done
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B)
Assertion and reason both are correct statements but reason is not correct explanation for assertion. done
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C)
Assertion is correct statement but reason is wrong statement. done
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D)
Assertion is wrong statement but reason is correct statement. done
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question_answer29)
Basic principle of developing transgenic plants and animals is to introduce the gene of interest into the nucleus of
A)
somatic cell done
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B)
vegetative cell done
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C)
germ cell done
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D)
body cell done
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question_answer30)
During the process of isolation of DNA, chilled ethanol is added to
A)
precipitate DNA done
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B)
break open the cell to release DNA done
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C)
facilitate action of restriction enzymes done
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D)
remove proteins such as histones done
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question_answer31)
Directions : (31 - 35) |
Read the passage given below and answer the following questions. |
In 1928, Frederick Griffith, in a series of experiments with Streptococcus pneumoniae or Diplococus or Pneumococcus i.e., bacterium responsible for the disease pneumonia, witnessed a miraculous transformation in the bacteria. During the course of his experiment, a living organism i.e., bacteria had changed in physical form. When Streptococcus pneumoniae bacteria are grown on a culture plate, some produce smooth shiny colonies (S) while others produce rough colonies (R). This is because the S strain bacteria have a mucous i.e.. polysaccharide coat, while R strain does not. Mice infected with the S strain (virulent or pathogenic) die from pneumonia infection but mice infected with the R strain (nonvirulent or non-pathogenic) do not develop pneumonia. Griffith was able to kill bacteria by heating them. He observed that heat-killed S strain bacteria injected into mice did not kill them. When he injected a mixture of heat-killed S and live R bacteria, the mice died. Moreover, he recovered living S bacteria from the dead mice. |
What happened when heat killed S cells along with live R cells were injected into mice?
A)
Mice survived and showed live S cells done
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B)
Mice died and showed, S cells done
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C)
Mice survived and showed live R cells done
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D)
Mice died and showed dead S cells done
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question_answer32)
In microbial genetics, which one is referred to as 'Griffith Effect'?
A)
Conjugation done
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B)
Transduction done
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C)
Transformation done
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D)
Sexudation done
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question_answer33)
The beginning of understanding genetic transformation in bacteria was made by
A)
Frederick Griffith done
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B)
Hershey and Chase done
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C)
Watson and Crick done
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D)
T. H. Morgan done
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question_answer34)
Transformation process in genetics was discovered by
A)
Frederick Griffith done
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B)
Watson and Crick done
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C)
Meselson and Stahl done
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D)
Hershey and Chase done
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question_answer35)
In 1928 F. Griffith performed his experiment on which of the following bacterium :
A)
Escherichia coli done
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B)
Salmonella typhi done
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C)
Streptococcus pneumonia done
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D)
Vibrio cholera done
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