Your cart is empty.
Practice each question, then open the answer or worked solution.
Rising of dough is due to:
Ans: Rising of dough is due to the presence of CO2. Yeast present in the dough consumes the sugar present in the dough and releases carbon dioxide and ethanol. The released CO2 gets trapped inside the dough due to the presence of gluten in it. Thus, the dough has risen.
Hence, option (b) is the correct choice.
Which of the following enzymes catalyze the removal of nucleotides from the ends of DNA?
Ans: Exonuclease is the enzyme which removes nucleotides from the ends of the DNA.
Hence, option (b) is the correct choice.
The transfer of genetic material from one bacterium to another through the mediation of a viral vector is termed as:
Ans: The transfer of genetic material from one bacterium to another through the mediation of a viral vector is termed Transduction.
Hence, option (a) is the correct choice.
Which of the given statements is correct in the context of visualizing DNA molecules separated by agarose gel electrophoresis?
Ans: While doing gel electrophoresis DNA is stained with Ethidium bromide and then after gel electrophoresis, they are seen under exposure to UV light. DNA cannot be seen in visible light either with staining or without staining.
Hence, option (d) is the correct choice.
'Restriction' in Restriction enzyme refers to:
Ans: The enzyme which is obtained from bacteria that can recognize specific base sequences in DNA and restrict (cut) the DNA at the specific site. Bacteria use restriction enzymes to protect themselves from a viral infections such as bacteriophages. When viruses infect the bacteria, the phage inserts its DNA into the bacterial cell for replication at that time the restriction enzyme prevents the replication of the phage DNA by cutting it into pieces. Because of this ability, they are named restriction enzymes. It hydrolyses a phosphodiester bond on one of the two DNA strands.
Hence, option (d) is the correct choice.
Which of the following is not required in the preparation of a recombinant DNA molecule?
Ans: Restriction endonuclease recognize a specific site of a DNA sequence and cleaves the DNA at the target sequence.
DNA ligase attaches two DNA strands.
E. coli is a bacteria which is used in various experiments.
Hence, option (d) is the correct choice.
In agarose gel electrophoresis, DNA molecules are separated based on recognizes their:
Ans: Gel electrophoresis is the method by which mixtures of DNA, RNA, or proteins are separated according to their molecular size.
Hence, option (c) is the correct choice.
The most important feature in a plasmid to serve as a vector in a gene cloning experiment is:
Ans: The most important feature in a plasmid to serve as a vector in thatene cloning experiments is the origin of replication (ori). It is a sequence from where replication starts. When a piece of DNA is linked to this ori it replicates the DNA and makes multiple copies within the host cell as well as it also controls the copy number of the linked DNA.
Hence, option (a) is the correct choice.
While isolating DNA from bacteria, which of the following enzymes is not required?
Ans: Deoxyribonuclease is the enzyme that is not used while isolating DNA from bacteria.
Lysozyme is used for breaking the membranes which surround DNAs.
Ribonuclease is used for removing RNA.
Protease is used for removing protein.
Hence, option (c) is the correct choice.
Which of the following contributed in popularising the PCR (polymerase chain reactions) technique?
Ans: Thermostable DNA is obtained from Thermus aquaticus bacteria. It remains active at high temperatures thus helping in the denaturation of DNA during PCR.
Hence, option (d) is the correct choice.