Multiple Choice QuestionsWhich of the following is commonly used as a vector for introducing a DNA fragment in human lymphocytes?
Retrovirus
Ti plasmid
pBR 322
λ phage
A.
Retrovirus
Retrovirus is commonly used as vector for introducing a DNA fragment in human lymphocyte.
Gene therapy: Lymphocyte from the blood of the patient are grown in culture outside the body, a functional gene is introduced by using a retroviral vector, into these lymphocyte.
AGGTATCGCAT is a sequence from the coding strand of a gene. What will be the corresponding sequence of the transcribed mRNA?
AGGUAUCGCAU
UGGTUTCGCAT
UCCAUAGCGUA
ACCUAUGCGAU
A.
AGGUAUCGCAU
Coding strand and mRNA has same nucleotide sequence except, ‘T’ – Thymine is replaced by ‘U’–Uracil in mRNA.
Many ribosomes may associate with a single mRNA to form multiple copies of a polypeptide simultaneously. Such strings of ribosomes are termed as
Polysome
Polyhedral bodies
Nucleosome
Plastidome
A.
Polysome
The phenomenon of association of many ribosomes with single m-RNA leads to the formation of polyribosomes or polysomes or ergasomes.
Which of the following is true for nucleolus?
Larger nucleoli are present in dividing cells
It is a membrane-bound structure
It is a site for active ribosomal RNA synthesis
It takes part in spindle formation
C.
It is a site for active ribosomal RNA synthesis
The nucleolus is a non-membranous structure and is a site of r-RNA synthesis.
The experimental proof for semiconservative replication of DNA was first shown in a
Fungus
Bacterium
Virus
Plant
B.
Bacterium
Semi-conservative DNA replication was first shown in Bacterium Escherichia coli by Matthew Meselson and Franklin Stahl.
Which of the following pairs is wrongly matched?
Starch synthesis in pea: Multiple alleles
ABO blood grouping: Co-dominance
T.H. Morgan: Linkage
XO type sex determination: Grasshopper
A.
Starch synthesis in pea: Multiple alleles
Starch synthesis in pea is controlled by a pleiotropic gene.
All of the following are part of an operon except
an operator
structural genes
a promoter
an enhancer
D.
an enhancer
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