During translation initiation in prokaryotes, a GTP molecule is needed in
association of 50 S subunit of ribosome with initiation complex
formation of formyl-met-tRNA
binding of 30 S subunit of ribosome with mRNA
association of 30 S-mRNA with formyl-met-tRNA
Which one of the following triplet codes, is correctly matched with its specificity for an amino acid in protein synthesis or as ‘start’ or ‘stop’ codon?
UAC- Tyrosine
UCG- Start
UUU- Stop
UGU- Leucine
What would happen if in a gene encoding polypeptide of 50 amino acids, 25th codon (UAU) is mutated to UAA?
A polypeptide of 25 amino acids will be formed
A polypeptide of 24 amino acids will be formed
Two polypeptides of 24 and 25 amino acids will be formed
A polypeptide of 49 amino acids will be formed
In the genetic code dictionary, how many codons are used to code for all the 20 essential amino acids?
60
20
64
61
In a mutational event, when adenine is replaced by guanine, it is a case of
Frame shift mutation
Transcription
Transition
Transversion
During transcription, if the nucleotide sequence of the DNA strand that is being coded is ATACG, then the nucleotide sequence in the mRNA would be
TATGC
TCTGC
UAUGC
UATGC
Crossing over that results in genetic recombination in higher organisms occurs between
sister chromatids of a bivalent
non-sister chromatids of a bivalent
two daughter nuclei
two different bivalents
The following ratio is generally constant for a given species:
A+G/C+T
T+C/G+A
G+C/A+T
A+C/T+G
The telomeres of eukaryotic chromosomes consist of short sequences of
Thymine rich repeats
Cytosine rich repeats
Adenine rich repeats
Guanine rich repeats
During replication of a bacterial chromosome DNA synthesis starts from a replication origin site and
RNA primers are involved
Is facilitated by telomerase
Moves in one direction of the site
Move in bi-directional
In transgenics, expression of transgene in target tissue is determined by
enhancer
transgene
promoter
reporter
E. coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because:
The lac operon is constitutively active in these cells
They cannot synthesize functional betagalactosidase
In the presence of glucose, E.coli cells do not utilize lactose
They cannot transport lactose from the medium into the cell
During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is that sequence called?
AAAT box
TATA box
GGTT box
CAAT box
Which one of the following makes use of RNA as a template to synthesize DNA?
DNA polymerase
RNA polymerase
Reverse transcriptase
DNA dependant RNA polymerase
Telomerase is an enzyme which is a
simple protein
RNA
ribonucleoprotein
repetitive DNA
One gene –one enzyme hypothesis was postulated by
Hershley and Chase
A. Garrod
Beadle and Tatum
R. Franklin
In which mode of inheritance do you expect more maternal influence among the offspring?
Cytoplasmic
Y–linked
X–linked
Autosomal
The restriction enzymes are used in genetic engineering because
they can degrade harmful proteins
they can join different DNA fragments
they can cut DNA at specific base sequence
they can nucleases that cut DNA at variable sites
Producing a “giant mouse” in the laboratory was possible through
Gene synthesis
Gene manipulation
Gene duplication
Gene mutation
The first successfully cloned mammal that gained worldwide publicity was
Chance, a bull
Dolly, a sheep
Molly, a sheep
Polly, a sheep
One bacterium which is extensively engineering work in plants is
Agrobacterium tumifaciens
Bacillus coagulens
Xanthomonas citri
Clostridium septicum
Which of the following properties make plasmids suitable vectors for gene cloning?
Plasmids often carry antibiotic resistance gene
Plasmids can shuttle between procaryotic and eucaryotic cells
Plasmids are small circular DNA molecules with their own replication origin site
Plasmids are small circular DNA molecules that integrate with host chromosomal DNA
Which of the following cut DNA at specific sites?
Restriction endonuclease (E-coli)
Ligase
Exonuclease
Alkaline phosphate
A mutat strain of T4 –Bacteriophage, R-II, fails to lyse the E-coli. , but when two strains R-IIr and R-IIy are mixed then they lyse the E-coli. What may be possible reason?
Bacteriophage transform in wild
It is not mutated
Both strains have similar cistrons
Both strains have different cistrons
The content of genetic information per virion per strand of nucleic acid is about
1 to 50 kilo bases
2 to 100 kilo bases
3 to 300 kilo bases
400 to 800 kilo bases
Mendel obtained wrinkled seeds in pea due to deposition of sugars instead of starch. It was due to which enzyme
Amylase
Invertase
Diastase
Absence of starch branching enzyme
Triticale is obtained by crossing wheat with
Oat
Barley
Maize
Rye
Change in sequence of nucleotide in DNA is called as
mutagen
mutation
recombination
translation
The transgenic animals are those which have
Foreign DNA in some of its cells
Foreign DNA in all its cells
Foreign RNA in all its cells
DNA and RNA both in the cells
Which of the following reunites the exon segments after RNA splicing?
RNA polymerase
RNA primase
RNA ligase
RNA proteoses
An enzyme that joins the ends of two strands of nucleic acid is a_____
polymerase
synthetase
helicase
ligase
Introduction of one or more genes into an organism which normally does not possess them or their deletion by using artificial means (not by breeding) comes under.
molecular biology
cytogenetics
genetic hybridization
genetic engineering
Genetic engineering is possible because
We can see DNA by electron microscope
We can cut DNA at specific sites by endonucleases like DNAase I
Restriction endonucleases purified from bacteria can be used in vitro
The phenomenon of transduction in bacteria is well understood
Restriction endonucleases are
Synthesized by bacteria as part of their defence mechanism
Use for in vitro DNA synthesis
Used in genetic engineering for ligating two DNA molecules
Present in mammalian cells for degradation of DNA when the cell dies
Recombinant DNA is achieved by cleaving the pro DNAs by
Exonucleases
Ligase
Restriction endonuclease
Primase
The chemical knives of DNA are
Polymerases
Endonucleases
Transcriptases
Lligases
Which of the following is related to genetic engineering?
Plastid
Plasmid
Heterosis
Mutation
Nucleus of a donor embryonal cell/somatic cell is transferred to an enucleated egg cell. Then after the formation of organisms, what shall be true?
Organisms will have extranuclear genes of the donor cell
Organism will have extra nuclear genes of recipient cell
Organisms will have extra nuclear genes of both donor and recipient cell
Organism will have nuclear genes of recipient
If a diploid cell is treated with colchicines then it becomes
triploid
tetraploid
diploid
monoplod
Manipulation of DNA in genetic engineering became possible due to the discovery of
Restriction endonuclease
DNA lagase
Transcriptase
Primase
Which of the following enzymes are used to join bits of DNA ?
Ligase
Primase
DNA polymerase
endonuclease
Which of the following discoveries resulted in a Nobel prize?
Genetic engineering
X- rays induce sex-linked recessive lethal mutations
Cytoplasmic inheritance
Recombination of linked genes
Which one of the following bacteria has found extensive use in genetic engineering work in plants?
Agrobacterium tumefaciens
Clostridium septicum
Xanthomonas citri
Bacillus coagulens
Restriction endonucleases
Are present in mammalian cells for degradation of DNA when the cell dies
Are used in genetic engineering for ligating two DNA molecules
Are used for in vitro DNA synthesis
Are synthesized by bacteria as part of their defence mechanism
A nutritionally wild type organism, which does not require any additional growth supplement is known as
Phenotype
Holotype
Auxotroph
Prototroph
The Ti plasmid is often used for making transgenic plants. This plasmid is found in
Azotobacter
Rhizobium of the roots of leguminous plants
Agrobacterium
Yeast as a 2 µm plamid
Production of human protein in bacteria by genetic engineering is possible because :
the human chromosome can replicate in bacterial cell
the mechanism of gene regulation is identical in humans and bacteria
bacterial cell can carry out the RNA splicing reactions
the genetic code is universal
Which of the following is generally used for induced mutagenesis in crop plants?
X-rays
UV (260nm)
Gamma rays (from cobalt 60)
Alpha particles
Restriction endonuclease
Cuts the DNA molecule at specific sites
Restricts the synthesis of DNA inside the nucleus
Synthesizes DNA
Cuts the DNA molecules randomly
Amino acid sequence, in protein synthesis is decided by the sequence of
mRNA
cDNA
tRNA
rRNA