a bacteriophage known as φ ×174 has
5386 nucleotide
Bacteriophage lambda has
48502 bp
Escherichia coli has
4.6 × 106 bp
haploid content of human DNA
3.3 × 109 bp
adenine
purine
cytosine
pyrimidine
guanine
purine
thymine
pyrimidine
uracil
pyrimidine
A nitrogenous base is linked to the OH of ____ pentose sugar
1’C
phosphate group is linked to OH of 5' C of a nucleoside through_____
phosphoester linkage
The backbone of a polynucleotide chain is formed due to
sugar and phosphate
isolation of DNA was done by
Friedrich Meischer
The pitch of the helix of DNA is
3.4nm
the distance between a bp in a helix is approximately
0.34nm
which scientist gave the central dogma
Francis Crick
The negatively charged DNA is wrapped around the positively charged histone octamer to form a structure called
nucleosome
typically nucleosome contains ___bp
200
typically 2 nucleosome can have_____bp
400
The packaging of chromatin at higher level requires additional set of proteins that collectively are referred to as
non histone chromosomal protein
nucleosome = DNA+___
histone octamer
densely stained part of chromatin
heterochromatin
transcriptionally inactive
heterochromatin
light stained chromatin part
euchromatin
transcriptionally active
euchromatin
in 1928 which scientist indirectly proved that the genetic material is sort of heat stable
Frederick Griffith
in the experiment of transforming principle which organism was used
Streptococcus pneumoniae
Frederick Griffith is associated with
transforming principle
Oswald Avery, Colin MacLeod and Maclyn McCarty were associated with
biochemical nature of transforming principle
alfred hershey and martha chase were associated with
unequivocal proof
when the bacteriophage is grown in radioactive suplhur then on centrifugation the suphur is retained in
supernatant
when the bacteriophage is grown in radioactive phosphorus then on centrifugation the phosphorus is retained in
bacteria
generally bacteriophages have dsDNA exception to this is
QB bacteriophage
ex of RNA viruses
QB bacteriophage and Tobacco Mosaic virus
better for storage of genetic material
DNA
better for transmission of genetic information
RNA
who gave the initial idea of DNA replication
Watson and Crick
Matthew Meselson and Franklin stahl are associated with
experimental proof of DNA replication
organism used in the proof of semiconservative DNA replication
E.coli
compound used as density gradient in the experiment to prove semiconservative DNA replication
Caseium chloride (CsCl)
who used radioactive thymidine to prove the semiconservative DNA replication
Taylor and collegues
the radioactive thymidine to detect new chromosome was performed on which plant
Vicia faba
enzyme responsible for DNA replication
DNA-dependent DNA polymerase
E.coli can replicate within
18 minutes
E.coli can divide within
20 minutes
during replication ______ in addition to acting as substrate also provide energy for polymerisation
deoxyribonucleoside triphosphate
in replication _____ serves dual function
deoxyribonucleoside triphosphate
replication of template strand from 3’-5’ is
continuous
replication of template strand from 5’-3’ is
discontinuous
the discontinuously formed fragments are joined by
DNA ligase
A failure in cell division after DNA replication results into
polyploidy
the process of transcription requires an enzyme
DNA dependent RNA polymerase
during transcription 3’-5’ strand acts as
template strand
during transcription 5’-3’ strand acts as
coding strand
All the reference point while defining a transcription unit is made with
coding strand
The promoter is said to be located towards_____ of structural gene
5’(upstream)
The terminator is said to be located towards_____ of structural gene
3’(downstream)
the DNA sequence coding for tRNA or rRNA molecule is called
gene
sequences which appears in mature RNA
exons
sequences do not appear in mature or processed RNA
introns
regulatory genes
do not code for RNA or proteins
which type of RNA provides template
mRNA
which type of RNA brings amino acid
tRNA
which type of RNA reads the genetic code
tRNA
which type of RNA plays structural role
rRNA
which type of RNA plays catalytic role
rRNA
RNA polymerase uses_____ as substrate
nucleoside triphosphate
RNA polymerase is only capable of catalysing the process of
elongation
transcribes rRNA
RNA polymerase I
transcribes 28S, 18S, 5.8S
RNA polymerase I
transcribes precursor of mRNA
RNA polymerase II
transcribes tRNA
RNA polymerase III
transcribes 5srRNA
RNA polymerase III
transcribes snRNA
RNA polymerase III
unusual nucleotide (methyl guanosine triphosphate) this is
capping
capping is done on which end
5’
adenylate residues (200-300) added this is
tailing
tailling is done on which end
3’
The process of _______ requires transfer of genetic information from a polymer of nucleotides to synthesise a polymer of amino acid
translation
who argued that since there are only 4 bases and if they have to code for
20 amino acids, the code should be made up of three nucleotides
a permutation combination of 43 (4 × 4 × 4) would generate 64 codon
George Gamow
who was instrumental in synthesising RNA molecules with defined combinations
of bases (homopolymers and copolymers)
Har Gobind Khorana
who’s cell-free system for protein synthesis finally helped the code to be deciphered
Marshal Nirenberg
_______ was helpful in polymerising RNA with defined sequences in a template independent manner
Severo Ochoa enzyme
Severo Ochoa enzyme aka
polynucleotide phosphorylase
Some amino acids are coded by more than one codon, hence the code is
degenerate
UUU
phenylalanine
AUG
methionine
CCC
proline
AAA
lysine
GGG
glycine
From the very beginning of the proposition of code, it was clear to _______ that there has to be a mechanism to read the code and also to link it to the amino acids, because amino acids have no structural specialities to read the code uniquely.
Francis Crick
which scientist postulated the presence of tRNA
Francis Crick
type of RNA which initiates the process of translation
initiator tRNA
2o structure of tRNA
clover leaf
actual structure of tRNA
inverted L
1st step of translation is
aminoacylation of tRNA
The ribosome consists of structural RNAs and about _____different proteins
eighty
when the _____ subunit of ribosome encounters the mRNA the process of translation begins
smaller
the _____ subunit of ribosome continues the elongation of the amino acid chain
larger
tRNA aka
solubleRNA