molecular basis of inheritance Flashcards
1
Q
number of nucleotides in phix174
A
5386
2
Q
number of bp in bacteriophage lambda
A
48502
3
Q
number of bp in e coli
A
4.6x10^6
4
Q
adenosine, guanosine,cytidine and uridine are
A
nucleosides
5
Q
the additional OH grp of RNA is at
A
2’ position of ribose
6
Q
dna as an acidic substance was first identified by federick meischer in
A
1869
7
Q
double helix model proposed in
A
1953
8
Q
pitch of the helix of dna
A
3.4 nm
9
Q
how many base pairs in each turn of dna
A
10
10
Q
distance between a bp in the helix of dna
A
0.34 nm
11
Q
ventral dogma of biology proposed by
A
francis crick
12
Q
dimension of typical nucleus
A
app. 10^-6
13
Q
length of ecoli dna
A
1.36 mm
14
Q
number of bp in a nucleosome
A
2000
15
Q
year range of work of ostwald avery, collin macleod and maclynmccarty was
A
1933-1944
16
Q
harshey and chase experiment in which year
A
1952
17
Q
three steps in harshey and chase experiment
A
infection
blending
centrifugation
18
Q
two eg for viruses that use rna as genetic material
A
qb bacteriophage
tobacco mosaic virus
19
Q
stability as one of the properties of genetic material was evident in whose experiment
A
griffith experiment
20
Q
what makes rna labileand easily degradable
A
extra oh at 2’
21
Q
semiconservative replication was first shown in
A
ecoli
22
Q
experiment on semiconservatic replication was done on which year
A
1958
23
Q
e coli divides in how many minutes
A
20 min
24
Q
similar experiment for semiconservative replication was done by taylor and colleagues using radioactive thymidine on vicia faba(faba beans) in which yesr
A
1958
25
rate of polymerisation in e coli
2000 bp / s
26
who provides energy for replication of dna
deoxyribonucleoside triphosphate
27
the two terminal phosphates in deoxyribonucleoside triphosphate are ____ phosphates, same as in the case of ___
high-energy
| ATP
28
direction of polymerisation of dna dependent dna polymerase
5’ to 3’
29
three regions of transcription unit
promotor
structural gene
terminator
30
promotor is located at
5’ end of structural gene
31
functional unit of inheritance
gene
32
the dna sequence coding for ___ and ___ molecule also define a gene
tRNA and rRNA
33
monocistronic mostly in
eukaryotes
34
defining a cistron as a
segment of dna coding for a polypeptide
35
the __ complicates the definition of a gene in terms of dna segment
split gene arrangement
36
symbol of initiation factor
sigma
37
symbol of termination factor
rho
38
there are atleast __ RNA polymerases in the nucleus other than those found in the organelles
three
39
RNA polymerase I transcribes
rRNA (28s,18s,5.8s)
40
rRNA (28s,18s,5.8s) is transcribed by
RNA polymerase I
41
RNA polymerase II transcribes
hnRNA
42
RNA polymerase III transcribes (3)
tRNA, 5srRNA, snRNA
43
tRNA, 5srRNA, snRNA are transcribed by
RNA polymerase III
44
hnRNA is transcribed by
RNA polymerase II
45
capping of hnRNA is done at __ by adding
5’
| methyl guanosine triphosphate
46
adenylate residues are addded to hnRNA during tailing, in a ___ ___ manner
template independent
47
the chemical method developed by ____ was instrumental in synthesising RNA molecules with defined combination of bases (homopolymers and copolymers)
Har Gobind Khorana
48
cell free system ofor protein synthesis is given by
Marshell Neirenberg
49
severo ochoa enzyme is a
polynucleotide phosphate
50
UUU codes for
phenylalanine
51
the code is universal. exception to this rule is found in ___ and ___
mitochondrial codons
| some protozoans
52
deletion mutations are also called
frameshift mutations
53
tRNA wa searlier called
sRNA
54
the ribosomes consist of
RNAs and Proteins
55
how many different types of proteins can be seen in ribosome
80
56
which rna in bacteria is ribozyme
23S rRNA
57
during translation, amino acida are added one by one, translated into polypeptide sequences dictated by ___ and represented by ___
DNA
| mRNA
58
at the end of translation, a ___ binds to the stop codon, terminating translation and releasing the complete polypeptide from the ribosome
release factor
59
which are the four levels at which regulation of gene expression could be exerted in eukaryotes
transcriptional level (formation of primary transcript)
processing level (regulation of splicing)
transport of mrna from nucleus to cytoplasm
translational level
60
the operator regions is adjacent to the ___ elements in most operons
promoter
61
in most cases the sequences of the operon bind a ___ protein
repressor
62
elucidation of lac operon done by
Francois Jacob (geneticist) and Jacque Monad (biochemist)
63
in lac operon, a ___ ____ ____ is regulated by common promoter and regulatory genes
polycistronic structural gene
64
in lac operon, a polycistronic structural gene is regulated by common promoter and regulatory genes. such arrangement is very common in __
bacteria
65
the i in i gene is derived from the word
inhibitor
66
three structural genes of lac operon
z, y and a
67
z gene of lac operon codes for
beta-galactosidase
68
in lac operon, beta-galactosidase is coded by which gene
z gene
69
in lac operon, y gene codes for
permease
70
permease increases
permeability of the cell to beta galactosidase
71
permease is coded by which structural gene
y gene
72
in lac operon, a gene codes for
transacetylase
73
transacetylase is coded by
gene a
74
lactose is the substrate for which enzyme
beta galactosidase
75
the repressor protein binds to the ___ region of the operon
operator region
76
regulation of lac operon by repressor is referred to as
negative regulation
77
It is the sequence of ___ in DNA that determines the genetic information of a given organism
Bases
78
A very ambitious project of sequencing human genome was launched in the year ___
1990
79
Human genome project was called a
Mega project
80
Human genome is said to have approximately ___ bp
3x10^9
81
The total estimated cost of HGP was approximately __ with __ dollars per bp
9 billion US dollars
| 3 dollars per bp
82
How many books with how many words and pages would be required to store the information of DNA
3300 books with 1000 pages and each page having 1000 letters
83
HGP was closely associated with the rapid development of a new area in biology called
Bioinformatics
84
Appr. How many genes are there in human DNA
20,000-25,000
85
How many bp make up human DNA
3 billion
86
Full form of ELSI
Ethical, legal and social issues
87
For how long did the HGP last
13 year
88
HGP was coordinated by which two companies
U.S department of energy
| National institute of health
89
During the early years of HGP, the ___ became a major partner
The Wellcome Trust (U.K)
90
Countries that contributed to HGP
Japan, France , Germany, China and othes
91
The HGP was completed in
2003
92
Which two plants were the non human model that were sequenced
Rice
| Arabidopsis
93
Which insect was the non human model that were sequenced
Drosophila
94
Eg for a free living non pathogenic nematode
Caenorhabditis elegans
95
Give 5 eg for non human models that were sequenced
```
Bacteria
Yeast
Caenorhabditis elegans
Plants (2)
Drosophila
```
96
EST full form
Expressed sequence tags
97
What are EST
All the genes that are expressed as RNA
98
Tge commonly used hosts for cloning were (2)
Bacteria and yeast
99
The commonly used vectors used for cloning were
BAC
| YAC
100
The fragments were sequenced using automated DNA sequencers that worked in the principle of a method developed by
Frederick Sanger
101
Who was credited for developing method for determination of amino acid sequences in proteins
Frederick Sanger
102
The sequence of chromosome 1 was completed in
May 2006
103
From the result of HGP, the human genome contains ___ bp
3164.7 million bp
104
From the result of HGP, The avg gene consists of __ bases
3000
105
Largest human gene is? How many bases does it have
Dystrophin
| 2.4 million bases
106
From the result of HGP, the total number of genes is estimated at ___ -much lower that previous estimates of ___ to ___ genes
30,000
| 80,000 to 1,40,000
107
Almost ____% of nucleotide bases are exactly the same in all people
99.9%
108
The functions are unknown for over __% of tge discovered genes
50%
109
Less than __% of the genome codes for proteins
2%
110
___ sequence make up very large portion of human genome
Repeated sequence
111
Repetative sequences are stretches of DNA sequences that are repeated many times, sometimes ___ to __ times
Hundred to thousand times
112
Repeetitive sequences have no direct __ functions but they shed light on __, __ and __
Coding
Chromosome structure, dynamics and evolution
113
Which chromosome has most genes. How many?
Chromosome 1
| 2968
114
Which chromosome has least genes. How many
Y chromosome
| 231
115
Scientists have identified about how many locations where single base DNA differences occure in humans
1.4 million
116
Full form of SNP
Single nucleotide polymorphism
117
SNPs are also called
Snips
118
In how many base sequences of DNA would theere be differences
3x10^6
119
Repetitive DNA are separated from the bulk DNA as different peaks during density gradient centrifugation. The ___ forms a major peak and tge other small peaks are referred to as __
Bulk DNA
| satellite DNA
120
What is the basis of DNA fingerprinting
Variable Number of Tandem Repeat (VNTR) polymorphism
121
Allelic sequence variation is decribed as a DNA polymorphism if more than __ variant(allele) at a locus occurs in human population with a frequency greater than__
0.01
122
What is DNA Polymorphism
If an Inheritable mutation is observed in a population at high frequency, it is reffered to as DNA polymorphism
123
The probability of inheritable variations to be observed in non-coding DNA sewuence would be lower/higher as mutation in these sequences may/may not have any impact in an individual’s reproductive ability
Higher
| May not
124
Dna fingerprinting was developed by who
Alec Jeffreys
125
Alec jaffrey used __ as probe that shows ___
Satellite DNA
| very high degree of polymorphism
126
What is VNTR
Satellite dna that shows very high degree of polymorphism
127
Southern blot hybridisation using __ as probe
Radiolabelled VNTR
128
Detection of hybridised Dna fragments was done by what method
Autoradiography
129
The VNTR belongs to a class of ___ DNA referred to as ___
Satellite dna
| Mini-satellite
130
The suze of VNTR varies in size from __ to __
0.1 to 20kb
131
After hybridisations, the bands give a characteristic pattern for an individual DNA. It differs from individual to individual in a population except in the case of
Monozygotic (identical) twins
132
The sensitivity of dna fingerprinting was increased by use of
PCR
133
The tRNA binds to specific amino acids at one end and pairs through __ bonding
H-bonding
134
Which is the primary step for regulation of transcription
Regulation of transcription
135
Genetic material of T2 bacteriophage
DNA
136
When was Wilkins, Watson and Crick awarded nobel prize
1962
137
Which component of dna gives it the negative charge
Phosphate
138
Chargaff’s rule is applied only to ___ and not applicable to __ and __
dsDNA
| ssDNA and RNA
139
What was the two chargaff’s rules
A+G = T+C
A+T/G+C = constant for species
140
Nature of dna of phix174
ssDNA
141
Nature of DNA in lambda phage
dsDNA
142
Nature of dna in ecoli
dsDNA
143
Nature of DNA in prokaryotic cell
dsDNA, circular and naked(without histones)
144
Histones have high/low molecular weight
Low
145
Types of histones in nucleosome (4)
H2A, H2B, H3 and H4
146
H1 hostone is ____ part of nucleosome and H1 is present in ___ or __ DNA
Not the part of
Linker or spacer DNA
147
In each nucleosome tge DNA is wrapped for about ____ turns
1 3/4
148
What is chromatosome
Nucleosome and H1 histone in liner or spacer DNA is called chromatosome
149
The heavy isotope of N is
Non radioisotopic
150
Who unwinds the strands of DNA
DNA helicase/ unwindase/ unzipping enzyme
151
Due to unwing of DNA strands, tension or strain is created in the distal ends of dna, which is relieved by__. It has __ and __ activity
DNA Gyrase/ Topoisomerase
| Cut and seal
152
To prevent rewinding and recoiling of the opened dna, ___ attaches to tamplate strands
Single strand binding proteins (ssb)
153
Using rna primer, ___ adds nucleotides to the replicating dna
DNA polymerase III
154
After adding nucleotides, ___ degrade rna primer and replace it with dna
DNA polymerase I
155
Cistron is equivalent to
Structural gene
