Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Genetics > Molecular Basis Of Inheritance > Flashcards

Molecular Basis Of Inheritance Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

_____acts as a genetic material in some viruses .

A

RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

RNA mostly functions as a __.

A

Messenger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The determination of complete nucleotide sequence of human genome during last decade has set in a new era of _____.

A

Genomics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

DNA is a long polymer of ___.

A

Deoxyribonucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The length of DNA is usually defined as _____ present in it .

A

Number of nucleotides (or base pairs present )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A pair of nucleotides are referred to as ____.

A

Base pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A bacteriophage - phi * 174 has ____nucleotides .

A

5386

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Bacteriophage -lambda hs ____ base pairs

A

48502

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

E.coli has _____BASE pairs .

A

4.6 * 10_6 ( 4600000)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Haploid content of human DNA has __base pairs .

A

3.3 * 10_9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which bacteriophage has 5386 base pairs ?

A

Phi*174

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A __has 3 components -a N base , a PENTOSE sugar and a phosphate grp .

A

Nucleotide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Name the N bases that are purines .

A

Adenine

Guanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Name the N bases that are pyrimidine .

A

Cytosine
Uracil
Thymine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In case of pyrimidines , __is common in both DNA and RNA .

A

Cytosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In case of pyrimidines , __is present in RNA ,in place of ____ .

A

Uracil

Thymine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

A N base is linked to the __of __C pentose sugar through a __linkage to form a ___ .

A

OH
1’ C
N glycosidic linkage
Nucleoside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Name a nucleoside which is exclusively present in DNA and in RNA ?

A

DNA- deoxythymidine

RNA - uridine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Adenosine and deoxyadenosine are __.

A

Nucleosides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When a phosphate grp is linked to ____ of ____C of a ____through ____linkage , a corresponding nucleotide is formed .

A

OH
5’C
Nucleoside
PHOSPHOESTER linkage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

2 nucleotides are lined through __ to form a _____ .

A

3’-5’ phosphodiester linkage

Dinucleotide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

A polynucleotide is formed has at one end a __ at 5 ‘ end of sugar , which is referred to as 5’ -end of polynucleotide chain .

A

Phosphate moiety

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

At The other end of polynucleotide chain , the sugar has a ____ of 3 C grp which is referred to as 3’ end of the polynucleotide chain .

A

Free OH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The back bone of a polynucleotide chain is formed due to __and ____ . The ____project from the backbone .

A

Sugar
Phosphates
N bases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In RNA ,every nucleotide residue has an additional ____ present at ____ position in the RIBOSE .

A

-OH grp

2’position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Other name of thymine -

A

5-methyl uracil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

DNA as an acidic substance present in the nucleus was first identified by ____in ___ .

A

Friedrich meischer

1869

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Name given by friedrich meischer to DNA .

A

Nuclein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

It was only in ____that ___and ____ based on ____ proposed a very simple but famous double helix model for the structure of DNA .

A

1953
James Watson
Francis crick
X-diffraction data

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

X-ray diffraction data was produced by _and _.

A

Maurice Wilkins

Rosalind franklin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

One of the hallmarks of the proposition given by Francis and rick was -

A

Base pairing btw 2 strands of polynucleotide chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The proposition given by Francis and crick was based on the observation of _____

A

Erwin chargaff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Observation of chargaff -

A

For double stranded DNA ,

Ratios btw ADENINE and THYMINE and GUANINE and CYTOSINE are constant and equals 1 .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The salient features of double helix structure of DNA -

A

Made of 2 polynucleotide , where backbone is sugar-phosphate and bases project INSIDE .
Chains have anti-parallel polarity
Bases are paired through H-bonds
2 chains are coiled in a right-handed fashion . Pitch of helix is 3.4nm .
The plane of one base pair stacks over the other in double helix .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Adenine forms ____ H-bonds with thymine and cytosine forms ____ H-bonds with guanine .

A

2

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Always a purine comes ____To pyrimidine .

A

Opposite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

The pitch of the helix is ____ , and there are __ bp in each turn .

A

3.4nm

10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

The distance btw a bp in a helix is ______ .

A

0.34nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Which 2 features confer stability of the helical structure .

A

1) H-bonding

2) plane of one base pair stacks over the other in double helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

____ proposed the Central Dogma in molecular biology .

A

Francis crick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What does the central dogma state ?

A

Genetic info flows from DNA —> RNA —>protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

In some ____ , the flow of info is in the reverse direction , ie from RNA to DNA .

A

Viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Length of DNA double helix -

A

2.2 m ( 6.6* 109 bp. * 0.34 *10-9 m/bp)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

No of base pairs in humanDNA .

A

6.6 * 10_9 bp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Length of E.coli DNA -

A

1.36 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

How is the DNA arranged in a prokaryotic cell such as E. Coli ?

A

The DNA is not scattered throughout the cell . DNA being negatively charged is held with some proteins (+ve charged ) in a region termed as NUCLEOID .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

The DNA in _____ is organised in large loops held by proteins in prokaryotes .

A

Nucleoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

The type of DNA organisation in eukaryotes -

A

Complex
There is a set of +ve charged , basic proteins called HISTONES .histones are organised to form a unit of 8 molecules called HISTONE OCTAMER .the -ve charged DNA is wrapped around the +ve histone octamer to form a nucleosome .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

The proteins ( which constitute the histone octamer ) acquire charge depending upon the _____

A

Abundance of amino acids residues with charged side chains .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Histones are rich in ___amino acid residues __and ____ .

A

Basic
Lysine
Arginine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Amino acid residues , arginine and lysine carry _____charge in their ____.

A

+ve

Side chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Histones are arranged to form a unit of ______ molecules .

A

8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

The -ve dna is wrapped around + histone octamer to form a structure called _____.

A

Nucleosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

A typical nucleosome contains ______ bp of DNA helix .

A

200

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Nucleosomes constitute the repeating unit of a structure in nucleus called ________ .

A

Chromatin (thread -like coloured bodies seen in nucleus )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

The _____ are seen as BEADS ON STRING when viewed under electron microscope .

A

Nucleosomes ( in chromatin )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

The beads on string. Structure(of nucleosome) in chromatin is packaged to form ______ that are further coiled and condensed at _____ of cell division to form _______.

A

Chromatin fibres
Metaphase
Chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

The packaging of chromatin at higher level req additional set of proteins that collectively are referred to as _______ .

A

Non-histone chromosomal proteins ( NHC )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

In a typical nucleus , some region of chromatin are loosely packed and stains light . They are called _______ .

A

Euchromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

The chromatin that is more densely packed and stain dark are called ____.

A

Heterochromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

_____is said to be transcriptionally active chromatin , whereas _____is inactive .

A

Euchromatin

Heterochromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Discovery of nuclein By meischer and principles of inheritance by Mendel were almost at the same time but ____ took long to be discovered and proven .

A

DNA acts as the genetic material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

By ____ , the quest to determine the mechanism for genetic inheritance had reached the molecular level .

A

1926

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

In ____ , ______ gave the transforming principle .

A

1928

Fredrick Griffith

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Fredrick Griffith in a series of experiments with _____witnessed a miraculous transformation in. The bacteria .

A

Streptococcus pneumoniae ( bacteria responsible for causing pneumonia )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

During the course of Griffith’s experiment , bacteria had changed in ____form .

A

Physical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

When streptococcus pneumoniae are grown in a culture plate , some produce ______ while others produce ______ .

A

Rough colonies

Smooth shiny colonies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Smooth shiny colonies were produced because the S-strain bacteria have ______while R-strain does not .

A

Mucous polysaccharide coat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Effect of injecting S -strain , R- strain , S-strain heat killed , S-strain heat killed + R-strain .

A

S—— mice die
R——mice live
S-heat killed —— mice live
S-heat killed + R-strain ——mice die

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Griffith recovered _____from the dead mice .

A

LIVING S-bacteria ( though he injected heat killed S -strain + Liv R strain )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What did Griffith conclude ?

A

R-strain bacteria had somehow been transformed by the heat -killed S-strain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

According to Griffith , some transforming principle transferred from heat killed S strain , had enabled ____ to _____ and become virulent .

A

R-strain

Synthesise a smooth polysaccharide coat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

__was not defined from Griffith’s experiments .

A

Biochemical nature of genetic material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Prior to the work of __, ____and ____ , the genetic material was thought to be a protein .

A

Oswald Avery
Colin Macleod
Maclyn McCarty

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Avery , Macleod and McCarty worked to determine the ____.

A

Biochemical nature of ‘transforming principle “ in Griffith’s experiment .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Avery , Macleod and McCarty worked in the year ___.

A

1933- 1944 ( after Griffith - 1928)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What did Avery , macleod and McCarty do ?

A

They purified biochemicals (proteins ,DNA and RNA ) from heat-killed S-cells to see which ones could transform live R cells into S- cells .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Avery , Macleod and McCarty discovered that DNA alone from ____ caused ____ to become _____ .

A

S-bacteria
R-bacteria
Transformed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Avery , Mac and Mac also discovered that ___and ____ did not affect transformation .

A

Protease (protein -digesting enzyme )

RNase ( RNA digesting enzyme )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

Digestion with ______ did inhibit transformation .

A

DNase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

The unequivocal proof that DNA is the genetic material came from __ in the year ____ .

A

Hershey and chase

1952

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

Alfred Hershey and Martha chase worked on _____ .

A

Bacteriophage ( viruses that infect bacteria )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Hershey and chase worked to discover whether it was __or ___ from ___ that __.

A

Protein
DNA
Viruses
Entered the bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

In Hershey’s experiment , the ___attaches to the bacteria and its genetic material enters _____ , which treats the viral genetic material as if ______ and subsequently manufactures more viruses .

A

Bacteriophage
Bacterial cell
It was its own

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

Hershey and chase grew some viruses on a medium that contained _____ and some others on medium containing ___>

A

Radioactive phosphorus

Radioactive sulphur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Viruses grown in presence of radioactive phosphorus contained ___but not __ becoz ____ . And viruses grown on radioactive sulphur Contained _________ but not ___.

A 
Radioactive DNA 
Radioactive proteins 
DNA contains P but protein does not .
Radioactive Protein 
Rad DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

After radioactive labeling of DNA and proteins in chase’s exp , the next step was -

A

Infection

Radioactive phages were allowed to attach to E.coli bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What were the 3 steps in Hershey and chase’s exp ?

A

1) infection - radioactive phages were allowed to attach to E.coli
2) blending - the viral coats were removed from the bacteria by agitating them in a blender .
3) centrifugation - the virus particles were separated from bacteria by spinning in a centrifuge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

______ indicated that DNA was the genetic material that passed from virus to bacteria in Hershey and chase’s exp .

A

Bacteria which was infected with virus that had radioactive DNA were radioactive .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

In chase and Hershey’s exp , bacteria that were infected with viruses that had radioactive protein were _____.

A

Not radioactive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

In _____, RNA is the genetic material .

A

SOME viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Give a few examples of viruses where RNA is the genetic material .

A

TMV

QB bacteriophage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

A molecule that can act as a genetic material must fulfill the following criteria -

A

1) able to generate its own replica ( replication )
2) stable chemically and structurally
3) must provide the scope for slow changes (mutation) that are req for evolution .
4) able to express itself in the form of Mendelian chars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

__ has the ability to direct its duplication (1st criteria of genetic material ) . __fail to fulfill this criteria .

A

Both DNA and RNA

Proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

_____as one of the properties of genetic material was very evident in Griffith’s transformation principle ‘ itself that ______ .

A

Stability

Heat which killed the bacteria did not destroy some of the properties of genetic material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

The 2 strands of DNA being complementary if separated by heating come together when appropriate conditions are provided . T/F

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

____grp present at every nucleotide in RNA is a reactive grp and makes RNA LABILE and EASILY DEGRADABLE .

A

2’-OH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

RNA is also known to be ____ , hence reactive .

A

Catalytic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

DNA as compared to RNA is chemically __and structurally _____ .

A

Less reactive

More stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

______confers additional stability to DNA .

A

Presence of thymine at the place of uracil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

__is able to mutate .

A

Both DNA and RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

__DNA /RNA mutates at a faster rate .WHY ?

A

RNA

Being unstable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Viruses having __and ____ mutate and evolve faster .

A

RNA genome

Shorter lifespan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

____can directly code for the synthesis of PROTEINS ., hence can easily express the characters .

A

RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

_is dependent on ____for synthesis of proteins .

A

DNA

RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

_has evolved around RNA .

A

Protein synthesizing machinery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

DNA being ____ is preferred for ____ . For ____ RNA is better .

A

More stable
Storage of genetic info
Transmission of genetic info

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

___Was the first genetic material . __evolved around it

A

RNA

Essential life processes ( metabolism , translation , splicing )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

RNA being ___ was unstable . Therefore DNA has evolved from RNA with chemical modifications that make it more stable .

A

Catalytic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

DNA being _____ further resists changes by evolving a process of repair .

A

Double stranded and having complementary strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

“ it has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material “ . This statement was given by ____ in the year ___ .

A

Watson and crick

1953

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

It is now roved that DNA replicates ____.

A

Semiconservatively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

Semiconservative nature of DNA replication was shown in ___ and subsequently in ____ , such as ____ and ______ .

A

E. Coli
Higher organisms
Plants
Human cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

_____and _____ performed the exp to prove semiconservative nature of DNA replication n the year ____ .

A

Mathew messelson
Franklin. Stahl
1958

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

Meselson and stahl grew E.COLI in a medium containing ___ as the only __source for many generations . The result was ____ .

A

15-NH4Cl ( 15-N is the heavy isotope of N)
N2
15-N was incorporated into newly synthesised DNA (as well as other N containing compounds )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

The heavy DNA molecule in meselson and Stahl’s exp could be distinguished from the normal DNA by ____ in ____ .

A

Centrifugation

CsCl ( cesium chloride ) density gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

N-15can be separated from N-14 only based on _____ . Why ?

A

Only based on densities .

Becoz it is not a radioactive isotope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

The 2nd step in meselson’s exp -

A

Transferred the cells into a medium with normal 14-NH4Cl and took samples at various definite time intervals as the cells multiplied and extracted the DNA that remained as double-stranded helices .
The various samples were separated independently on CsCl gradients to measure the densities of DNA .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

In meselson’s exp , DNA that was extracted from the culture one generation after the transfer from 15N to 14N medium (ie,. After 20 mins ) had a _density .

A

Hybrid or Intermediate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

DNA extracted from the culture after another generation , after 40 mins was composed of _____ .

A

Equal amts of hybrid DNA and of ‘light’ DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

Exp similar to meselson and stahl’s were performed by ______ in ____ .

A

Taylor and colleagues

1958

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

Exp similar to meselson’s involving use of ____ to detect distribution of newly synthesised DNA in the chromosomes was performed on ____ by TAYLOR .

A 
Radioactive thymidine 
Vicia faba ( faba beans )
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

In living cells , such as E. Coli , the process of replication requires a set of ____ .

A

Catalysts ( enzymes )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

The main enzyme used for replication is called -

A

DNA dependent DNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

Why is the main enzyme of replication called - DNA dependent DNA polymerase ?

A

Since it uses a DNA template to catalyse the polymerisation of deoxynucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

DNA dependent DNA polymerase is a __enzyme as it has to catalyse polymerisation of a large number of nucleotides in a very short time .

A

Highly efficient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

E .coli that has only _____ bp completes the process of replication within ____ minutes . Which means avg rate of polymerisation has to be approx __.

A

4.6*10_6
18 mins
2000bp/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

These polymerase have to be highly ___ becoz any mistake during replication would result into ____.

A

Accurate

Mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

Energetically ,replication is a __process .

A

Very expensive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

___serves dual purpose in replication .

A

Deoxyribonucleoside triphosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

Which 2 purposes does depxyribonucleoside triphosphate serve in replication ?

A

1) acts as the substrate
2) provide energy for polymerisation rxn ( the 2 terminal phosphates in a deoxynucleoside triphosphates are high energy phosphates , same as case of ATP )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

In addition to DNA dependent DNA polymerase , many additional enzymes are also req to complete replication . T/F

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

For __DNA molecules , since the 2 strands of DNA cannot be separated in its entire length due t ___ , the replication occurs within a small opening of the DNA helix , referred to as _____ .

A

Long
Very high energy requirement
Replication fork

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

The DNA dependent -DNA polymerase catalyse polymerisation in _directions . Which ?

A

Only in 1 direction

5’—-> 3’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

____creates an additional complication at the replication fork . What is its consequence ?

A

1 direction polymerisation by DNA dependent DNA polymerase ( 5’—>3’)
On one strand , the replication is continuous and on the other it is discontinuous .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

Replication is continuous on template strand with polarity ____ and discontinuous on template strand with polarity ___.

A

3’—>5’

5’—>3’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
137
Q

The discontinuously synthesised fragments are later joined by the enzyme _____.

A

DNA ligase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
138
Q

The ___on their own cannot initiate the process of replication .

A

DNA polymerases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
139
Q

The replication initiates randomly at any place in DNA . T/F

A

F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
140
Q

The definite region in E.coli DNA where the replication originates are -

A

Origin of replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
141
Q

It is because of the req of ori that a piece of DNA if needed to be propagated during recombinant DNA procedures , req a ____ .

A

Vector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
142
Q

The vectors provide _____ .

A

Ori

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
143
Q

In eukaryotes , the replication of DNA takes place at ___ of the cell cycle .

A

S-phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
144
Q

A failure in cell division after DNA replication results into ___ . Therefore _and ____ must be highly cocordinated .

A

Polyploidy ( a chromosomal anomaly )

DNA replication and cell division cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
145
Q

The process of ___ from one strand of __into ___ is termed as TRANSCRIPTION .

A

Copying info
DNA
RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
146
Q

The principle of ____ governs the process of transcription . Exception to this is ___ .

A

Complementarity

Adenosine complements now forms base pair with uracil instead of thymine .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
147
Q

Major Difference btw replication and transcription -

A

Replication -total DNA gets duplicated

Transcription-only a segment of DNA and only one of the strands is copied into RNA .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
148
Q

Defining the boundaries is necessary to demarcate the region and the strand of DNA in transcription/replication .

A

Transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
149
Q

Similarity btw transcription and replication .

A

Complementarity governs both processes

But in transcription , adenosine forms bp with uracil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
150
Q

Why both the strands are not copied during transcription -

A

1) if both strands act as template , they would code for RNA molecule with diff sequences , and in turn if they code for proteins , the sequence of amino acids in the proteins would be diff .
Hence, one segment of DNA would be coding for 2 diff proteins , complicating the genetic info .
2) the 2 RNA molecules if produced simultaneously would be complementary to each other , hence would form a DOUBLE STRANDED RNA . This would prevent RNA from being translated into proteins and the exercise of transcription would become futile .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
151
Q

What would happen if the 2 RNA’s are produced simultaneously ?

A

They would be complementary to each other , hence forming double stranded RNA . This would prevent RNA from being translated into proteins , thus the whole process of transcription would become futile .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
152
Q

A transcription unit in DNA is defined primarily by the 3 regions in the DNA :

A

A promoter
The structural gene
A terminator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
153
Q

The strand that has polarity __Acts as the template , and is also referred to as template strand .

A

3’—>5’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
154
Q

The strand which has polarity ___ coding strand .

A

5’—>3’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
155
Q

Why is there a convection in defining the 2 strands of DNA ?

A

Since the 2 strands have opposite polarity and the DNA -dependent RNA polymerase also catalyses polymerisation in only one direction , ie. 5’—> 3’ , one strand acts as template and the one with opposite polarity acts as coding .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
156
Q

The DNA dependent RNA polymerase catalyses polymerisation in ___ direction .

A

Only 1

5’—>3’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
157
Q

Which strand has the sequence same as RNA (except thymine at the place of uracil ) ?

A

Coding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
158
Q

Which strand is displaced during transcription ?

A

Coding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
159
Q

The strand which does not code for anything is called -

A

Coding strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
160
Q

All the reference point while defining a transcription unit is made with ___ .

A

Coding strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
161
Q

The ____and____flank the structural gene in a transcription unit .

A

Promoter

Terminator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
162
Q

The promoter is said to be located towards the __End of the ___gene . ( wrt coding strand )

A

5’ - upstream

Structural gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
163
Q

It is the ___that provides binding site for RNA polymerase and it is the presence of a ____ in a transcription unit that also defines the template and coding strands .

A

DNA sequence

Promoter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
164
Q

By switching the position of ____with ____ , the definition of coding and template strands could be reversed .

A

Promoter

Terminator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
165
Q

The terminator is located towards the __end of the coding strand and it usually defines the ____ of the process of transcription .

A

3’ end -downstream

End

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
166
Q

The ____ is located upstream and____downstream of the coding strand .

A

Promoter

Terminator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
167
Q

There are additional regulatory that may be present further upstream and downstream to the _____.

A

Promoter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
168
Q

A ___is defined as the functional unit of inheritance .

A

Gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
169
Q

The DNA sequence coding for ____or ____also define a gene .

A

tRNA

rRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
170
Q

By defining a cistron as a segment of DNA coding for polypeptide , the structural gene in a transcription unit could be said as ___ or ____.

A

Monocistronic

Polycistronic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
171
Q

Monocistronic gene is found mostly in __and polycistronic gene is found mostly in _____ .

A

Eukaryotes

Prokaryotes or bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
172
Q

In eukaryotes ,the monocistronic structural genes have ____ coding sequence - the genes in EUKARYOTES are ______ .

A

Interrupted

Split

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
173
Q

The coding sequences or EXPRESSED sequences are defined as _____.

A

Exons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
174
Q

Exons are said to be those sequences that appear in _____.

A

Mature or processed RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
175
Q

The exons are interrupted by _____.

A

Introns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
176
Q

___do not appear in mature or processed RNA .

A

Introns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
177
Q

The ___arrangement further complicates the definition of a gene in terms of a DNA segment .

A

Split gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
178
Q

Inheritance of a char are also affected by _____and ____sequnces of a structural gene .

A

Promoter

Regulatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
179
Q

Sometimes the regulatory sequnces are loosely defined as ____ though they do not code for any RNA or proteins .

A

Regulatory genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
180
Q

In bacteria , there are _major types of RNA .

A

3
M-RNA
T-RNA
R-RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
181
Q

All the 3 RNAs are needed to synthesise a ___ in a cell .

A

Protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
182
Q

The ___provides the template , __brings amino acids and reads the genetic code , ___ play structural and catalaytic role during translation .

A

mRNA
tRNA
rRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
183
Q

There is a single ____ that catalyses transcription of all types of RNA in bacteria.

A

DNA dependent RNA polymerase

184
Q

RNA polymerase binds to ___ and initiates transcription . This process is called ____.

A

Promoter

Initiation

185
Q

RNA polymerase uses ___ as substrate and polymerises in a ____ fashion following the rule of ____ .

A

Nucleosides triphosphates
Template dependent
Complementarity

186
Q

___ somehow also facilitates opening of helix and continues ELONGATION during transcription .

A

RNA polymerase

187
Q

Once the RNA polymerase reaches the ____end , the ____ falls off .

A

Terminator end

Nascent RNA

188
Q

What results in the termination of transcription ?

A

When the RNA polymerase reaches the terminator region , the nascent RNA falls off , so also the RNA polymerase . This results in termination .

189
Q

_____ remains bound to the enzyme RNA polymerase during elongation in transcription .

A

Only a short stretch of RNA

190
Q

How is the RNA polymerase able to catalyse all the 3 steps of transcription : initiation , elongation , termination ?

A

It is only capable of catalysing elongation .

It associates transiently with initiation factor and termination factor to initiate and terminate .

191
Q

The RNA polymerase is only capable of catalysing ___during transcription .

A

Elongation

192
Q

RNA polymerase associates transiently with ____ and ____ .

A 
Initiation factor (sigma )
Termination ( rho )
193
Q

Association with sigma and rho factors alters _____ to either initiate or terminate .

A

The specificity of the RNA polymerase

194
Q

transcription and translation can be coupled in __.

A

Bacteria

195
Q

In bacteria , translation an sometimes begin before ___ .

A

The RNA is fully transcribed

196
Q

Why is trancscription and translation coupled in bacteria ?

A

1) mRNA does not require any processing to become active .
2) since transcription and translation take place in the same compartment ( there is no separation of cytosol and nucleus in bacteria )

197
Q

What are the complexities found in eukaryotes during transcription ?

A

1) at least 3 RNA polymerases in the nucleus ( in addition to the RNA polymerase found in cell organelles ). There is a clear cut division of labour btw the 3 RNA polymerases .
2) primary transcript contain both exons and introns and are non-functional .hence they are subjected to splicing .

198
Q

How many RNA polymerases are found in eukaryotes .

A

At least 3 in the nucleus

1 in the cell organnelles

199
Q

The RNA polymerase 1 transcribes ____ .

A

rRNAs - 28S , 18S , 5.8S

200
Q

RNA polymerase 3 is responsible for -

A

Transcription of tRNA , 5 srRNA , snRNAs (small nuclear RNAs)

201
Q

The RNA polymerase 2 transcribes ____.

A

Precursor of mRNA - hnRNA ( heterogenous nuclear )

202
Q

Introns are removed and exons are joined in a defined order by -

A

Splicing

203
Q

____undergoes additional processes called capping and tailing ( in addition to splicing ).

A

hnRNA

204
Q

In CAPPING , ___is added to _____end of hnRNA .

A

Methyl guanosine triphosphate - unusual NUCLEOTIDE

5’ end of hnRNA

205
Q

In tailing , ____ are added to __end of hnRNA , in a ____ manner .

A

Adenylate residues - 200-300
3’end
Template INDEPENDENT manner

206
Q

It is the ______ RNA that is transported out of the NUCLEUS for TRANSLATION .

A

Fully processes hnRNA - now called mRNA

After capping and tailing

207
Q

In ____, an unusual nucleotide is added .

A

Capping of hnRNA

Addition of methyl guanosine triphosphate

208
Q

How many adenylate residues are added in tailing ? In what manner .

A

200-300

Template -independent

209
Q

The process of splicing represents _____.

A

Dominance of RNA world

210
Q

During ____and ______ , a nucleic acid was copied to form another nucleic acid .

A

Replication

Transcription

211
Q

The process of translation req transfer of genetic info from a ____to form a ______ .

A

Polymer of nucleotides

Polymer of amino acids

212
Q

Complementarity exists btw nucleotides and amino acids . T/F

A

F
No complementarity btw nucleotides and amino acids .
This differentiates translation form transcription .

213
Q

It was ____ , a ____ 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 3 nucleotides .

A

George Gamow

Physicist

214
Q

The chemical methods developed by ____ instrumental in synthesizing RNA molecules with defined combinations of bases ( homopolymer s and copolymers ).

A

Har Gobind Khorana

215
Q

______ ‘s cell free system for protein synthesis finally helped the code to be deciphered .

A

Marshall nirenberg’s

216
Q

__enzyme was also helpful in polymer is int RNA with defined sequnces in a template independent manner .

A

Severo Ochoa - polynucleotide phosphorylase

217
Q

Finally a ___for genetic code was prepared .

A

Checker board

218
Q

Severo Ochoa was helpful in polymer is int RNA with defined sequnces in a __manner .

A

Template independent - ENZYMATIC SYNHESIS OF RNA

219
Q

Gorge Gamow , a physicist argued that since there are only __bases and if they have to code for ____ , the code should be made up of ____ .

A

4
20 amino acids
3 nucleotides

220
Q

Proof that the codon was triplet was given by -

A

Khorana

221
Q

_____finally helped the code to be deciphered .

A

Marshall nirenberg’s cell free system

222
Q

Salient features of genetic code -

A

1) codon is triplet
2) code is DEGENERATE
3) codon in mRNA is read in a CONTAGIOUS fashion
4) code is nearly universal
5) AUG has dual functions. initiator codon and codes for methionine
6) UAA, UAG, UGA - terminator codons

223
Q

____codons code for amino acids . ____ codons do not code for amino acids , hence the function as _____ .

A

61
3
Stop codons

224
Q

Why is the code called DEGENERATE ?

A

Some amino acids are coded by more than one codon

225
Q

Codon in mRNA is read in a contagious fashion . Meaning -

A

No punctuations

226
Q

From bacteria to humans , UUU would code for ___.

A

Phenylalanine (Phe)

227
Q

The codon is NEARLY universal . Exceptions to this -

A

Found in mitochondrial codons and in some protozoans

228
Q

Dual function of AUG -

A

Codes for methionine

Acts as initiator codon

229
Q

Terminator codons -

A

UAA
UAG
UGA

230
Q

Insertion or deletion of 1 or 2 bases changes the reading frame from the point of ____ . Such mutations are called -

A

Insertion or deletion

frameshift insertion or deletion mutations

231
Q

Insertion or deletion of ____ inserts or deletes in 1 or multiple codons , hence the reading frame remains unaltered from that point onwards .

A

3 or its multiple bases

232
Q

In living cells , such as E. Coli , the process of replication requires a set of ____ .

A

Catalysts ( enzymes )

233
Q

The main enzyme used for replication is called -

A

DNA dependent DNA polymerase

234
Q

Why is the main enzyme of replication called - DNA dependent DNA polymerase ?

A

Since it uses a DNA template to catalyse the polymerisation of deoxynucleotides

235
Q

DNA dependent DNA polymerase is a __enzyme as it has to catalyse polymerisation of a large number of nucleotides in a very short time .

A

Highly efficient

236
Q

E .coli that has only _____ bp completes the process of replication within ____ minutes . Which means avg rate of polymerisation has to be approx __.

A

4.6*10_6
18 mins
2000bp/s

237
Q

These polymerase have to be highly ___ becoz any mistake during replication would result into ____.

A

Accurate

Mutations

238
Q

Energetically ,replication is a __process .

A

Very expensive

239
Q

___serves dual purpose in replication .

A

Deoxyribonucleoside triphosphate

240
Q

Which 2 purposes does depxyribonucleoside triphosphate serve in replication ?

A

1) acts as the substrate
2) provide energy for polymerisation rxn ( the 2 terminal phosphates in a deoxynucleoside triphosphates are high energy phosphates , same as case of ATP )

241
Q

In addition to DNA dependent DNA polymerase , many additional enzymes are also req to complete replication . T/F

A

T

242
Q

For __DNA molecules , since the 2 strands of DNA cannot be separated in its entire length due t ___ , the replication occurs within a small opening of the DNA helix , referred to as _____ .

A

Long
Very high energy requirement
Replication fork

243
Q

The DNA dependent -DNA polymerase catalyse polymerisation in _directions . Which ?

A

Only in 1 direction

5’—-> 3’

244
Q

____creates an additional complication at the replication fork . What is its consequence ?

A

1 direction polymerisation by DNA dependent DNA polymerase ( 5’—>3’)
On one strand , the replication is continuous and on the other it is discontinuous .

245
Q

Replication is continuous on template strand with polarity ____ and discontinuous on template strand with polarity ___.

A

3’—>5’

5’—>3’

246
Q

The discontinuously synthesised fragments are later joined by the enzyme _____.

A

DNA ligase

247
Q

The ___on their own cannot initiate the process of replication .

A

DNA polymerases

248
Q

The replication initiates randomly at any place in DNA . T/F

A

F

249
Q

The definite region in E.coli DNA where the replication originates are -

A

Origin of replication

250
Q

It is because of the req of ori that a piece of DNA if needed to be propagated during recombinant DNA procedures , req a ____ .

A

Vector

251
Q

The vectors provide _____ .

A

Ori

252
Q

In eukaryotes , the replication of DNA takes place at ___ of the cell cycle .

A

S-phase

253
Q

A failure in cell division after DNA replication results into ___ . Therefore _and ____ must be highly cocordinated .

A

Polyploidy ( a chromosomal anomaly )

DNA replication and cell division cycle

254
Q

The process of ___ from one strand of __into ___ is termed as TRANSCRIPTION .

A

Copying info
DNA
RNA

255
Q

The principle of ____ governs the process of transcription . Exception to this is ___ .

A

Complementarity

Adenosine complements now forms base pair with uracil instead of thymine .

256
Q

Major Difference btw replication and transcription -

A

Replication -total DNA gets duplicated

Transcription-only a segment of DNA and only one of the strands is copied into RNA .

257
Q

Defining the boundaries is necessary to demarcate the region and the strand of DNA in transcription/replication .

A

Transcription

258
Q

Similarity btw transcription and replication .

A

Complementarity governs both processes

But in transcription , adenosine forms bp with uracil

259
Q

Why both the strands are not copied during transcription -

A

1) if both strands act as template , they would code for RNA molecule with diff sequences , and in turn if they code for proteins , the sequence of amino acids in the proteins would be diff .
Hence, one segment of DNA would be coding for 2 diff proteins , complicating the genetic info .
2) the 2 RNA molecules if produced simultaneously would be complementary to each other , hence would form a DOUBLE STRANDED RNA . This would prevent RNA from being translated into proteins and the exercise of transcription would become futile .

260
Q

What would happen if the 2 RNA’s are produced simultaneously ?

A

They would be complementary to each other , hence forming double stranded RNA . This would prevent RNA from being translated into proteins , thus the whole process of transcription would become futile .

261
Q

A transcription unit in DNA is defined primarily by the 3 regions in the DNA :

A

A promoter
The structural gene
A terminator

262
Q

The strand that has polarity __Acts as the template , and is also referred to as template strand .

A

3’—>5’

263
Q

The strand which has polarity ___ coding strand .

A

5’—>3’

264
Q

Why is there a convection in defining the 2 strands of DNA ?

A

Since the 2 strands have opposite polarity and the DNA -dependent RNA polymerase also catalyses polymerisation in only one direction , ie. 5’—> 3’ , one strand acts as template and the one with opposite polarity acts as coding .

265
Q

The DNA dependent RNA polymerase catalyses polymerisation in ___ direction .

A

Only 1

5’—>3’

266
Q

Which strand has the sequence same as RNA (except thymine at the place of uracil ) ?

A

Coding

267
Q

Which strand is displaced during transcription ?

A

Coding

268
Q

The strand which does not code for anything is called -

A

Coding strand

269
Q

All the reference point while defining a transcription unit is made with ___ .

A

Coding strand

270
Q

The ____and____flank the structural gene in a transcription unit .

A

Promoter

Terminator

271
Q

The promoter is said to be located towards the __End of the ___gene . ( wrt coding strand )

A

5’ - upstream

Structural gene

272
Q

It is the ___that provides binding site for RNA polymerase and it is the presence of a ____ in a transcription unit that also defines the template and coding strands .

A

DNA sequence

Promoter

273
Q

By switching the position of ____with ____ , the definition of coding and template strands could be reversed .

A

Promoter

Terminator

274
Q

The terminator is located towards the __end of the coding strand and it usually defines the ____ of the process of transcription .

A

3’ end -downstream

End

275
Q

The ____ is located upstream and____downstream of the coding strand .

A

Promoter

Terminator

276
Q

There are additional regulatory that may be present further upstream and downstream to the _____.

A

Promoter

277
Q

In living cells , such as E. Coli , the process of replication requires a set of ____ .

A

Catalysts ( enzymes )

278
Q

The main enzyme used for replication is called -

A

DNA dependent DNA polymerase

279
Q

Why is the main enzyme of replication called - DNA dependent DNA polymerase ?

A

Since it uses a DNA template to catalyse the polymerisation of deoxynucleotides

280
Q

DNA dependent DNA polymerase is a __enzyme as it has to catalyse polymerisation of a large number of nucleotides in a very short time .

A

Highly efficient

281
Q

E .coli that has only _____ bp completes the process of replication within ____ minutes . Which means avg rate of polymerisation has to be approx __.

A

4.6*10_6
18 mins
2000bp/s

282
Q

These polymerase have to be highly ___ becoz any mistake during replication would result into ____.

A

Accurate

Mutations

283
Q

Energetically ,replication is a __process .

A

Very expensive

284
Q

___serves dual purpose in replication .

A

Deoxyribonucleoside triphosphate

285
Q

Which 2 purposes does depxyribonucleoside triphosphate serve in replication ?

A

1) acts as the substrate
2) provide energy for polymerisation rxn ( the 2 terminal phosphates in a deoxynucleoside triphosphates are high energy phosphates , same as case of ATP )

286
Q

In addition to DNA dependent DNA polymerase , many additional enzymes are also req to complete replication . T/F

A

T

287
Q

For __DNA molecules , since the 2 strands of DNA cannot be separated in its entire length due t ___ , the replication occurs within a small opening of the DNA helix , referred to as _____ .

A

Long
Very high energy requirement
Replication fork

288
Q

The DNA dependent -DNA polymerase catalyse polymerisation in _directions . Which ?

A

Only in 1 direction

5’—-> 3’

289
Q

____creates an additional complication at the replication fork . What is its consequence ?

A

1 direction polymerisation by DNA dependent DNA polymerase ( 5’—>3’)
On one strand , the replication is continuous and on the other it is discontinuous .

290
Q

Replication is continuous on template strand with polarity ____ and discontinuous on template strand with polarity ___.

A

3’—>5’

5’—>3’

291
Q

The discontinuously synthesised fragments are later joined by the enzyme _____.

A

DNA ligase

292
Q

The ___on their own cannot initiate the process of replication .

A

DNA polymerases

293
Q

The replication initiates randomly at any place in DNA . T/F

A

F

294
Q

The definite region in E.coli DNA where the replication originates are -

A

Origin of replication

295
Q

It is because of the req of ori that a piece of DNA if needed to be propagated during recombinant DNA procedures , req a ____ .

A

Vector

296
Q

The vectors provide _____ .

A

Ori

297
Q

In eukaryotes , the replication of DNA takes place at ___ of the cell cycle .

A

S-phase

298
Q

A failure in cell division after DNA replication results into ___ . Therefore _and ____ must be highly cocordinated .

A

Polyploidy ( a chromosomal anomaly )

DNA replication and cell division cycle

299
Q

The process of ___ from one strand of __into ___ is termed as TRANSCRIPTION .

A

Copying info
DNA
RNA

300
Q

The principle of ____ governs the process of transcription . Exception to this is ___ .

A

Complementarity

Adenosine complements now forms base pair with uracil instead of thymine .

301
Q

Major Difference btw replication and transcription -

A

Replication -total DNA gets duplicated

Transcription-only a segment of DNA and only one of the strands is copied into RNA .

302
Q

Defining the boundaries is necessary to demarcate the region and the strand of DNA in transcription/replication .

A

Transcription

303
Q

Similarity btw transcription and replication .

A

Complementarity governs both processes

But in transcription , adenosine forms bp with uracil

304
Q

Why both the strands are not copied during transcription -

A

1) if both strands act as template , they would code for RNA molecule with diff sequences , and in turn if they code for proteins , the sequence of amino acids in the proteins would be diff .
Hence, one segment of DNA would be coding for 2 diff proteins , complicating the genetic info .
2) the 2 RNA molecules if produced simultaneously would be complementary to each other , hence would form a DOUBLE STRANDED RNA . This would prevent RNA from being translated into proteins and the exercise of transcription would become futile .

305
Q

What would happen if the 2 RNA’s are produced simultaneously ?

A

They would be complementary to each other , hence forming double stranded RNA . This would prevent RNA from being translated into proteins , thus the whole process of transcription would become futile .

306
Q

A transcription unit in DNA is defined primarily by the 3 regions in the DNA :

A

A promoter
The structural gene
A terminator

307
Q

The strand that has polarity __Acts as the template , and is also referred to as template strand .

A

3’—>5’

308
Q

The strand which has polarity ___ coding strand .

A

5’—>3’

309
Q

Why is there a convection in defining the 2 strands of DNA ?

A

Since the 2 strands have opposite polarity and the DNA -dependent RNA polymerase also catalyses polymerisation in only one direction , ie. 5’—> 3’ , one strand acts as template and the one with opposite polarity acts as coding .

310
Q

The DNA dependent RNA polymerase catalyses polymerisation in ___ direction .

A

Only 1

5’—>3’

311
Q

Which strand has the sequence same as RNA (except thymine at the place of uracil ) ?

A

Coding

312
Q

Which strand is displaced during transcription ?

A

Coding

313
Q

The strand which does not code for anything is called -

A

Coding strand

314
Q

All the reference point while defining a transcription unit is made with ___ .

A

Coding strand

315
Q

The ____and____flank the structural gene in a transcription unit .

A

Promoter

Terminator

316
Q

The promoter is said to be located towards the __End of the ___gene . ( wrt coding strand )

A

5’ - upstream

Structural gene

317
Q

It is the ___that provides binding site for RNA polymerase and it is the presence of a ____ in a transcription unit that also defines the template and coding strands .

A

DNA sequence

Promoter

318
Q

By switching the position of ____with ____ , the definition of coding and template strands could be reversed .

A

Promoter

Terminator

319
Q

The terminator is located towards the __end of the coding strand and it usually defines the ____ of the process of transcription .

A

3’ end -downstream

End

320
Q

The ____ is located upstream and____downstream of the coding strand .

A

Promoter

Terminator

321
Q

There are additional regulatory that may be present further upstream and downstream to the _____.

A

Promoter

322
Q

____postulated the presence of an adapter molecule that would on one hand read the code and on the other hand would bind to specific amino acids .

A

Francis crick

323
Q

The _____ was known before the genetic code was postulated .

A

TRNA ( sRNA - soluble RNA)

324
Q

TRNA was known much before the genetic code was postulated but its role as an _____ was assigned much later .

A

Adapter molecule

325
Q

TRNA has an _____ that has bases complementary to the code .

A

Anticodon loop

326
Q

TRNA also has an _____ to which it binds to amino acids .

A

Amino acid acceptor end

327
Q

TRNAs are __for each amino acid .

A

Specific

328
Q

For initiation , there is another specific tRNA known as ____ .

A

Initiator tRNA

329
Q

There are no tRNAs for _____ .

A

Stop codons

330
Q

The secondary structure of tRNA looks like __

A

Clover leaf model

331
Q

In actual structure , tRNA is a compact molecule and looks like ___.

A

Inverted L

332
Q

Parts of tRNA -

A

Anticodon loop

Amino acid acceptor end

333
Q

Translation refers to the process of ___of amino acids to form a ____ .

A

Polymerisation

Polypeptide

334
Q

The order and sequence of amino acids are defined by the ____ .

A

Sequence of bases in the mRNA

335
Q

The amino acids are joined by __bond .

A

Peptide

336
Q

Process of peptide bond formation req ___.

A

Energy

337
Q

What happens in the 1st phase of translation ?

A

Charging of tRNA /aminoacylation of tRNA

338
Q

What is charging / AMINOACYLATION of tRNA ?

A

The activation of amino acids in the presence of ATP and linking to their cognate tRNA .

339
Q

If 2 __are brought close enough , the formation of peptide bond btw them would be favoured ENERGETICALLY .

A

Charged tRNAs

340
Q

The presence of ____would enhance the rate of peptide bond formation .

A

Catalyst

341
Q

Th cellular factory responsible for synthesizing proteins is the -

A

Ribosome

342
Q

The ribosome consists of ___ and ____ .

A

Structural RNAs

80 diff proteins

343
Q

The ribosome consists of __ proteins .

A

80 diff types

344
Q

In its __state , Ribosome exists as 2 subunits.

A

Inactive

345
Q

When the __ encounters __ , the process of translation begins .

A

Small subunit of ribosome

An m-RNA

346
Q

When the _____ subunit encounters an mRNA ,the process of translation begins .

A

Small

347
Q

There are ___ sites in the ___ subunit ( of ribosome )for subsequent amino acids to bind to and thus be close enough to each other for the formation of peptide bond.

A

2

348
Q

The ______ also acts as a catalyst for the formation of peptide bond .

A

Ribosome

349
Q

_____ in BACTERIA is the enzyme - ______ for the formation of peptide bond .

A

23S rRNA

Ribozyme

350
Q

A translation unit in mRNA is the sequence of ___ that is flanked by the ___ and ____ and codes for a polypeptide .

A

RNA
Start codon -AUG
Stop codon

351
Q

An mRNA also has some additional sequences that are not translated and are referred as ______.

A

Untranslated regions (UTRs)

352
Q

UTRs are additional sequences in the ____.

A

MRNA

353
Q

The UTRs are present at ____ end .

A

Both ends of mRNA
5’end-before start codon
3’end-after stop codon

354
Q

____are required fo efficient translation process .

A

UTRs

355
Q

For initiation , the ribosome binds to the mRNA at the ____codon that is recognised only by the ______ .

A

Start codon

Initiator tRNA

356
Q

when the ribosome proceeds to the elongation phase of protein synthesis , what happens ?

A

Complexes composed of an amino acid linked to tRNA , sequentially bind to the appropriate codon in mRNA by forming complementary base pairs with the tRNA anticodon .

357
Q

The ____move from codon to codon along mRNA during translation .

A

Ribosome

358
Q

At the end of translation , ____binds to _____ , terminating translation and releasing the complete polypeptide form the ribosome .

A

A release factor

Stop codon

359
Q

Gene expression can be regulated at ____levels .

A

Several

360
Q

In eukaryotes , the regulation could be exerted at -

A

1) transcriptional level ( formation of prim transcript )
2) processing level ( regulation of splicing )
3) transport of mRNA from nucleus to the cytoplasm
4) translational level

361
Q

The ___ in a cell are expressed to perform a particular function or a set of functions .

A

Genes

362
Q

If an enzyme called __ is synthesised by E.coli , it is used to catalyse _____ .

A

Hydrolysis of a disaccharide -lactose into galactose and glucose

363
Q

The bacteria use _____as a source of energy .

A

Lactose

364
Q

It is the _____,____or ____ conditions that regulate the expression of genes .

A

Metabolic
Physiological
Environmental

365
Q

In a transcription unit , the activity of ____ at a given promoter is in turn regulated by interaction with ____ .

A

RNA polymerase

Accessory pigments

366
Q

The regulatory proteins can act both ______and ______ .

A

Positively (activators )

Negatively ( repressors )

367
Q

The accessibility of promoter regions of prokaryotic DNA is in many cases regulated by the ____ termed _____ .

A

Interaction of proteins with sequences

Operators

368
Q

The operator region is adjacent to the ___ in most operons and in most cases , the sequences of the ___ bind a ___ .

A

Promoter
Operator
Repressor protein

369
Q

Each operon has its specific ____and ____ .

A

Operator

Repressor

370
Q

___ is present only in lac operon and it interacts specifically with ____ only

A

Lac operator

Lac repressor

371
Q

The elucidation of the lac operon was also a result of a close association btw a ___ - _____ and ____ - ______.

A

Geneticist - Francois jacob

Biochemist -Jacques monad

372
Q

Jacob and monad were the first to elucidate a _______ system .

A

Transcriptionally regulated

373
Q

In lac operon , lac refers to ____.

A

Lactose

374
Q

In lac operon , a _____ gene is regulated by a COMMON promoter and regulator genes .

A

Polycistronic structural

375
Q

Lac operon is very common in __.

A

Bacteria

376
Q

Name a few operons -

A 
Lac operon 
Trp operon 
Ara operon 
His operon 
Val operon
377
Q

The lac operon consists of -

A

1 regulatory gene - i gene

3 structural genes

378
Q

The i gene in lac refers to -

A

Inhibitor ( not inducer )

379
Q

The 3 structural genes are -

A

Z
Y
A

380
Q

The i gene codes for the ___ .

A

Repressor of lac operon

381
Q

The z gene codes for _____ , which is primarily responsible for _____ .

A

Beta -galactosidase ( beta-gal )

Hydrolysis of the disaccharide - lactose into its monomeric units -galactose and glucose

382
Q

The y-gene codes for _____ .

A

Permease

383
Q

Function of permease -

A

Inc permeability of the cell to beta -galactosidase

384
Q

The a-gene codes for ____ .

A

Transacetylase

385
Q

All the 3 gene products in lac are req for the metabolism of ____ .

A

Lactose

386
Q

Lactose is the substrate for the enzyme ____ .

A

Beta -galactosidase

387
Q

__regulates switching on and off of the operon .

A

Lactose

388
Q

Lactose is termed as the _____ in lac operon .

A

Inducer

389
Q

Preferred carbon source for lac operon -

A

Glucose

390
Q

How is lactose transported into the cells in the absence of the preffered C source -

A

In the absence of C , if lactose is provided in the growth medium of the bacteria , the lactose is transported to the cels through the action of permease .

391
Q

A very low level of expression of ___ has to be present in the cell all the time , otherwise lactose cannot enter the cells .

A

Lac operon

392
Q

The __of the operon is synthesised all the time -constitutively from the __gene .

A

Repressor

i-gene

393
Q

The ___protein binds to the operator region of the operon and prevents ____ from transcribing the operon .

A

Repressor

RNA polymerase

394
Q

In the presence of _______ , such as ____and ____ , the repressor is inactivated by interaction with the inducer .

A

Inducer
Lactose
Allolactose

395
Q

In the presence of an inducer , RNA polymerase has access to the ___ and transcription proceeds .

A

Promoter

396
Q

____or ____cannot act as inducers for lac operon .

A

Glucose

Galactose

397
Q

Regulation of lac operon by ____ is referred to as negative regulation .

A

Repressors

398
Q

Human genome project was launched in the year ____ .

A

1990

399
Q

HGP was called a _____ .

A

Mega project

400
Q

HGP was closely associated with the rapid development of a new area in biology called ______ .

A

Bioinformatics

401
Q

Human Genome is said to have ____bp and if the cost of sequencing req is ___ per bp, the total estimated cost would be approx ____ US dollars .

A

3*10_9 bp
US $ 3 per bp
9 billion US dollars

402
Q

One of the goals of HGP is to identify all the approx _____ genes in human DNA .

A

20,000 -25,000 genes

403
Q

Imp goal of HGP is to determine the sequence of ____ chemical bp that make up human DNA .

A

3 billion

404
Q

Imp goals of HGP are to -

A

1) identify all the approx 20,000 -25,000 genes in human DNA .
2) determine the sequence of the 3 billion bp hat make up human DNA
3) store this info in databases .
4) improve tools for data analysis
5) transfer related technologies to other sectors such as industries .
6) address the ETHICAL , LEGAL and SOCIAL issues ( ELSI ) that may arise from the project .

405
Q

The HGP was a _____ year project coordinated by the ____ .

A

13 year

U.S Department of Energy And the National Institute of Health

406
Q

During the early years of HGP , the ____ became a major partner . Additional contributions came from ____, _____ ,____ and _____ .

A 
Welcome Trust ( UK )
Japan
France 
Germany 
China
407
Q

HGP was completed in _____ .

A

2003

408
Q

Name some non-human model organisms , that have been sequenced -

A 
Bacteria 
Yeast 
Caenorhabditis elegans 
Drosophila (fruit fly )
Plants ( rice and Arabidopsis )
409
Q

Caenorhabditis elegans is a _____ nematode that has been sequenced .

A

Free-living NON - PATHOGENIC nematode

410
Q

Name 2 plants that have been sequenced?

A

Rice

Arabidopsis

411
Q

What are the 2 major approaches in the method of HGP ?

A

1) identifying all the genes that are expressed as RNA ( referred to as ESTs - Expressed Sequence Tags )
2) blind approach of simply sequencing the whole set of genome that contained all the coding and non-coding sequence , and later assigning diff regions in the sequence with functions - referred to as SEQUENCE ANNOTATION )

412
Q

The commonly used hosts for cloning in HGP -

A

Bacteria and yeast

413
Q

The vectors used for cloning -

A

BAC -bacterial artificial chromosome

YAC -yeast artificial chromosome

414
Q

The fragments were sequenced using automated DNA sequencers that worked on the principle of a method developed by -

A

Fredrick Sanger

415
Q

Sanger is credited for which 2 things -

A

1) sequencing DNA fragments

2) developing method for the determination amino acid sequence in proteins .

416
Q

The sequenced DNA fragments were arranged based on some ______ present in them .

A

Overlapping regions

417
Q

Specialized computer based programmers were developed for -

A

Alignment of the sequences of DNA

418
Q

the sequence of ________ was completed only in may 2006 .

A

Chromosome 1

419
Q

___was the last of the 24 human chromosomes - 22 autosomes and X and Y to be sequnced .

A

Chromosome 1

420
Q

Genetic and physical maps were assigned on the genome using info on ____and some ____ .

A

Polymorphism of restriction endonuclease recognition sites

Repetitive DNA sequences known as MICROSATELLITES .

421
Q

REPETITIVE DNA sequences were known as ______ .

A

MICROSATELLITES

422
Q

Some of the salient observations drawn from HGP are -

A

1) human genome contains 3164.7 million bp .
2) the avg gene consists of 3000 bp but sizes vary greatly
3) the total number of genes is estimated at 30,000 -much over the previous estimates of 80,000 to 1,40,000 genes .
4) the functions are unknown for over 50% of the discovered genes
5) less than 2% of the genome codes for protein .
6) repeated sequnces make up very large portion of the human genome .
7) chromosome 1 has most genes- 2968 and Y has the fewest -231
8) scientists have identified about 1.4 million locations where single base differences ( SNPs ) occur in humans .

423
Q

The human genome contains ___ bp.

A

3164.7 million bp

424
Q

The average gene consists of ___bases , but sizes vary greatly , with the largest gene being ___.

A

3000 bases

Dystrophin

425
Q

Dystrophin gene-largest has ___ bases .

A

2.4 million bases

426
Q

The total number of genes is estimated at ___ - much lower than previous estimates of ___ to ____ genes .

A

30,000

80,000-1,40,000

427
Q

Almost ___ nucleotide bases are exactly the same in all people.

A

All ( 99.9%)

428
Q

The functions are know for over ___ of the discovered genes .

A

50%

429
Q

_____ % of the genome codes for proteins .

A

Less than 2 %

430
Q

___make up a very large portion of the human genome .

A

Repeated sequnces

431
Q

__are stretches of DNA sequences that are repeated many times ,sometimes hundred to thousand times .

A

Repetitive sequences

432
Q

Function of repetitive sequences -

A

No direct coding functions , but they shed light on CHROMOSOME STRUCTURE , DYNAMICS and EVOLUTION .

433
Q

___has most genes . How many ?

A

Chromosome 1

2968

434
Q

___has the fewest genes . How many ?

A

Y chromosome

231

435
Q

Scientists have identified about ___ locations where single base DNA diff occur in humans .

A

1.4 million

436
Q

Full form of SNPs

A

Single nucleotide polymorphism

Occur at 1.4 million locations

437
Q

DNA fingerprinting involves identifying diff in some specific regions in DNA sequence called as ____ . Why ?

A

Repetitive DNA ( becoz in these , a small stretch of DNA is repeated many times )

438
Q

The repetitive DNA are separated from bulk genomic DNA as diff peaks during density gradient config . The ___forms the major peak and the other small peaks are referred to as ____ .

A

Bulk DNA

Satellite DNA

439
Q

Depending on _____ , ____ and ____ , the satellite DNA is classified into many categories ,such as MICRO-SATELLITES and MINI-SATELLITES .

A

Base composition ( A:T rich or G:C rich )
Length of segment
Number of repetitive units

440
Q

Repetitive DNA sequences show ___ and form the basis of __ .

A

High degree of polymorphism

DNA fingerprinting

441
Q

Polymorphism ( variation at __level) arises due to ____ .

A

Genetic level

Mutations

442
Q

_____ variation has traditionally been described as a DNA polymorphism if more than one variant (allele ) at a locus occurs in human population with a freq greater than ___ .

A

Allele sequence

0.01

443
Q

If an ___is observed in a population at HIGH FREQ ,it is referred to as DNA polymorphism .

A

Inheritable mutation

444
Q

The probability of allele sequence variation ( inheritable mutation ) is observed in ____ sequence would be HIGHER as mutations in these sequences may not have an immediate effect / impact in an individual’s REPRODUCTIVE CAPABILITY .

A

Non-coding DNA sequence

445
Q

The technique of DNA fingerprinting was initially developed by _____ .

A

Alec jefferys

446
Q

Alec Jefferys used a____as probe that shows very HIGH DEGREE OF POLYMORPHISM .

A

Satellite DNA

447
Q

The satellite DNA was called as _____ .

A

VNTR (variable number of tandem repeats )

448
Q

DNA fingerprinting involves ____ hybridization using ___ as probe .

A

Southern blotting

Radiolablled VNTR

449
Q

The process of DNA fingerprinting is -

A

1) isolation of DNA
2) digestion of DNA by restriction endonucleases
3) separation of DNA fragments by electrophoresis
4) transferring ( blotting ) of separated DNA fragments to synthetic membranes ,such as NITROCELLULOSE or NYLON
5) hybridization using labeled VNTR probes
6) detection of hybridised DNA fragments by AUTORADIOGRAPH .

450
Q

A VNTR belongs to a class of satellite DNA called ____

A

Mini-satellites

451
Q

What does mini satellites mean -

A

A small DNA sequence is arranged tandemly in many copy numbers .the copy numbers vary from chromosome to chromosome in an indivisual .

452
Q

The number of repeats show very high degree of polymorphism . As a result the size of VNTR varies in size from __ to ____ kB .

A

0.1. To 20 kB

453
Q

After hybridization with VNTR probe , the ___ gives many bands of differing sizes

A

Autoradiogram

454
Q

Pattern of DNA differs from individual to individual in a population except in the case of __.

A

Monozygotic twins 👯‍♀️

455
Q

The sensitivity of DNA fingerprinting has been increased by use of _____.

A

PCR

Genetics (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions