Q – Describe
Mendel’s law of independent assortment with the help of a suitable example?
Ans – Whenever
two or more pairs of contrasting character are brought to gather in a hybrid
the alleles of the different pairs segregate independently of one another during
gamete formation.
Ex – Dihybrid
cross – 9:3:3:1 ratio obtain
Q – Clarify the
difference between transcription and reverse transcription of DNA?
Ans –
Transcription is the process in which RNA is synthesized from DNA it takes
place in nucleus;
There are
following steps –
1. First unbinding of particular genomic sequence takes place by the
action of RNA-polymerase enzyme.
2. Now one strand of DNA acts as Template for RNA synthesis, that’s way
known as sense strand and other known as nonsense strand.
3. In this process RNA polymerase enzyme takes place named as RNA
polymerase I, II, IIIrd
4. Later on RNA molecule separates from sense strand to form RNA
strand always synthesized in 5 to 3 direction.
Reverse
Transcription –
In this process
we can synthesis cDNA from mRNA. This phenomenon occurs in the presence of
reverse transcriptase enzyme on RNA directed DNA polymer race. The enzyme was
discovered by H.Temin & Dr. Baltimore in 1970. The cDNA molecule become
double stranded and are used for cloning and preparation multiple copies in
this way -
|
Reverse trans. enz mRNA
|
|
Alkali treatm
|
mRNA removed
|
DNA polymer
|
Double stranded DNA
Q - Describe the role of vectors in the process
of gene transfer?
In genetic
engineering process the role of vector in process of gene transfer is very
important it carry plasmid and introduced into DNA for getting desired sequence
of DNA for getting desired sequence of DNA and multiple copies of DNA also
because able to replicate autonomously.
Q – Does the law
of Segregation hold same in both homozygous and heterozygous?
Ans – Monohybrid
cross (homozygous) are those in which inheritance of one pair of characters is
occurred.
For Ex – When
tall plants (TT) are crosses with dwarf(tt) plants, in F1 generation only
hybrid tall plants (Tt) are formed in in F2 generation these hybrid tall plant
are self crossed to form 3 tall and one dwarf plants.
In dihybrid
cross, inheritance of two pairs of characters is occurred.
The law of
independent assortment is applicable to the inheritance of two more pairs of
characters. It states that contrasting pairs assort independently i.e. the
segregation of alleles of a pair is not influenced by the presence of other
gene pair.
It shows that
segregation of alleles of a pair is not influences by presence of other gene
pairs.
Q – Explain
briefly the structure, function and origin of chromoplasts?
Ans –
Chromoplasts are plastids responsible for pigment synthesis and storage.
They
like all other plastids (including chloroplasts and leucoplasts), are organelles
found in specific photosynthetic eukaryotic species, some times these coloured
pigments are present in vascular sap as in petals. They provide resistance to
plant against thermal fluctuations.
The
photosynthetically active chromoplast include chloroplasts, pheoplasts,
rhodoplasts, blue green chloroplasts and chromatophores of photosynthetic
bacteria.
Chloroplast – it
is in green colour. It contains chlorophyll pigments, It is found in higher
plants and green algae.
Phaeoplast – It
is dark brown in colour. It contains Fucoxam thin pigments. It is found in
brown algae, diatoms and dino flagelates.
Rhodoplasts – it
is red in colour. It contains phycoerythrin. It is found in red algae.
The idea for
recombinant DNA was first proposed by Peter Lobban, a graduate student of prof.
Dale Kaiser in the biochemistry Department of Stanford University Medical
School.
Q – Explain the
structure and functions of start codons and stop codons in protein synthesis?
Start Codons:
Start codons are also known as initiating codon, which initiates the synthesis of
polypeptides chains in cytoplasmic region. These are AUG, GUG, AUG codons
Methionine amino acid while GUG codes valine. In prokaryotes AUG specify the
N-formyl Mehionine while in eukaryotes AUG specify the methionine amino acid
which is starting amino acid in polypeptides chain synthesis.
Stop Codons:
Stop Codons are also called terminating codons or stop signal. They break the
polypeptide chain synthesis. These are UAA, UAG, UGA. These codons are also
termed as ochre, amber and opal respectively as these codons don’t specify any
amino acids.
Q – Write the names and places of any four prominent research centres of biotechnology?
Ans –
1. Indian Agriculture Research Institute (I.A.R.I), New Delhi.
2. National Bureau of plant Genetics Resources (N.B.P.G.R) New Delhi.
3. Central Drug Research Institute (C.D.R.I)
4. Rajiv Gandhi Centre for Biotechnology (R.G.C.B.) Kerala.
5. National Research Centre on Plant Biotechnology (N.R.C.P.B) New Delhi.
Q – Explain the
role of biotechnology in the production of vaccines?
Ans –
Biotechnology serves the easy way for production of various vaccines, vaccines
are those chemical substances prepared from proteins (antigen) of other animals
which provide immunity to a particular virus. Some of the vaccines are
synthesized biologically through genetic engineering process.
Vaccines of
Hepatitis B
Vaccines for
Rabies Virus
Vaccines for
Foot and Mouth Disease
Vaccines for
Small Pox Virus
Malaria Vaccines
Q – Write a note
on micropropagation?
Ans –
Micropropagation is a art and science of the plant multiplication in vitro.
This process includes many steps stock plant care, explants selection and
sterilization, media manipulation to obtain proliferation, rooting, acclimation
and growing on of liners.
Micropropagation is broadly used in many countries
for obtaining germ free plants, but this technique is more costly.
Merits of
Micropropagation
1. Tissue culture helps in rapid multiplication of true plants, through
out year.
2. Plant raised by tissue culture are free from disease.
3. Tissue culture methods are not viable or not available easily (eg.
banana) and in plant where propagating by conventional methods are expensive
eg. Orchid
Micropropagation
techniques require skills and Manpower –
A. The seedling grown under artificial condition may not survive when
place environment condition directly if this is not given.
Q – Write the
names of three types of polyploid and cite one example with each other?
·
Autopolyploidy – The example of
autopolyploidy is ‘doob’ grass (cynodon dactylon)
·
Allopolyploidy – Example of
allopolyploidy is Raphanobrassica
·
Segmental Allopolyploids – The
example of this polyploidy is hexaploid bread wheat.
Q – Giving
suitable sketches describes the morphology and ultrastructure of chromosomes?
Ans – A
chromosomes is an organised structure of DNA & protein that is found in
nucleus of the cell. It is a single piece of coiled DNA containing many genes,
regulatory elements and other nucleotides sequences chromosomes also contain
DNA bound proteins, which serve to package the DNA and control its function.
Morphology –
They are straight,
rod like coiled or thread like chromosome has uniform thickness through out its
length, some chromosomes have like additional structure known as satellites,
chromosomes are approximately to 30µ long and 0.2µ - 0.3µ thick, long
chromosomes are found Trillium.
They
consists of following parts –
I.
pellicle
II. Matrix
III. Chromonema
IV. chromomere
V.
centromere
VI. secondary constriction
VII. satellite
VIII. telomere
Matrix –
Base liquid of chromosomes which is inclosed by pellicle, is called matrix. It
is made up of homogenous chromatic matter.
Chromatid
– Each Metaphase chromosome consist of two symmetrical strands called
chromatid, each chromatid is half of chromosomes, chromatids are attached other
by centromere.
Chromonema
– Chromosomes appear as very thin filaments during mitotic prophase. these are
called as chromonema or chromonemata. These are present in coiled and twisted
form in a chromatid during all stages of Mitosis genes are located on this
structure. Chromatids may contain one or more chromonema.
Chromomers
– In prophase stage, each chromonema contains some raised granular structures
through out its length at particular distance, which are term as chromomere.
Centromere
– Specific regions in chromosomes where chromatids are link each other are
called centromere. The position of centromere is constant for a particular
chromosomes. Centromere has an important role in nuclear division as it holds
up both the chromatids and keeps the spindle bounds. Four categories of
chromosomes are recognise depending on the position of the centromere. These are
called acentric, metacentric, submetacentric, acrocentric, telocentric
chromosomes.
1.
Acentric - Centromere is absent in acentric chromosomes.
2.
Metacentric – Centromere is situated
in the centre of middle part of chromosome and has two equal arms. At the time
of division it appears V structure.
3.
Sub Metacentric – The Centromere is
situated in the centre of middle part of chromosome and has two unequal arms
resembling L-shape at the time of division.
4.
Acrocentric – The centromere is sub
terminal and chromosomes appear rod, like having and small arm and the very
long.
5.
Telocentric – the centromere is at the
tip of the chromosomes and the chromosomes appear rod-shaped.
Secondary
Constriction – In addition to the primary constriction or centromere the arms
of the chromosomes mayy show one or more secondary constriction. These
constrictions are different from nuclear organizer although some cytologists
also refer to the nuclear organizer as the secondary constriction.
Satellite
– Terminal part of secondary constriction in a chromosome is called satellite.
It is spherical, long or knob-like. The chromosomes with the satellite are
designate/called SAT chromosomes.
Telomere –
The tips or end of the chromosome are called telomere. The telomere differ in
structure and composition from the rest of the chromosome.
Q –
Difference between spontaneous and induced mutations. Describe the methods of
detecting the presence of mutation?
Ans –
Spontaneous Mutation –
Some
Mutations arise as natural errors in DNA replication (or as a result of cm
known Chemical reactions) these are known as spontaneous mutations, The rates
of such mutations have been determine for many species E.coli has a
spontaneous mutation rate of 1/108 (one error in every 108 nucleotides
replicated).
Humans
have higher mutation rate between 1/106
and 1/105 (probably as a result of the higher
complexity of human replication).
Induced
Mutation – Mutations which artificially induced are called Induced Mutation, it
can be influenced by Radiation, α,β particles ν rays, UV rays and chemical
mutagens, like Ethyl ethane sulphonate, Ethyl Methy sulphonate, Nitro methyl
urea, dimethyl sulphate, nitrous acid, hydroxil amine. Induced mutations have
played important role in Agriculture.
Q – Describe the
structure, biogenesis and functions of the Ribosomes?
Ans –
Introduction
Ribosomes are
the protein builders or the protein synthesizers of the cell Ribosomes are
found in many places around the cell. Ribosomes are also keeps attach to
endoplasmic reticulum that make rough appears under microscope. With the help
of microscope it has been found that ribosomes are two types. e.g. 70s
ribosomes and 80s ribosomes are found in prokaryotes and 80s ribosomes found in
eukaryotes.
Prokaryotic
ribosomes (Bacterial ribosomes) are 70s ribosomes that have 50s large subunit
of and 30s small subunits, the small subunit is composed of a 16s ribosomal RNA
and 21 ribosomal proteins, while the large unit is composed of 23s ribosomal
RNA and 33 ribosomal proteins the small subunit mainly takes cares of the
association with messenger RNA during the start of translation and decoding
which resolves 3-nt codon that decides which amino acids to insert to the
polypeptide chain.
Structure of
Ribosomes –
With the help of
microscope it has been found that ribosomes are prokaryotic ribosomes and
eukaryotic ribosomes, prokaryotic ribosomes and eukaryotic ribosomes,
prokaryotic ribosomes composed 70S, subunits which have 30 small and 50 large
sub units and eukaryotic ribosomes composed 80S subunits which have 60S large
subunits and 40S small subunits.
Prokaryotic
Ribosomes partially divided by prokaryotic Ribosomes partially divided by two
lobes by a deep cleft, the two sub units are fitted to each other as a way a
tunnel is formed between them, The small sub units is composed of a 16S
ribosomal-RNA and 21-ribosomal proteins, while the large sub units is composed
by 23S ribosomes and 33 ribosomal proteins.
Biogenesis of
ribosomes –
In bacterial
cells, ribosomes are synthesized in cytoplasm through the transcription of
multiple ribosomes gene operons. In eukaryotes the process takes place both
cell cytoplasm and nucleolus, which is the, a region with in the cell nucleus.
The assemble process involves the coordinated function of over 200 proteins in
the synthesis and processing of the four
rRNA with the Ribosomal proteins.
Function of
Ribosomes –
The primary
function of Ribosomes is protein synthesis according to the sequence of amino
acids as specified in the m-RNA. “The main functions of ribosomes, they play
the role of assembling amino acids to form specific proteins, which in turn are
essential for carrying out the cell’s activities (as well as all have fair idea
regarding productions of proteins, the deoxyribonucleic acid (DNA) first
produces RNA (messenger RNA or m-RNA by the process of DNA transcription after
which genetic message from the m-RNA in translated into proteins during DNA
translation.
RNA – During
protein synthesis, the genetic code is used to translate the sequence of
nucleotide in mRNA into the sequences as protein.
Q – What are the
Transgenic plants? Describe their achievements and significance?
Ans – Through
the genetic engineering process the entering of a particular foreign gene and
introduced into other is known as Genetically modified organism or plant OR
A
biotechnological process in which transfer of foreign gene into a plant cell
with the help of genetic engineering is known as Genetically modified organism
or plant. transgenciplant are unique in that they develop only one plant cell
in normal sexual reproduction. Plant offspring is produce whenn a pollen cell
and ovule fuse .
OR
OR
A Genetic
engineering process in which a functional foreign gene has incorporated that
genetically not present in plat ae called transgenic plat, scientists are
trying to develop new varieties as plant for commercial purpose and high crop
yield advantage for economic purpose.
Achievement –
There are many achievement in the field of agriculture as well as animal.
1.
Improved Nutritional Quality :
Milled rice is the staple food for a large fraction of the world’s human
population.
2.
Insect Resistance : Bacillus
thuringiensis is a bacterium that is pathogenic for a number of insect pets.
3.
Disease Resistance : Genes
that provide resistance against plant viruses have been successfully introduced
into such crop plant as tobacco, tomatoes, and potatoes.
4.
Herbicide Resistance : Genes
for resistance to some of the newer herbicides have been introduced into the
some crops plants and enable them to thrive even when exposed to the weed
killer.
5.
Terminator genes : this term is
used (by opponents of the practice) for transgenes introduce into crop plant to
make them produce sterile seeds (and thus force the former to by fresh seeds
for the following season rather than saving seeds from the current crop).
The significance
of transgenic plant is much in thhe field of agriculture, any many developing
country are
discovering new
traits of the particular plant for human warfare.
Q – Describe
peroxisomes (microbodies) –
Ans-
Peroxisomes are
membrane bounded organelle that appears in the most eukaryotic organelle that
appears in most eukaryotic cells, They have often a crystalline structure with
in the amorphous gray matrix. There are animals in which other kind of
inclusions may exist or even in which there are no inclusions at all.
Peroxisomes are
self replicating in mammals and other vertebrates they are particularly large
and abundant in hepatocytes and cells of the tubular portions of Nephrons
(namily in epithelial cells of the proximal tubules) peroxisomes were
discovered in 1954 and there function was virtually unknown for over a decade,
today they are known to be essential in many vital pathways such as –
·
Metabolism of free oxygen
radicals.
·
Synthesis of cholesterol and
ether lipids.
·
Catabolism of long chain fatty
acids.
·
Catabolisms of proteins,
prostaglandins.
·
Alcohol detoxification in liver.
·
Metabolism of estradiol (more
recently provides and our currently reach topic)
Some Interesting
facts about peroxisomes are :-
·
Human congenital disease are
associated with the absence of peroxisomes and/or with the disfunction of their
enzyme.
·
Many chemicals (drugs industrial
pollutants) induce a marked proliferation of peroxisomes.
·
Prolonged treatment with most
proliferator induce malignant hepatic tumor.
·
Estradiol seems to have
depressive effect on peroxisomes (at least in fresh hepatocytes).
Q – Thylakoid?
Ans – A Thylakoid
is a membrane bound compartment inside chloroplast and cyanobacteria. They are
the site of the light dependent reactions of photosynthesis. The word
“Thylakoid” is drive from the Greek thylakoids means “Sac” thylakoids consist of
a Thylakoid membrane surrounding a thylakoid lumen. Chloroplast thylakoid
frequently forms stacks of disks referred to as “grana” (singular granum)
“Grana is latin word for “Stocks of coins” grana are connected by intergrana or
stroma thylakoids, which join granum stacks together as a single functional
compartment.
Q – Cell
Chromatic?
Chromatin is a
complex combination of DNA and protein that makes chromosomes it is found inside
the nuclei of eukaryotic cell. The major component of chromatin are DNA and
histones protein.
Cell chromatin
are also found in cytoplasm called mitochondrial genome or chloroplasts called
mitochondrial genome or chloroplastial genome. these are known as extra
chromosomal DNA. Chromatin contains genetic material instructions to direct
cell function.
Q – Colchicine.
A drug obtained
from the meadow saffro (calchium autumnnale), used to treatment to relieve pain
in attacks of gout and in the prevention of attacks of polyserositis.
Q – G.J. Mendel
?
Ans – Gregor
John Mendel is known as “Father of genetics” because of that he did research
on pisum sativum to know about herediatery, Mendel was born in 1822 at
Sicilian village of Heinzendorf. His father was a farmer and belond ordinary
family. After completing his early education mendal received graduate degree
from university and some days he taught physics in school inspire that mendal
had keen interest on plant & environment, mendal join a church as a
position of father and starting research on Pea plant for many years he
collected the traits of plants and after this phenomenon finish his work on
Pea, Mendal’s work on pea were published in Natural History Society of Brann inn
1865 but no body pay attention towards mendals notes, In 19th
century Three scientists rediscovered his rules on Genetics on different-2
places, After that Hugo-de-vries of Holland & Tschesmark of Austria and
correns of Germany recognise, and called his father of Genetics with respect
him. Mendal proposed following laws –
1. Law of Independent Assortment
2. Law of Segregation
3. Law of dominance
Q – M.S.
Swaminathan
M.S. Swaminathan
was born on August 7, 1925, in Kumbakonam, Tamil Nadu. His father passed away
when he was 11 years old. After his father death, he came close to his uncle, a
renowned scholar of Madra university. He earn Bachelor’s degree in Zoology as a
teenager, He was strongly influenced by Mahatma Gandhi’s ideals of non-violence
and belief in swadeshi (self-reliance). He enrolled in the Coimbatore
agriculture college in Tamil Nadu therefore he moved on to the Indian
Agriculture Research Institute (IARI) in New Delhi where he earn a post
graduate degree in Cytogenetics. He continued his studies at the Wageninger
Agricultuure University Institute of genetics in the Netherlands, before
earning his Phd degree from university of Cambridge. After his post doctoral
study at the university of Wisconsin, he declined the offer of full time
faculty position there and return to India in early 1954.
His professional
career began in 1949-1955, he under took research at potato, wheat, rice and
jute genetics after which he worked Mexican dwarf varieties. He establish the
national bureau of plants, Animal and Fish genetic resources of India and the
international plant genetic resources Institute besides serving as the
principle secretary in the ministry of Agriculture government of India.
He was awarded
the first world food prize in october 1987 and has been described by the United
Nations Environment programme as “the father of Economic Ecology” besides being
three Indians to be included in time magazine’s 1999 list of 20th
most influential asian people of the 20th century”. Along with
Mahatma gandhi and Rabindra nath tagore. He has many books to his credit. An
Evergreen Revolution, I predict a century of hope Towards an era of harmony
with Nature and Freedom from Hunger, gender Dimensions in biodiversity.
Management, Agrobiodiversity and farmers right, sustainable Agriculture towards
Food Security are some of his notable books.
Q – Z-DNA :-
Z-DNA is one of
the many possible double helical structure of DNA it is a left-handed double
helical structure in which the double helix winds to the left in a zig-zag
pattern (instead as to the right like the more common B-DNA form) Z-DNA is
thought to be one of three biologically active double helical structure along
with B-DNA & A-DNA.
Q – Transposons
–
Transposons are segment of DNA that can move around to different positions
in the genome of a single cell. In the process they may cause mutations, increase
(or decrease) the amount of DNA in the genome of the cell, and if the cell is
the precursor of a gamete, in the genomes of any descendant.
These mobile
segments of DNA are sometimes called “Jumping Genes”.
There are two
distinct types :-
Class II transposons
– These consist of DNA that moves directly from place to place.
Class I – These
are retrotransposons that, Ist transcribe the DNA into RNA and then
use reverse transcriptase to make a DNA copy of the RNA to insert in a new
location.
Q – Watson and
Crick
Francis crick
was a british molecular biologist, James D.Watson and Francis Crick, using
X-ray diffraction data collected by rosalind franklin and mauiric wilkins,
proposed double helix structure of DNA and confirmed the heredity nature of
DNA, following these discoveries, a lot of work done to understand the nature
of genetic code and particularly the types, structure and function of another
molecules that seems similar to DNA, which was called RNA or the ribonucleic
acid, until 1968. Francis crick and Lesile orgel proposed that the first
information molecules was RNA since then numerous studies have been gone in
this field exploring its function, nature.
Q – What is
totipotency?
Morgon coined
totipotency, it is the capacity of cell to develop into an organism by
regeneration. Each living cell of a multicellular organism, is capable of
independent development, when provide a suitable condition this concept is
important in Tissue culture because use of multicellular organism in research,
as biological unit is rather difficult.
Q – DNA
Fingerprinting ?
DNA finger
printing is a way of identifying a specific individual rather than simply
identify a species or some particular trait. It is also known as genetic finger
printing or DNA profiling. It was discovered by Sir, Alec Jeffry. DNA
fingerprinting it currently used both for identifying partenity or maternity
and for identifying criminals or victims.
Q - Write short
note on Caulimo Virus?
Caulimo Virus is
also called Cauliflower Mosaic Virus (CaMV) and responsible for the mosaic
disease in cauliflower, it is mechanically transmitted by simply rubbing on the
host leaf surface. Hence it is play an role in genetic engineering. It’s
genetic material is DNA so it is a ideal vehicle in genetic engineering. It
possess following properties –
1. It is infective but not deadly pathogenic.
2. CaMV may be incorporated into any structure possessing DNA.
3. It’s DNA is very small.
Q – Write an
eassay on “Genetic Engineering” and its role in human welfare?
Ans – The Hershey-Chase experiment –
For providing
that genetic material is not protein, Alfred Hershey and Martha chase (1952)
performed an experiment to prove genetic material is DNA or protein is known
blender experiment. They worked with virus tat infect bacteria that virus is
called bacteriophase, bacteriophage attach to the bacteria and enters his genetic material into the
bacterial cell. The bacterial cell treats the viral genetic material as if it
was its its own, and subsequently manufacture move virus particles. Hershy and
chase worked to discover whether it was protein or DNA from the virus that
entered into the bacteria, they grew some viruses on a medium that contained
Radio active sulphur and some other that contained radioactive phosphorous.
Virus grow in the
presence of radioactive phosphorous contained radioactive DNA but not radio
active protein because protein does not contain phosphorous. Similarly, virus
grown on radioactive protein, but not radio active DNA because DNA does not
contain sulphur, Radio active phages were allowed to attach to E.Coli bacteria,
Then as the infective proceeded, the viral coats were removed from the bacteria
by agitating them in a blender. The virus particle were separated from the
bacteria by Spinning them in a centrifuge.
Bacteria which
was infected by virus that had radioactive DNA were radio active, that
indicating DNA is a genetic material
that possess or transfer into bacteria from virus that had radioactive protein
were not radio active. This indicate that protein did not enter bacteria from
viruses, DNA is therefore genetic material that passed from virus to bacteria.
Q – Describe
concept of Gene?
W. Johanson
introduced the term ‘gene’ that acts as hereditary units. Gene has some
specific character e.g.
1.
it shows physiological
function.
2.
Transmission of Segregation of
character.
3.
Mutation
A Gene can be
defined as “a polynucleotide chain that consist of segments each are
responsible to control a particular trait, Now genes are considered as a unit
as function (cistron), a unit of mutation (mutan) and a unit of recombination
(recon).
Cistron is
defined by S. Benzer as a functional gene, one gene-one enzyme hypothesis of
Beadle and tatum was redefined by several workers in coming years. A single
mRNA is transcribed by a single gene. A single mRNA is also transcribed by more
than one gene & said to be polycistronic.
Recon – The
crossing over or recombination occurs with in a functional gene or cistron. In
a cistron recombinational unit is more than one thus the smallest unit capable
of undergoing recombination is known as recon.
Muton – Muton
may be defined as the smallest unit of DNA which may be changed in nucleotide.
Therefore cistron is largest unit is size followed by recon and muton, this can
be explained that a gene consist of several distron a cistron contains many
recon and recon number of muton.
Q – Autonomy of
chloroplast –
The existence of
DNA in chloroplast has been established by both cytological and biochemical
criteria. Ris and Dlauut (1962) provided the first convincing evidence
chloroplast contains DNA & RNA. The DNA is double stranded and circular
while ribosome are 70s types, presence of DNA, and RNA and ribosome in
chloroplast indicate that this is a semi autonomous cell organelle, because
there auto reproduction capacity is just like to living cell, but they
reproduce with in cell. due to presence of DNA & RNA and ribosome,
chloroplast itself synthesis its own protein and other material.
Q – Plasmid –
Plasmids are extrachromosomal DNA elements found mostly in bacteria plasmid
contain DNA sequences coding for drug resistance, sex factor (F factor) etc and
probably has arisen from chromosomal DNA. When bacterium multiply, the plasmid
DNA will also multiply along with chromosomal DNA, plasmids are relicons which
are stably inherited in an extrachromosomal state.
Properties of
plasmid cloning vehicles –
·
Plasmid are low molecular
weight.
·
Ability to confer readily
selectable phenotype traits on host cell.
·
Plasmid can reproduce itself
inside the bacterium independently of the main bacterial DNA.
Q – Transformation
Transformation
is a process by which transfer DNA from one cell to another cell takepart
without contact of any cell, to understand briefly the process of
transformation some scientist performed experiments. First time Griffith
performed series of experiment with streptococcus pneumonia. He grew some
bacteria on culture plate, he found some bacteria produced smooth shiny
colonies, this is because the S strain bacteria have a mucous (polysaccharide)
coat while R strain bacteria does not, he injected S strain bacterium in to
mice mice died, then he injected R-strain bacterium into mice mice alive. The
He heated S strain Bacterium and injected into mice along with R-strain
bacterium mice died, The he observed that anything is that which transfor later
Oswal Avery, a colin macleod and maclyn mccary (1933-44) showed that the
substance of responsible for transformation was DNA.
Q – Hargovind Khurana –
Dr. Hargobind
Khorana was born in Raipur, in Punjab, India in 1922, he received Bsc degree and
Msc degree from the punjab university in Lahore (now in pakistan) and his Phd
from the university of Liverpool, where he went in 1945 on government of
India fellowship. Dr. Khorant awarded by Nobel Prize for Medicine and
physiology along with Marshal Nirenberg and Robert Holley for cracking the
genetic code. Dr. Khorana and his team
had established the mother of all codes, the biological language common to all
living organism, is spelled out in three letters words, each set of three
nucleotides codes for a specific amino acid Dr. Khorana, was also the first to
synthesized oligonucleotides, that is string of nucleotides, These custom
desired pieces of artificial genes are widely used in Biology labs for
sequencing cloning and engineering new plants and animals.
Q – Split Genes
–
Split genes are
non coding genes, it is defined as a eukaryotic genes in which the coding
sequence is divided into two or more exons that are interrupt by a number of no
coding intervening sequence (introns) called split genes. Most higher level
eukaryotes have interrupted genes have longer introns than axons, creating a
gene that is longer than its coding regions. Exons, are the coding portion of
gene. The code for various parts of the protein that will be produced introns
are non doing, sequences. They do not code for any portions of the protein.
Q – Explants –
Explant is a piece of any plant tissue cells this piece or tissue are isolated
by the technique of Ex-plant culture or tissue culture to produce a new plant
for identify its properties, so it can be portion of shoot, leaves, or some
cells from a plant or can be any part of the tissue of animal because this
portion (Isolated tissue) has a capacity to develop whole organism.
Q – Somatic
hybrids –
A somatic hybrid is an animal or plant developed from a cell that is
fusion of the protoplasm of two somatic ells with desired characters. The
formation of somatic hybrids by protoplasmic fusion was first described by
Kulter (1909). He observed that when the protoplasts of two genetically distinct
plants grown together in a culture a somatic hybrid was formed by the fusion
between the plasma membranes and two cytoplasms.
1. Heterokaryotype – It refers to those somatic hybrid in which the
cytoplasm of the two parent fuse but their nuclei remain separate.
2. Sin Karyotype – it refers to those somatic hybrid in which the two
parental nuclei fused to each other produced a single nuclei with in the fused
cytoplasm.
3. cybrid – In this condition out of two parental nuclei, when one
nucleus completely disappears and only one nucleus remains in the cytoplasm,
the somatic hybrid is called cybrid.
Single Cell
protein – single cell protein refers to mixed protein. Microbes are being grown
on an industrial scale as source of good protein. Microbes like spirulina can
be grown easily on materials like waste water from potato processing plants
(containing starch), straw and molasses, animal manure and even sewage to
produce large quantities and can serve as food rich in protein, mineral, fats,
carbohydrates and vitamins. Incidentally such utilisation on also reduces
environmental pollution on also reduces environmental pollution.
Advantages –
1. SCP are low fat containing proteins, and proteins are of good
quality.
2. SCP can be produced whole year and their production does not depend
on climate.
3. Due to high growth rate of microbes SCP is obtained in huge quantity
from less area.
Biofertilization
–
Biofertilizer
play an important role in Agricultural area because Now a days a different
different types of chemical’s are using for maintain soil fertility to yield
high crop, but these chemical’s make a negative affect on soil and of course
They are high in cost. for the solution of this problem scientists suggested an
idea of use biofertilizers, biofertilizers means use of those organisms which
have ability to increase the fertility of soil. In the biofertilization process,
some active, bacteria fungi, blue green algae are used either or mixed form,
some nitrogen fixing bacteria can be used to maintain nitrogen demand of
agriculture they contain symbiotics non symbiotic bacteria.
Biofertilizers
for phosphate solubility – The main function of this group is to availabilities of soil. Phosphorus to plant, eg Pseudomonas Aspergillus and
fusarium etc and mycorrhizae is the chief biofertilizers of this class and
other hand several organic man was lie animal dung manures, green manures
concentrated manures like, Neem, cake, blood powder, fish manures, Poultry
manures and manures of its own unuseful crops parts and sugar factories sugar
can waste manure are also used as a biofertilizers. These fertilizers are also
contribute to increase the crop production on capacity of soil.
Q – Microbial
Fermentation –
Microbial
fermentation is a enzymatic decomposition and utilization of food stuffs,
particularly carbohydrates by microbes, In this process some microbes In this
process some microbes are used for production of foods and beverages such as
bear, butter, milk, cheese, vinegar, yogurt, liqour, and wine. Fermentation
involves the action of desirable microorganisms or their enzymes on food ingredients to make biochemical changes,
which cause significance modification to the food especially yeast have been
used from time immemorial for the production of beverages like wine, beer,
whisky, brandy or rum. Saccharomyces are visiae used for bread-making and
commonly called brewer’s yeast. Saccharomyces species may also used for the
fermenting malted cereals and fruit juices to produced ethanol molds also can
be active in certain fermentations, such as stillion cheese and soya sauce.
Q – Describe the
merits and demerits of the biochemical production of plant tissue culture?
Merits of
Biochemical production –
1. One of the most important merit of biochemical production of plant
tissue culture to save the atural plant populations from the danger of
extinction.
2. Continue supply of sufficient amount of biochemicals produced from
limited number of plants.
3. High rate of production of biochemical for example – cell culture of
L.erythrorhizon produces upto 20% shikonin,while its roots contain at 300
C and can obtain biochemicals on the bases of facilities.
Demerits of
Biochemical production –
1. High cost of production is the most important drawback of this
technique.
2. Path of synthesis of some biochemical are unknown. Thus the
improvement in their production is so much typical by cell culture method.
3. Generally cell cultures do not produced valuable compounds.
