Chapter – 9
Short
Question Answers – Biotechnology
Q.1. What is genetic engineering?
Ans. It is the
changes in the genetic material of organism made in laboratories for obtaining
desirable effects. Genetc engineering usually utilizes bacterial cells and
their pasmids. Genetic engineering produces cells containing foreign genes.
These cells are capable of producing new and different proteins.
Q.2. What are the steps o recombinant
DNA technology? Give names only.
Ans. This
technology has following steps
1. Preparation of
Recombination DNA (rDNA)
§ Vector
§ Restriction Enzyme
§ DNA Ligase Enzyme
2. Insertion of DNA
into Host Cell
3. Multiplication of Host rDNA
Q.3. What is vector? What is its
significance?
Ans. It is the DDNA
molecule into which the genne is inserted to construct an rDNA molecule. It
acts as a vehicle to transport rDNA into the host cell, which is usually a
bacterium. Two common vectors are used in this technique are plasmid or
bacteriophage.
Q.4. What are plasmids? What is their
use in biotechnology?
Ans. Plasmids are
small extra chromosomal circular molecule o DNA found in some bacteria. It can
replicate independent of the host chromosome. Plasmids are source of inserting
a foreign gene into them. Host cell take up this rDNA as vector and there after
bacteria and plasmid reproduce.
Q.5. How a DNA molecule is introduce
the foreign gene into the DNA?
Ans. These enzymes
are required to cut a source of DNA molecule into small pieces and to cut
plasmid to make a gap for foreign gene. These enzymes are naturally found in
bacteria. Restriction enzyme cuts DNA at a specific site called sticky ends.
The sticky ends of restriction fragments are used in laboratory to join foreign
DNA pieces.
Q.6. How cuted DNA molecule is
sealed?
Ans. DNA ligase is
a key enzyme that seals the restriction fragment with sticky ends of vector.
Q.7. What do you mean by insertion of
DNA into the host cell?
Ans. During this
technology bacteria are used as host. Bacterial cells take up rDNA when they
are treated with calcium chloride to make them more permeable. Some of the
bacterial cells will take the desired plasmid DNA from solution.
Q.8. How rDNA molecules are passed
into progeny?
Ans. When host cell
divides the copies if rDNA molecules are passed into progeny. After a large
number of cell divisions a colony of the host cells is produced. Each cell of
the colony contains one or more copies of the rDNA molecule.
Q.9. Give some application of
biotechnology.
Ans. Application of Genetically Engineered
Bacteria
1. In Agriculture – In agriculture, these bacteria promote the health of plant in
different ways such as to make them resistant against insects fungi and
bacteria. Some bacteria living in root of corn are transformed into insect
killing toxins.
2. Oil Eating
Bacteria – Some bacteria have ability to
degrade some chemicals e.g. oil eating bacteria, which were used to clean up
the ol spills at beeches.
3. Insulin
Production – Now a days insulin is produced by
genetically engineered bacteria. Human growth hormone now synthesized by
genetically engineered bacteria.
4. Nutra Sweet – Some genetically engineered bacteria are used to produce phenylalanine,
an organic compound to make nutra sweetener called nutra sweet.
5. In Minings – Some genetically engineered bacteria are used by miners to
extract copper, uranium and gold from low grade sources.
6. Diagnosis of
Disease – Biotechnology also contributes in
the diagnosis of genetic diseases.
7. Production of
Vaccines – Vaccines are produced from bacteria
treated with 8 rDNA technology.
8. Protection of
Crops – Cotton, corn, potato and soya bean
plants have been engineered to be resistant to either insect predators or
herbicides.
9. Enhancing Proof
Quality – Biotechnology is also helpful in
the enhancement in the food quality of crops.
Q.10. What are transgenic plants?
Ans. Those plants
which are genetically engineered are called transgenic plants. Some techniques
have been developed to produce transgenic plants. The rDNA can be introduced
into embryo or must be in cell wall removed cell called protoplast. The only
plasmid transgenic plant is Ti-plasmid, transferred by its host agrobacterium
to many but all plants.
Q.11. What are the aims and objects
of transgenic plants?
Ans. AIMS OF DEVELOPING TRANSGENIC PLANTS
i. To cultivate
more nutritious plants. Protein enhanced beans, soya beans, corn and wheat are
now developed.
ii. Plants require less fertilizer and are able to fix nitrogen more
efficiently.
iii. Plants grow under harsh and unfavorable conditions. A number of transgenic
plants have been developed which resist either insects, viruses. The first
transgenic fruit approved retarded spoilage. Plants are being engineered to
produce fructose instead of dextrose, human harmones clotting factors and
antibodies.
Q.12. What are transgenic animals?
Ans. Genetic
engineering of animals has begun. Animal cells do not take plasmids but it is
possible to micro insect’s foreign gene into the eggs of various animals before
they are fertilized. It had been done of the hope that the gene will establish
itself and transmitted to all the cells of the developing organism.
Q.13. What is restriction fragment
length polymolphism (RFLPS)? What is DNA finger printing? What are their uses?
Ans. DNA patterns
among individual are called restriction fragment length polymorphorism (RFLPs).
Since RFLPs of each human is unique, which are used as mark of identity, RFLPs
is termed as DNA finger printing. For this purpose DNA drum the samples are cut
into fragments are separated in the basis of their sizes. DNA fragments are
helpful to settled disputes over parentage. It is also used to identify
criminals from blood, semen, saliva etc. left at the site of crime.
Q.14. What is genomic library?
Ans. It consists of
copy of genetic information of species in a preferred environment. In order to
establish genomic library of particular specie its DNA is cut into fragments by
help of restriction enzymes and then fragments are inserted into plasmids and
bacteriophage and then into the bacteria. Such bacteria cultured for future
use.
Q.15. Into how many categories the
genetic diseases can be divided and what are their mode of treatment?
Ans. DETECTION AND TREATMENT OF GENETIC
DISEASES
Genetic diseases
fall into three categories;
i. Chromosomal – In this condition child born with structurally or numerically
abnormal chromosome such as down’s syndrome, Turner’s syndrome and
Klinefelter’s syndrome.
ii. Unifactorial
Defects – These defects are caused by
defective gene or pair of genes e.g. huntingtons disease and cystic fibrosis.
iii. Multifactorial
Defects – These defects are caused by
additive effects of several genes, along with environmental factors e.g.
asthma, diabetes mellitus.
a. Hungtinton’s
Disease – It is due to autosomal dominant
allele on chromosome number 4. Appearance of symptoms is usually delayed until
the age of 40-50 years. This disease is characterized by progressive mental
deterioration.
b. Cystic
Fibrosis – It occurs due to an autosomal
recessive allele. It is characterized by a tendency to chromic lung infection
an inability to absorb fats and other nutrients from food.
Q.15. What is gene therapy?
Ans. One of the
benefits of genetic engineering is to treat genetic diseases in individual. It
could be possible to replace defective gene with a normal gene. This could be
done with somatic cells or with germ cells.
Q.16. What is sever combined imuno
deficiency disease and how it can be treated? Give its sign and symptoms.
Ans. SEVERE COMBINED IMUNO DEFICIENCY
DISEASE (SCID)
This disease is
characterized by very poor immune system so the victim cannot resist infections
like pneumonia, influenza etc. In this condition the cells of the bone marrow
cannot produce an enzyme called adenosine deammase which is important for
normal immune response. This diseases treated by the help of gene therapy. In
this therapy the defective bone marrow cells of the patient are removed and
then insert the normal gene for the ADA enzyme into the bone marrow cells and
return the cells into bones of the parient. Now the cells of bone marrow
produce ADA enzyme and immune system becomes normal.
Q.17. What is aminocentesis and how
it works for the diagnose of diseases?
Ans. It is the
diagnostic procedure in which a small amount of amniotic fluid is withdrawn
from the amniotic sac. The amniotic fluid contains cells and chemicals from the
foetus that can be analyzed to detect fetal abnormalities such as Down’s
syndrome, heamophilia. Tay sachs disease etc.
Q.18. What are the disadvantages of
biotechnology?
Ans. WORRIES ABOUT BIOTECHNOLOGY
i. Creation of
Pathogens – The genetic manipulation of
microorganism could create hazardous new pathogens which might escape from lab.
ii. Side Effects of
Medical Products – There is a potential for harmful
side effects of the medical products.
iii. Introduction of
New Organisms – There is also a debate on this
burning topic that genetically engineered agricultural products because of
potential dangers of introducing new organisms into environment.
iv. New Proteins – There is another worry that food produced by recombinant
technology will contain new proteins that may cause severe allergies in some
people.
v. Resistance in
Plants – Genetically engineered crops could
become superweed. Plants resistant to herbicides or microbial disease and pest
insects could escape into wild and over grow and will become difficult to
control.
Genetic engineering is one of the hottest branches of biotechnology at present. And it's reported a company is only one step away from the success of developing chemicals that can spot gene damage site. Genetic engineering will also contribute to drug discovery then It won't be very far from the time when disease can be treated from the root.
ReplyDeleteYour interpretation of the genomic library is very good, I am a student of genomics, and this information will be used, very grateful!
ReplyDelete