AHSEC| CLASS 12| BIOLOGY| SOLVED PAPER - 2017| H.S. 2ND YEAR
2017
BIOLOGY
(Theory)
Full Marks: 70
Pass Marks: 21
Time: Three hours
The figures in the margin indicate full marks for the questions
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PART-I (BOTANY) MARKS – 35
PART-II (ZOOLOGY) MARKS - 35
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Use separate Answer scripts for
Part-I (Botany) and Part-II (Zoology)
Part-I (Botany)
1. Who is regarded as the father of green revolution? 1
Ans:- Dr. M. S. Swaminathan.
2. The pollination done by snails is called ………... 1
Ans:- Malacophily.
3. What is GMO? 1
Ans:- Genetically modified organisms (GMOs)
are those in which the DNA of a desired organism is inserted in the laboratory.
These are also called transgenic organisms.
4. Name the bacterium which was controlled with
penicillin by Alexander Flemming. 1
Ans:- Alexander Fleming discovered penicillin
in 1928 while studying the properties of staphylococci. They found that their
"mold juice" could kill many types of harmful bacteria, including
streptococci, meningococci, and diphtheria bacillus.
5. What are the disadvantages of asexual reproduction? 2
Ans:-
Disadvantages of asexual reproduction:-
(i) The offspring produced by
asexual reproduction is a clone, and any harmful mutation will also be passed
on to the offspring.
(ii) The life span of the organisms
produced is short.
(iii) It is difficult to control the
increasing population.
(iv) There is only limited diversity
in life forms.
(v) Children will not be able to
adapt to their environment.
(vi) The offspring have to compete
for food and space among the species.
Or
Define
parthenogenesis. Give an example of natural parthenocarpic fruit. 1+1=2
Ans:- Parthenogenesis occurs when a fruit forms
without fertilization. This fruit is seedless and looks like a normal fruit.
Parthenocarpy is the development of
fruits without fertilization. Parthenocarpy can occur naturally or be induced
artificially using plant hormones.
Examples of naturally occurring
parthenocarpic fruits include:-
Orange, grapes, cucumber, pineapple,
banana, grapes, persimmon, breadfruit.
6. What is biofortification? What are the objectives of
it? 1+1=2
Ans:- Biofortification is a breeding
process aimed at increasing the nutritional value of food crops. The process
involves using traditional plant breeding techniques, modern biotechnology
techniques and agronomic practices to increase the mineral density and
bioavailability of crops such as rice, wheat, beans and other grains and
legumes.
The objectives of biofortification
include:-
(i) Improvement in protein content
and quality
(ii) Improvement in quantity and
quality of oil
(iii) Improvement in vitamin content
(iv) Improvement in micronutrient
and mineral content
(v) Overcoming malnutrition
Or
What is
selection? Name two methods of selection. 1+1=2
Ans:- When individual plants or a group of plants
having desired traits are selected from the population by removing undesirable
traits, it is called selection.
There are two methods of selection:-
mass selection and pure-line selection.
7. What is transgenic plant? Give two examples.
1+0.5+0.5=2
Ans:- Plants in which a foreign gene is
introduced to produce a specific product or to give it new characteristics to
survive in the environment are called transgenic plants.
Examples of transgenic plants are:-
(i) One of the transgenic plants is
Golden Rice. A beta-carotene gene is inserted into the rice plant, which
produces beta-carotene.
(ii) It is generally found in
carrots, which when added to rice plants, starts producing beta-carotene.
Or
What is
recombinant DNA? How does enzyme endonuclease help its formation? 1+1=2
Ans:- The technology used to produce artificial DNA
through combining different genetic materials (DNA) from different sources is
called Recombinant DNA Technology. Recombinant DNA technology is popularly
known as genetic engineering.
Recombinant DNA is made using a restriction
enzyme that cuts the double strand at a particular point. The same enzyme is
used to cut another piece of DNA. When the fragments are mixed together, the
complementary ends of each strand will join with the other, creating a
recombinant DNA molecule.
8. Give the full form of ELISA. Name two diseases for the
detection of which ELISA technique is used. 1+0.5+0.5=2
Ans:- ELISA stands for Enzyme Linked
Immuno-Sorbent Assay.
Diseases identified by Elisa:-
ELISA is a test to diagnose HIV/AIDS
or to check the levels of hormones like thyroxine in the body.
Or
What is
EcoR1? 1+1=2
Ans:- EcoRI (pronounced "Echo R one") is a
restriction endonuclease enzyme found in E. coli bacteria. It is a restriction
enzyme that cuts the DNA double helices into fragments at specific locations.
EcoRI is a major player in the world
of molecular biology. It has a specific role in DNA manipulation. These enzymes
are commonly used in rDNA technology and genetic engineering techniques.
EcoRI produces sticky ends with a
5′-overhang.
9. Write short note on: (any one) 2
(a) Biopiracy
Ans:- Biopiracy is the practice of commercially
exploiting naturally occurring biochemicals or genetic materials. Generally,
indigenous peoples have traditional cognition that primarily involves the
biological characteristics of the natural environment and genetic diversity
passed from one generation to the next.
Some traditional knowledge relevant
to global survival has the elements listed below:-
(i) Farming or agriculture.
(ii) Medicinal plants.
(iii) Varieties of food crops.
Essential components for the
survival of rural and indigenous peoples include the conservation of habitats,
species and biodiversity.
(b) Gene
Cloning
Ans:- Gene cloning is a set of molecular biology
techniques used to create recombinant DNA molecules and direct their
replication within host organisms.
The general steps of gene cloning
are:-
(i) Prepare and isolate the source
DNA to be cloned
(ii) Prepare cloning vector
(iii) Combine vector and DNA
fragments to form recombinant DNA molecules
(iv) Introduce recombinant DNA into
the host recipient
PCR cloning is a type of cloning
that involves ligating DNA fragments directly into a vector. It is a rapid
method for gene cloning and is often used for projects that require high throughput.
10. How insulin is produced through genetic engineering?
2
Ans:- Insulin is produced by cutting and
pasting the human insulin gene into a plasmid through genetic engineering. The
plasmid is then inserted into a bacterial or yeast cell, which divides rapidly
and begins producing insulin.
Here are some of the steps involved
in the production of insulin through genetic engineering:-
(i) Separate genes for A and B
series
(ii) Use restriction enzymes to
release genes to the chains and vector DNA at specific points
(iii) Insert the gene into the
vector DNA plasmid and ligate using ligase enzyme
(iv) Recombinant DNA replicates
inside E. coli plasmid
(v) Remove A and B chains from E.
coli plasmid
(vi) Join chains by disulfide bonds
to produce human insulin
The final steps in the process involve
collecting the mixture, extracting and purifying the insulin, and formulating
it into the desired dosage form.
Or
Explain Gene
therapy by citing the example of Adenosine deaminase (ADA) deficiency. 2
Ans:- Gene therapy is the process of introducing DNA
into an organism. Man to cure some disease. It is used to replace a missing
gene product or correct mutant alleles. ADA is an autosomal-recessive
hereditary disorder caused by defective adenosine deaminase (ADA) enzymes.
Please suffer from severe combined immunodeficiency (SCID) conditions caused by
the deficiency of this enzyme. Human gene therapy trials can be used for
ex-vivo introduction of a functional ADA gene into the bone marrow cells of a
patient suffering from SCID. For this procedure, an engineered retrovirus
containing a functional ADA gene is used to transfer the ADA gene into stem
cells isolated from a patient with SCID. The treated cells or modified cells
with the good ADA gene are reintroduced into the patient's marrow.
11. Describe the process of development of male gametophyte in Angiosperms with suitable diagrams. 3
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