AHSEC| CLASS 12| BIOLOGY| SOLVED PAPER - 2019| H.S. 2ND YEAR
2019
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 Page No. 1 - 6 PART-II (ZOOLOGY) MARKS - 35 Page No. 7 – 11 |
Use separate Answer scripts for
Part-I (Botany) and Part-II (Zoology)
Part-I (Botany)
1. Name the edible part of an apple. 1
Ans:- The thalamus.
2. Why grafting is not possible in monocot plants? 1
Ans:- Grafting is not possible in monocot plants
because they lack cambium tissue.
3. Name the micro-organism that converts milk to
curd. 1
Ans:- Lactobacillus
Bacteria.
4. What is the function of DNA ligase? 1
Ans:- It catalyses the formation of phosphodiester
bonds between two DNA fragments.
5. What is missing link? Describe briefly with an example. 1+1=2
Ans:- The connecting links which have become extinct
are called missing links. For example, Archeopteryx is the link between
reptiles and birds.
Animals that
share characteristics of different animals are called connecting links. For
example the duck billed platypus.
Connecting links
may survive or become extinct while missing links become extinct.
0r
Define
Recapitulation theory with examples.
2
Ans:- The
recapitulation principle, also known as the biogenetic law or embryological
similarity, is the idea that an animal's embryonic development resembles the
evolutionary history of its ancestors.
Here are
some examples of recapitalization theory:-
(i) Tadpole:
The tadpole stage of development of frog is similar to that of fish, which
shows that amphibians have evolved from fish.
(ii) Human
embryo: The pharyngeal grooves in the human embryo are similar to the gill
slits of fish.
6. What is transgenic plant? Mention two advantages and
one example of transgenic plant.
1+1=2
Ans:- Plants in which a foreign gene is introduced to
produce a specific product or to provide new characteristics to maintain it in
the environment are called transgenic plants.
Some
advantages of transgenic plants are as follows:-
(i) Disease,
insect and herbicide resistance: Transgenic plants are more resistant to
diseases and insects, and may also be resistant to herbicides.
(ii) Increase in
crop yields: Transgenic plants have increased crop yields, which can improve
food security and reduce the use of pesticides.
Example of
transgenic plant:-
(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.
0r
Write on the
importance of biopiracy. 2
Ans:- Biopiracy
is the unauthorized appropriation of knowledge and genetic resources of farming
and indigenous communities by individuals or institutions seeking exclusive
monopoly control through patents or intellectual property. This is a serious
environmental issue that has arisen in recent years, and it is having a
devastating impact on many of the world's tropical environments.
There are many
reasons why biopiracy is important. First of all, it is a form of theft.
Indigenous communities have been using genetic resources and traditional
knowledge for centuries, and have the right to benefit from their use. When
companies patent these resources without permission, they are depriving
indigenous communities of their fair share of the profits.
7. Differentiate allelopathy and antibiosis. 1+1=2
Ans:- Allelopathy and antibiosis are both biological
processes that involve the production of chemicals that affect other organisms.
Here are some
differences between allelopathy and antibiosis:-
(i) Chemical
orientation: Allelopathy is a chemical-based process, whereas antibiosis is
antibody-based.
(ii) Effects
on other organisms: Allelopathy can have positive or negative effects on
other organisms, whereas antibiosis has only negative effects.
(iii) Growth
inhibition: Allelopathy can either inhibit or promote the growth of other
organisms, whereas antibiosis always inhibits the growth of other organisms.
(iv)
Association: Allelopathy is an association between two or more organisms
that is harmful to at least one of them. Antibiosis is an antagonistic
relationship between organisms that causes harm to one of them.
0r
What is age
pyramid? Draw the expanding age pyramid and label its parts. 1+1=2
Ans:- Age
pyramids are graphical representations of the age and sex of a population. For
this reason, the population pyramid is also called the age-sex pyramid.
The age
pyramid shows the age distribution of men and women in a combined diagram. In
extended age pyramids, there are more men and women in reproductive age. High
birth rate and low death rate increases the number of young people which leads
to population growth.
8. Write short note on the following: (any one) 2
(i) Gene gun
Ans:-
Gene gun, also known as biolistic particle delivery system, is a device used to
deliver DNA, RNA or proteins to cells. This technology is also known as bio
ballistics, short for "biological ballistics".
(ii) Tools of
genetic engineering
Ans:- Here
are some of the tools used in genetic engineering:-
(i)
Restriction enzymes: These enzymes are essential tools in genetic
engineering.
(ii)
Cloning: This tool allows scientists to make exact genetic copies of living
things.
(iii)
Selectable marker genes: These genes allow scientists to identify or
isolate cells expressing cloned DNA and to monitor and select the transformed
progeny.
(iv) Gene
gun: This technology is commonly used to insert genetic material into cells
by particles coated with short DNA sequences.
(v)
Plasmids: These are used in genetic engineering to amplify certain genes or
to produce multiple copies of them.
(iii) Gene
cloning
Ans:- Gene
cloning is a set of experimental methods used in molecular biology to assemble
recombinant DNA molecules and direct their replication within host organisms.
9. What are the conditions of biopatent? 2
Ans:- Conditions of biopatent: To be protected by a
patent, an invention must be novel, inventive (show inventive activity), have
industrial applicability and be lawful.
0r
Write about
the function and principle of ELISA technique.
2
Ans:- The
ELISA (enzyme-linked immunosorbent assay) technique is a widely used laboratory
technique that detects and measures the presence of antigens and antibodies in
a sample. It is based on the principle of antigen-antibody binding, which is a
fundamental immunological reaction.
ELISA stands
for Enzyme-Linked Immunosorbent Assay. It is a commonly used technique in biochemistry,
plant pathology, medicine and biotechnology. The function of ELISA is to detect
and measure the presence of a substance in a liquid sample. This can be done
using antibodies that are specific to the substance being tested.
The ELISA
technique works by first attaching the antigen from the sample to the surface.
Then, a matching antibody is applied to the surface so that it can bind the
antigen. This antibody is bound to an enzyme and any unbound antibody is then
removed. In the final step, a substance containing the enzyme substrate is
added. If there was binding, the subsequent reaction produces a detectable
signal, usually a colour change.
Principle of
ELISA: ELISA works on the principle that specific antibodies bind the target
antigen and detect the presence and amount of antigen binding. To increase the
sensitivity and accuracy of the assay, the plate should be coated with high
affinity antibodies. ELISA can provide a useful measurement of antigen-antibody
concentration.
10. Write scientific name and utility of the following
plants: (any two) 1+1=2
(a) Teak
Ans:-
Teak is a tropical hardwood tree whose scientific name is Tectona grandis. It
is also known as Sagwan tree. Teak is grown in tropical regions and is widely
harvested for its wood. Teak wood is known for its durability, strength and
natural resistance to decay. It is used for a variety of purposes, including
outdoor furniture, boat building, door and window frames, flooring, fine
furniture, and veneer. Teak is also used as a natural dye and as a biosorbent
to remove heavy metals.
(b) Indian
ginseng
Ans:- Withania
somnifera, known as Ashwagandha, is widely considered to be Indian ginseng. In
Ayurveda, it is classified as Rasayana (rejuvenating) and is expected to
promote physical and mental health, rejuvenate the body in debilitating
conditions and increase longevity.
(c) Chinchona
Ans:-
Cinchona officinalis is a medicinal plant, one of several Cinchona species used
to produce quinine, an anti-fever agent. It is particularly useful in the
prevention and treatment of malaria. Other alkaloids extracted from this tree
include cinchonine, cinchonidine, and quinidine.
(d) Sissoo
Ans:- The
scientific name of Sissu plant is Delbergia Sissu. It is a medium to
large-sized deciduous tree native to the Indian subcontinent and southern Iran.
This tree is also known as Sheesham, Tahli, Sisu and North Indian Rosewood.
The Sissu
plant has a wide range of uses. The wood of the tree is extremely durable and
is used to make high-quality furniture, flooring and other items. The leaves of
the tree are used as animal fodder, and the flowers are used to make honey.
This tree is also planted as an ornamental plant and is used for soil
conservation and shade.
11. Write briefly the chemical origin of life on the earth. 3
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