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KENDRIYA VIDYALAYA SANGATHAN , VARANASI REGION
FIRST PRE-BOARD EXAMINATION 2015-16
SUBJECT :
BIOLOGY (THEORY)
CLASS
:
TIME :
3 hrs
Max. Marks :
SECTION – A
Q.1.
Juvenile phase
Q.2.
Transcription of m-RNA / hnRNA
Q.3
44+X0
Q.4
Bharatpur, Rajasthan
Q.5
Cannabinoid. Canabis sativa
SECTION – B
Q.6
Q.7
Q.8
Q.9
Q.10
Q.11
XII
70
a) 3/8
b) 1/8
No. It is so because marine fish is adapted to live in saline sea water. In fresh water, it will
not be able to cope with the outside hypotonic environment because of osmoregulation
problem.
According to 10 percent law , only about 10% biological useful energy is available to next
trophic level from the previous level in a food chain. Hence, energy goes on decreasing at
successive trophic level. Hence after three to four trophic levels the sufficient energy for
sustenance is not available.
OR,
Organs of two different organisms which are structurally different but perform the similar
functions are called analogous organs. Sweet potato tuber (root modification) and potato
tuber (stem modification) is an example for analogy in plants.
Each testicular lobule in human male contains one to three highly coiled seminiferous
tubules. Each seminiferous tubule is lined on its inside by two types of cells called male
germ cells (spermatogonia) and Sertoli cells. The regions outside the seminiferous tubules
called interstitial spaces, contain small blood vessels and interstitial cells or Leydig cells.
SECTION – C
c
Parents :
AA+ X Y X AA+XCX
Gametes :
A+XC , A+Y
A+XC , A+X
C
C
C
F1
:
AA+ X X
AA+XX
AA+XCY
AA+XY
Colour blind son
Normal son
1M
1M
1M
1M
½ +1/2
1+1
=2
M
2M
1+1
=2 M
2M
2M
1
1
1
=3
Q.12
3
OR
The embryos with more than 8 blastomeres could be transferred into the uterus to
complete its further development. This process is known as (IUT – intra uterine transfer).
Q.13
Q.14
Q.15
Intra cytoplasmic sperm injection (ICSI) : It is a specialised procedure to form an embryo
in the laboratory in which a sperm is directly injected into the ovum.
Artificial insemination (AI) technique: In this technique, the semen collected either from
the husband or a healthy donor is artificially introduced either into the vagina or into the
uterus (IUI – intra-uterine insemination) of the female.
I) In some flowering plants, the male and female flowers are present on separate
individuals. Such plants are called dioecious.
II) Chara
A- Oogonium B)Antheridium
Male part is Antheridium (B)
A) 650-800 cc
B) The Neanderthal man
C) About 15 mya
Q.17
1
1
1
1
½
1
½
1
1
1
Differences :
Sex determination in Birds
Sex determination in Human
1
ZZ-ZW Type
XX-XY type
2
Female heterogametic
Male heterogametic
The two types of chromosomes in human beings are : Autosomes and Allosomes (Sexchromosomes)
Q.16
or
In many cultures, tracts of forest were set aside, and all the trees and wildlife within were
venerated and given total protection. These are called sacred groves.
India has also a history of religious and cultural traditions that emphasised protection of
nature. Sacred groves are found in Khasi and Jaintia Hills in Meghalaya, Aravalli Hills of
Rajasthan, Western Ghat regions of Karnataka and Maharashtra and the Sarguja, Chanda
and Bastar areas of Madhya Pradesh. In Meghalaya, the sacred groves are the last refuges
for a large number of rare and threatened plants.
Advantages of micro propagation :
i)
By application of this method it is possible to achieve propagation of a large
number of plants in very short durations.
ii)
Each of these plants are genetically identical to the original plant from which
they were grown, i.e., they are somaclones.
iii)
Another important application of the method is the recovery of healthy plants
from diseased plants.
1
1
1
1
1
1
1x3=
3
Q.18
MALT – Mucosal Associated Lymphoid Tissues
1
2
Q.19
Q.20
Q.21
Q.22
Steps taken in Delhi for reducing vehicular pollution include :
All the buses of Delhi were converted to run on CNG by the end of 2002.
Phasing out of old vehicles, use of unleaded petrol, use of low-sulphur petrol and diesel,
use of catalytic converters in vehicles, application of stringent pollution level norms for
vehicles, etc.
Thanks to the efforts made, the air quality of Delhi has
significantly improved. According to an estimate, a substantial fall in CO2 and SO2 level
has been found in Delhi between 1997 and 2005.
A : Propionibacterium sharmanii
B : yeast (fungi)
C : Biocontrol Agent
GPP (Gross primary Productivity) of an ecosystem is the rate of production of organic
matter during photosynthesis. A considerable amount of GPP is utilised by plants in
respiration.
NPP (Net primary productivity) : It is the available biomass for the consumption to
heterotrophs (herbivores and decomposers).
Gross primary productivity minus respiration losses (R), is (NPP).
GPP – R = NPP
Primary productivity depends on the plant species inhabiting a particular area. It also
depends on a variety of environmental factors, availability of nutrients and photosynthetic
capacity of plants.
- Restriction endonuclease (EcoRI) inspects the length of the DNA sequence of both vector
and foreign DNA ,
- binds to the specific recognition sequence / palindromic sequence ,
- cuts the strand of DNA between G and A ,
- only when the sequence GAATTC is present in the DNA ,
- leaving single stranded overhanging stretches called sticky ends ,
- Ligases joins host and foreign DNA strands at sticky ends to form recombinant DNA
(diagram can also be accepted in lieu of flow chart)
2
1
1
1
1
2
1
½×
6=3
OR
Gel electrophoresis
• Negatively charged DNA fragments are forced to move towards the anode under electric
field on agarose gel ,
• DNA fragments get separated according to their size / Small fragments cover large
distance& large fragments cover small distances ,
1
½×
4=2
Q.23
Q.24
• These fragments are visualised after staining with ethidium bromide followed by
exposureunder UV rays
• The separated bands of DNA are cut out from the gel & extracted (elution)
SECTION – D
a) Yes, so that it does not become a habit by repeated use / consumption of drugs may
cause harmful effects / any other reason
(b) • Drug : Cocaine - Source is plant Erythroxylum coca
Danger - effects central nervous system / interferes with transport of neurotransmitter
(dopamine)
• Drug : Opioids / heroin / smack - source is latex of Papaver somniferum / poppy plant
Danger - slows down body function
• Drug : Cannabinoids source is Cannabis (sativa)
Danger - effects cardiovascular system
( Any two drugs and their danger ) = 1 + 1
(c) By organising : Poster competitions / Street play / talk by experts / interviews / any other appropriate
awareness campaign (any two)
SECTION – E
The major tasks under Reproductive and Child Health Care (RCH) programmes are:
i)
Creating awareness among people about various reproduction related
aspects and
ii)Providing facilities and support for building up a reproductively healthy society .
Natural methods work on the principle of avoiding chances of ovum and sperms meeting.
These are :
i) Periodic abstinence: In this method the couples avoid or abstain from coitus from day 10
to 17 of the menstrual cycle when ovulation could be expected. As chances of fertilisation
are very high during this period, it is called the fertile period. Therefore, by abstaining
from coitus during this period, conception could be prevented.
ii) Withdrawal or coitus interruptus: In this method the male partner withdraws his penis
from the vagina just before ejaculation so as to avoid insemination.
iii) Lactational amenorrhea (absence of menstruation) method: It is based on the fact that
ovulation and therefore the cycle do not occur during the period of intense lactation
following parturition. Therefore, as long as the mother breast-feeds the child fully,
chances of conception are almost nil.
1
½
½
½
½
1
2
1
1
1
OR
The inheritance pattern of flower colour in the dog flower (snapdragon or Antirrhinum sp.)
1
is different from the pea plant in the sense that while Snapdragon shows incomplete
dominance the pea plant shows complete dominance.
Snapdragon: In a cross between true-breeding red-flowered (RR) and true breeding whiteflowered plants (rr), the F1 (Rr) was pink . When the F1 was self-pollinated the F2 resulted 1
in the following ratio 1 (RR) Red: 2 (Rr) Pink : 1 (rr) White. Here the genotype ratios were
exactly as we would expect in any Mendelian monohybrid cross, but the phenotype ratios
had changed from the 3:1 dominant : recessive ratio.
What happened was that R was not completely dominant over r and this made it possible
to distinguish Rr as pink from RR (red) and rr (white) .
1
Pea plant:
Inheritance pattern of Garden Pea plant follows Law of dominance . The F1 hybrids shows
100% dominant trait whereas on selfing in F2 the phenotypic ratio is 3:1 and genotypic
ratio is 1:2:1.
1
1
Q.25
2
The unequivocal proof that DNA is the genetic material came from the experiments of
Alfred Hershey and Martha Chase (1952). They worked with viruses that infect bacteria
called bacteriophages.
They grew some viruses on a medium that contained radioactive phosphorus and some
others on medium that contained radioactive sulfur. Viruses grown in the presence of
radioactive phosphorus contained radioactive DNA but not radioactive protein because
DNA contains phosphorus but protein does not. Similarly, viruses grown on radioactive
sulfur contained radioactive protein but not radioactive DNA because DNA does not
contain sulfur.
Radioactive phages were allowed to attach to E. coli bacteria. Then, as the infection
proceeded, the viral coats were removed from the bacteria by agitating them in a blender.
The virus particles were separated from the bacteria by spinning them in a centrifuge.
3
Bacteria which was infected with viruses that had radioactive DNA were radioactive,
indicating that DNA was the material that passed from the virus to the bacteria. Bacteria
that were infected with viruses that had radioactive proteins were not radioactive. This
indicates that proteins did not enter the bacteria from the viruses. DNA is therefore the
genetic material that is passed from virus to bacteria.
OR,
2
The elucidation of the lac operon was a result of a close association between a geneticist,
Francois Jacob and a biochemist, Jacque Monod.
In lac operon (here lac referes to lactose), a polycistronic structural gene is regulated by a
common promoter and regulatory genes. Such arrangement is very common in bacteria
and is referred to as operon.
The lac operon consists of one regulatory gene (the i gene – here the term i does not refer
to inducer, rather it is derived from the word inhibitor) and three structural genes (z, y,
and a). The i gene codes for the repressor of the lac operon. The z gene codes for betagalactosidase (B-gal), which is primarily responsible for the hydrolysis of the disaccharide,
lactose into its monomeric units, galactose and glucose. The y gene codes for permease,
which increases permeability of the cell to B-galactosides. The ‘a’ gene encodes a
transacetylase. Hence, all the three gene products in lac operon are required for
metabolism of lactose.
The repressor of the operon is synthesised (all-the-time – constitutively) from the i gene.
The repressor protein binds to the operator region of the operon and prevents RNA
polymerase from transcribing the operon.
In the presence of an inducer, such as lactose or allolactose, the repressor is inactivated
by interaction with the inducer. This allows RNA polymerase access to the promoter and
transcription proceeds.
Q.26
Polymerase Chain Reaction
• Denaturation / Separation of ds DNA (by high temperature)
• Annealing - Two sets of primers are added which anneal to 3’ end of each separated
strand as they act as initiator of replication
• Extension - DNA Polymerase / Taq polymerase , extends primer by adding nucleotides
using DNA as templates
3
3
2
OR,
-
Cry proteins are the crystalline toxic insecticidal protein.
It is produced by a bacterium named Bacillus thuringiensis.
Some strains of Bacillus thuringiensis produce proteins that kill certain insects such
as lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and
dipterans (flies, mosquitoes).
B. thuringiensis forms protein crystals during a particular phase of their growth.
These crystals contain a toxic insecticidal protein. Specific Bt toxin genes were
isolated from Bacillus thuringiensis and incorporated into the several crop plants
such as cotton. The choice of genes depends upon the crop and the targeted pest,
as most Bt toxins are insect-group specific. The toxin is coded by a gene named cry.
There are a number of them, for example, the proteins encoded by the genes
cryIAc and cryIIAb control the cotton bollworms that of cryIAb control corn borer.
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