Roll No:
Code No: 044/2
Candidate must write the Code on
the title page of the answer-book
PREBOARD EXAMINATION-2013

Please check that the question paper contains 06 pages.

Code No. written on the right hand side of the question paper should be
written on the title page of the answer book by the candidate.

Please check that this question paper contains 30 questions.

Please write down the serial number of the question before attempting it.

15 minutes time has been allotted to read this question paper.
BIOLOGY (THEORY)
CLASS-XII
Time Allowed: 3 hours
Maximum Marks: 70
General Instructions:
i.
All questions are compulsory.
ii.
This question paper consists of four sections A, B, C and D. Section A
contains 8 questions of one mark each, Section B is of 10 questions of
two marks each, Section C is of 9 questions of three marks each and
Section D is of 3 questions of five marks each.
iii.
There is no overall choice. However, an internal choice has been
provided in one question of 2 marks, one question of 3 marks and all
the questions of 5 marks weightage. A student has to attempt only
one of the alternatives in such questions.
iv.
Whenever necessary, the diagrams drawn should be neat and
properly labelled
SECTION –A
1.
Some IUDS increase Phagocytosis of sperms and suppress sperm motility.
Identify the IUD and give one example of it.
2.
In human beings the condition of karyotype is in2
disorders caused due to this.
3.
A far greater number of people suffer from protein and vitamin deficiency.
What is the phenomenon called? How can this be overcome?
4.
A disease can be detected before its symptoms appear. Name two diagnostic
techniques for it.
5.
What is the significance of adding proteases at the time of isolation of
genetic material?(DNA)
6.
Name the direct method of gene transfer in plants. How is it done?
7.
Name the unlabelled areas ‘a’ and ‘b’ of the pie chart representing the global
biodiversity of vertebrates showing their proportionate number of species of
major taxa.
8.
Which one of the two, stenothermals or eurythermals show wide range of
distribution on earth and why?
9.
A moss plant produces a large number of antherozoids but relatively only a
few egg cells. Why?
2
10.
A non-haemophilic couple was informed by their doctor that there is
possibility of a haemophilic child be born to them. Draw a checker board and
find out the percentage of possibility of such child in the progeny.
2
11.
Study the given portion of double stranded polynucleotide chain carefully.
Identify a, b, c and the 5’-end of the chain.
2
1. Name the genetic
SECTION –B
12.
How do you consider tendrils of Cucurbita and thorns of Bougainvillea as
homologous structure? Name the type of evolution of which the
homologous organs are result of.
2
13.
How can DNA segments, separated by gel electrophoresis, be visualised and
isolated?
2
14.
Identify the curves ‘a’ and ‘b’ shown in the graph given below. List the
conditions responsible for growth patterns ‘a’ and ‘b’.
2
15.
Identify a,b,c and d in the table given below
S. No.
Name of the
Name of the causal
human disease
bacteria/virus
(i)
(ii)
(iii)
Typhoid
Common cold
Pneumonia
Specific organ
or it’s part
affected
a
c
d
Salmonella typhi
b
Streptococcus
pneumoniae
OR
Write the scientific names of the causal organisms of elephantiasis and ring
worm in humans. Mention the body parts affected by them in a tabular
form.
2
16.
17.
18.
How did Eli Lilly Company go about preparing the human insulin? How is the
insulin thus produced different from that produced by the functional human
insulin gene.
(a) Energy pyramid cannot be inverted. Justify.
(b) List any two limitations of ecological pyramid.
2
By the end of 2002 the public transport of Delhi switched over to a new fuel.
Name the fuel. Why is this fuel considered better? Explain.
2
2
SECTION-C
19.
Fertilisation is essential for production of seed, but in some angiosperms
seeds develop without fertilisation.
(a) Give an example of an angiosperm that produces seed without
fertilisation. Name the process
(b) Explain the two other ways by which seeds develop without
fertilisation.
Mohan went to a super market with his father to buy rice. They saw that two
types of products are available-one is organically grown and second is
conventionally grown. The organically grown crops are costlier so Mohan’s
father did not want to purchase it but Mohan emphasized on purchase of
organically grown rice.
Answer the following questions based on the above information:
(a) Which rice should be purchased? Why?
(b) What values are exhibited by Mohan?
3
21.
Briefly explain the mechanism of sex determination in honey bee.
3
22.
How is translation of m-RNA terminated? Explain.
3
23.
Draw a diagram of the matured human sperm and label
(a) Acrosome
(b) Mitochondria
(c) Neck
(d) Chromosomal material.
OR
Draw a diagrammatic longitudinal sectional view of matured anatropous
ovule and label the following parts
(a) that develops into seed coat.
(b) that develops into an embryo.
(c) That develops into an endosperm in an albuminous seed.
(d) Through which the pollen tube gains entry into the embryo sac.
3
24.
Name the technique used to increase the herd size of cattle in short . Explain
the technology.
3
20.
3
25.
a. What is Eco RI? What does R represent in this?
b. Give the palindromic nucleotide sequence recognised by it.
c. Explain its action.
3
26.
a. Name the book published by IUCN which contain the information about all
organisms of the world facing extinction.
b. Why are certain regions declared as biodiversity hot spot ?
c. Name any two hot spot regions of India.
Mention the conservation strategy which is linked with hot spot.
3
27.
a. Expand BOD.
b. At a particular segment of river near a sugar factory, the BOD is much
higher than the normal level. What is it indicative of? What will happen to
the living organism in this part of the river?
c. Under what conditions will the BOD be lowered in the river? How will it
affect the aquatic life?
3
SECTION-D
28.
a. During his studies on genes in Drosophila that were sex linked ,
T.H.Morgan found population phenotypic ratio deviated from expected
9:3:3:1.Explain the conclusion he arrived at.
b. A woman with blood group O married a man with AB group. Show the
possible blood groups of the progeny .List the alleles involved in this
inheritance.
OR
Who demonstrated the semi conservative replication of DNA? Explain the
procedure in detail.
5
29.
(a) Name the genus to which Baculoviruses belong. Describes their role in
the integrated pest management programme.
(b) How is Rhizobium categorised as a ‘symbiotic bacterium’? How does it
act as a biofertilizer?
(c) How do cyanobacteria act as biofertilizers?
OR
(a) Why is using tobacco in any form injurious to the health? Explain.
(b) Name a drug used (i) as an effective sedative and pain killer (ii) for
helping patients to cope with mental illness like depression, but often
misused.
(c) How does the moderate and high dosage of cocaine affect the human
body?
(d) From which plant are Cannabinoids obtained? Name any two
Cannabinoids. Which part of the body is affected by consuming these
substances?
5
30.
(a) Given below is the T.S. of human ovary. Identify the following in the
diagram:
f
(i) corpus luteum
(ii) secondary oocyte
(iii) Antrum
(iv) Primary Follicle
(v) Primary oocyte
(vi)Graafian follicle
(b) Meiotic division during oogenesis is different from that in
spermatogenesis. Explain how and why?
OR
(a) Explain the development of a matured embryo sac from a megaspore
mother cell in angiosperm .
(b) How are seeds advantageous to flowering plants?
5