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  #1  
Old December 27th, 2013, 05:12 PM
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Will you please give me question paper for the class 12th examination organized by the CBSE board of education??

Well, as you require the previous year question paper of the Biology subject of class 12th of CBSE for the preparation of this exam so here I am providing you the same

1. How many chromosomes do drones of honey bees possess? Name the type of cell division
involved in the production of sperms by them. [1]
2. What is a cistron? [1]
3. Retroviruses have no DNA. However, the DNA of the infected host cell does possess viral
DNA. How is it possible? [1]
4. Why do children cured by enzyme-replacement therapy adenosine deaminase deficiency
need periodic treatment? [1]
5. List two advantages of the use of unleaded petrol in automobiles as fuel. [1]

SECTION B
6. Why do moss plants produce very large number of male gametes? Provide one reason.
What are these gametes called? [2]
7. [2]
(a) Select the homologous structures from the combinations given below:
(i) Forelimbs of whales and bats
(ii) Tuber of potato and sweet potato
(iii) Eyes of octopus and mammals
(iv) Thorns of Bougainvillea and tendrils of Cucurbita
(b) State the kind of evolution they represent.
8. [2]
(a) Why are the plants raised through micropropagation are termed as somaclones?
(b) Mention two advantages of this technique.
9. Explain the different steps involved during primary treatment phase of sewage. [2]
10.What is mutualism? Mention any two examples where the organisms involved are
commercially exploited in agriculture. [2]
OR
List any four techniques where the principle of ex-situ conservation of biodiversity has
been employed. [2]

SECTION C
11.State what is apomixis. Comment on its significance. How can it be commercially used? [3]
12.During a monohybrid cross involving a tall pea plant with a dwarf pea plant, the offspring
populations were tall and dwarf in equal ratio. Work out a cross to show how it is possible.
[3]
13.Explain the significance of satellite DNA in DNA fingerprinting technique. [3]
14.What does the following equation represent? Explain. [3]
2 2 p 2pq q 1


15.A heavily bleeding and bruised road accident victim was brought to a nursing home. The
doctor immediately gave him an injection to protect him against a deadly disease. [3]
(a) Write what did the doctor inject into the patient’s body.
(b) How do you think this injection would protect the patient against the disease?
(c) Name the disease against which this injection was given and the kind of immunity it
provides.
16.Enumerate any six essentials of good, effective Dairy Farm Management Practices. [3]
17.State the medicinal value and the bioactive molecules produced by Streptococcus, Monascus
and Trichoderma. [3]
OR
What are methanogens? How do they help to generate biogas? [3]
18.Rearrange the following in the correct sequence to accomplish an important biological
reaction: [3]
(a) In vitro synthesis of copies of DNA of interest
(b) Chemically synthesized oligonucleotides
(c) Enzyme DNA-polymerase
(d) Complementary region of DNA
(e) Genomic DNA template
(f) Nucleotides provided
(g) Primers
(h) Thermostable DNA-polymerase (from Thermus aquaticus)
(i) Denaturation of ds-DNA
19.Describe any three potential applications of genetically modified plants. [3]
20.How did an American Company, Eli Lilly use the knowledge of r-DNA technology to
produce human insulin? [3]
21.How do snails, seeds, bears, zooplanktons, fungi and bacteria adapt to conditions
unfavourable for their survival? [3]
22.With the help of a flow hart, show the phenomenon of biomagnifications of DDT in an
aquatic food chain. [3]

SECTION D
23.Your school has been selected by the Department of Education to organize and host an
interschool seminar on “Reproductive Health – Problems and Practices”. However, many
parents are reluctant to permit their wards to attend it. Their argument is that the topic is
“too embarrassing.”
Put forth four arguments with appropriate reasons and explanation to justify the topic to
be very essential and timely. [4]
SECTION E

24. [5]
(a) Plan an experiment and prepare a flow chart of the steps that you would follow to
ensure that the seeds are formed only from the desired sets of pollen grains. Name the
type of experiment that you carried out.
(b) Write the importance of such experiments.
OR
Describe the role of pituitary and ovarian hormones during the menstrual cycle in a human
female. [5]

25. [5]
(a) Why are thalassemia and haemophilia categorized as Mendelian disorders? Write the
symptoms of these diseases. Explain their pattern of inheritance in humans.
(b) Write the genotypes of the normal parents producing a haemophilic son.
OR
How do m-RNA, t-RNA and ribosomes help in the process of translation? [5]

26. [5]
(a) List the different attributes that a population has and not an individual organism.
(b) What is population density? Explain any three different ways the population density
can be measured, with the help of an example each.
OR
“It is often said that the pyramid of energy is always upright. On the other hand, the
pyramid of biomass can be both upright and inverted.”
Explain with the help if examples and sketches. [5]

Last edited by Aakashd; June 26th, 2019 at 10:56 AM.
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  #2  
Old December 28th, 2013, 11:54 AM
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Join Date: Jun 2013
Default Re: CBSE Board Class 12th question papers

Here I am giving you question paper for the class 12th examination organized by the CBSE board of education in PDF files attached with it ..
Some questions are given below :

1.1 Answer the following questions:

a. Even accolades and honours did not change the simple man that
Pasteur was. Why? 2 marks
b. How did Pasteur view those who suffered from diseases? 1 mark
c. How did Pasteur engage himself in the estate? 2 marks
d. What advice did he always give to his pupils? 2 marks
e. How did France, the country of his birth, honour this great scientist? 2 marks

1.2 Find the words from the passage which mean the same as: 3 marks
a. To give up (para 1)
b. People belonging to the same period (para 3)
c. Vote by the people of the country to decide a matter of
national importance (para 6)


Q.3 A.K International School is looking for a receptionist for the school. Write an
advertisement on behalf of the adminstrative officer in the classified columns of
the local newspaper giving necessary details. Draft the advertisement in not more
than 50 words.

OR
Suman/Suresh has cleared the Pre-Medical Pre-Dental entrance examination. The
family is elated at the achievement and they decide to have a get-together for all
friends. Draft an informal invitation for the get-together.

Q.4. You are Shekhar/Tripta a student of A.P Public School. Principals of two schools
from Pakistan visited your school as part of a cultural exchange programme.
Students of the school put up a cultural show in their honour. Write a report about
it for your school magazine. (100-125 words).

OR
As you were driving back home from work you were witness to an accident
between a Maruti car and a truck. The driver of the car was seriously injured.
There was confusion and chaos prevailing on the road. Describe the scene in
about 100 to 125 words. You are Sameer/Samiksha.
Attached Files Available for Download
File Type: pdf CBSE 12TH grade psychology paper.pdf (232.4 KB, 47 views)
File Type: pdf CBSE 12TH grade English paper.pdf (232.4 KB, 49 views)
File Type: pdf CBSE 12TH grade hindi paper.pdf (1.96 MB, 46 views)
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  #3  
Old September 15th, 2015, 10:47 AM
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Default Re: CBSE Board Class 12th question papers

I am the student of class 12th of CBSE and need the previous year question paper of the Biology subject of it for the preparation of exam so can you please provide me this?
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