CBSE Set Q Biology Sample Test Papers For Class 12th for students online
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Time allowed : 3 hrs
Question Nos. 1-8 are of very short
answer type carrying 1 mark each only.
Answer them in 1-20 words each.
Q1. At what stage is the embryo
implanted in the uterus of the mother in the case of a test tube baby?
Q2. Human heart is Myogenic yet a
parasympathetic nerve can reduce the heart rate. Name the nerve.
Q3. Which of the following diseases
could be avoided by analysing the pedegree of parents –
Klinefelter’s syndrome, Haemophilia, Amoebiasis.
Q4. Name the functional contractile
unit of the muscle.
Q5. Name any two synthetic auxins
used in agriculture.
Q6. What is pulvinus?
Q7. Name the fluid in which the
membranous labyrinth of the inner ear floats.
Q8. In a round worm the volume of
the body increases due to the growth of the body cells without increase in their
number. What do you call this type of growth?
Question Nos. 9 – 18 are short
answer questions carrying 2 marks each.
It is appropriate to answer them in about 20 – 30 words.
Q9. Why is the cleavage in mammals
referred to as simple holoblastic?
Q10. Name the tissue that lines the
urinary bladder. State any one advantage of this tissue being present there.
Q11. Draw a labelled diagram of the
vertical section of an apple.
Q12. Why is the human male referred
to as heterogametic?
Q13. What are the events that take
place at the point of stimulation of an axon?
Q14. Write the transcribed m-RNA
from the DNA strand with the base sequence of TAG TAC ACT. What is the specific
term used for the last codon of the transcribed m-RNA in this case?
Q15. Why is blood group
identification not required while transfusing serum?
Q16. The primitive earth had
reducing atmosphere to enable abiotic origin of life. What put an end to it?
Q17. How does a sickle-cell carrier
have an advantage over the rest of the human population in a Malaria ridden
Q18. What acts as an inducer in Lac
Operon? How does it switch on the operon?
Question Nos. 19 – 27 are short
answer questions carrying 3 marks each.
It is appropriate to answer them in about 30 – 50 words.
Q19. A Chrysanthemum plant with
floral buds requires more than 12 hours of dark night time to flower. If the
night is interrupted by white light for duration of an hour, will the flowers
bloom the following morning?
Name the pigment that perceives the light stimulus for flowering.
Where is the pigment present in the plant and what are its two forms?
Q20. Define cancer. How are cancers
broadly classified pathologically? Name one major cancer in women and one major
cancer in men in India.
Q21. State Lamarck’s theory on
evolution. Who disproved it and how?
Q22. A farmer has been advised to
sow Soyabean seeds inoculated with a bacterial culture. Name the bacterium in
the culture. How is this bacterium useful to the crop?
Q23. Draw a labelled diagram showing
the longitudinal section of the phloem of an angiosperm with its components.
Q24. Name any three organs
homologous to human hand. Why are they considered homologous?
Q25. Give the full form of ADH. Name
the gland that secretes it. Under what condition of the body is it released?
What is its role in forming hypertonic urine? What disease is caused due to the
failure of secretion of this hormone?
Q26. Give one reason why lysozyme is
considered an enzyme and not a hormone? How does it defend the body? Name any
two secretions in humans, which contain lysozyme.
Q27. Draw a schematic diagram to
show the continuous and discontinuous synthesis of DNA and label it.
Question Nos. 28 – 30 are long
answer questions carrying 5 marks each.
It is appropriate to answer them in about 80 – 120 word each.
Q28. Where does spermatogenesis take
place? Describe the stages of the process.
Q29. Where does cyclic
photophosphorylation occur in the leaves? Explain the events in sequence. Why is
the process referred to as cyclic?
Q30. Differentiate between linkage
and sex-linked inheritance. Describe the mode of inheritance of any one
sex-linked trait in humans.