CBSE Set Q Biology Sample Test Papers For Class 12th for students online
You are on questions of Section A,B,C,D
Max Marks : 70
Time allowed : 3 hrs
Q. Nos. 1-8 are of very short answer type carrying one mark each. Answer them in 1-20 words each.
Q1. Name the process in which
bacteriophage picks-up a piece of DNA from one bacterial cell and transfers the
same to another bacterial cell on infection.
Q2. Which fraction of soil water is
readily available to plants for absorption?
Q3. What protects nitrogenase?
Q4. Name two plants that produce
Q5. Why is oxytocin called as
Q6. From which germ layers do the
following organs differentiate :
(ii) Urinary bladder
Q7. What provides energy for abiotic
synthesis on the primitive earth?
Q8. Name the two curable sexually transmitted diseases.
Q. Nos. 9-18 are short answer questions carrying 2 marks each. It is appropriate to answer them in about 20-30 words.
Q9. In most plants the terminal bud
suppresses the development of lateral buds. What is this phenomenon called? Name
the phytohormone that can promote the phenomenon.
Q10. Sieve tubes in angiosperms are
associated with specialised parenchyma cells. Name those cells. How do they help
sieve tube members?
Q11. How is the digested fat
Q12. What are antagonistic muscles?
Give one example.
Q13. Describe the methods of birth
control by which fertilisation of ovum by sperm is prevented.
Q14. What is artificial selection in
terms of evolution? Name one plant that has been produced as a result of
Q15. ‘Birds have evolved from
reptiles’. How does palaentology provide evidence in support of the above
Q16. Who discovered the coacervates?
List the biological properties of co-acervates.
Q17. What is mycorrhiza? How does it
act as biofertiliser?
Q18. Define autoimmune diseases.
Give two examples.
Q. Nos. 19-27 are short answer questions carrying 3 marks each. It is appropriate to answer them in about 30-50 words.
Q19. What is transformation?
Describe Griffith’s transformation experiment.
Q20. What are linked genes? Diagrammatically represent a cross between a white eyed female and red eyed male drosophila.
Q21. How does an excess of
tryptophan cause ‘Switching off’ of the ‘tryptophan operon’?
Q22. If abiotic origin of life is in
progress on a planet other than earth, what should be the condition there?
Q23. Trace the formation of Ovum
Q24. Describe the role of red blood
cells in the transport of oxygen and carbon dioxide by blood.
Q25. Draw a diagram to show the
internal structure of the human heart. Label six parts in all including at least
Q26. What is metastasis? List any
four danger signals of cancer.
Q27. By providing one example for
each category, classify the angiospermic flowers based on the position of ovary.
Q. Nos. 28 – 30 are long answer questions carrying 5 marks each. It is appropriate to answer them in about 80 – 120 words each.
Q28. Describe the process of DNA
Q29. Specify how C4
photosynthetic pathway increases CO2 concentration in
bundle sheath cells of sugarcane. How much is C4 pathway
more energy-expensive than C3 pathway?
Q30. What is a synapse? How is the
nerve impulse transmitted across a synapse?