Half Yearly Model Question Paper - 2019

12th Standard EM

    Reg.No. :
  •  
  •  
  •  
  •  
  •  
  •  

Biology

Time : 02:30:00 Hrs
Total Marks : 70

    Part A

    Answer All Questions

    Choose the most appropriate answer from the four given alternatives and write the option code with the corresponding answer.

    15 x 1 = 15
  1. Assertion and reasoning questions:
    In each of the following questions there are two statements. One is assertion (A) and other is reasoning (R). Mark the correct answer as
    Assertion: In bee society, all the members are diploid except drones.
    Reason: Drones are produced by parthenogenesis

    (a)

    If both A and R are true and R is correct explanation for A

    (b)

    If both A and R are true but R is not the correct explanation for A

    (c)

    If A is true but R is false

    (d)

    If both A and R are false

  2. Assertion (A): The acrosome of the Sperm cell contains Sperm lysin.
    Reason (R): Sperm lysin destroys the deformed Sperm cells.

    (a)

    R explains A

    (b)

    A is right R is wrong

    (c)

    A an R are right R does not explains A

    (d)

    Both A and R are wrong

  3. The approach which does not give the defined action of contraceptive is

    (a)

    Hormonal contraceptive-Prevents entry of sperms, prevent ovulation and fertilization

    (b)

    Vasectomy-Prevents spermatogenesis

    (c)

    Barrier method-Prevents fertilization

    (d)

    Intra uterine device-Increases phagocytosis of sperms, suppresses sperm motility and fertilizing capacity of sperms

  4. DOPA stands for __________

    (a)

    3,4 - dihydroxy phenyl acetate

    (b)

    3,4 - dihydroxy phenyl alanine

    (c)

    3,4 - dihydroxy phenyl asparate

    (d)

    3,4 - dihydroxy phenyl aldehyde

  5. A mRNA molecule is produced by

    (a)

    Replication

    (b)

    Transcription

    (c)

    Duplication

    (d)

    Translation

  6. Theory of chemical evolution was proposed by ___________________

    (a)

    Stanley

    (b)

    Urey

    (c)

    Lamarck

    (d)

    Wiessmann

  7. One after following statement is wrong. Find out.
    I Bhang affects the cardiovascular system
    II Opium acts a depressent on the central nervous system
    III Lysergic acid diethylamide distorts the wayone sees, hears and feels
    IV Barbiturates slows down the activity of the 4. brain.

    (a)

    I II IV

    (b)

    II IV

    (c)

    all the above

    (d)

    none of the above

  8. CO2 is not released during

    (a)

    Alcoholic fermentation

    (b)

    Lactate fermentation

    (c)

    Aerobic respiration in animals

    (d)

    Aerobic respiration in plants

  9. Pick out the eurythermal organism

    (a)

    Fish

    (b)

    Frog

    (c)

    Tiger

    (d)

    Lizards

  10. Which of the following forests is known as the lungs of the planet earth?

    (a)

    Tundra forest

    (b)

    Rain forest of north east India

    (c)

    Taiga forest

    (d)

    Amazon rain forest

  11. A Plant called X possesses small flower with reduced perianth and versatile anther. The probable agent for pollination would be

    (a)

    water

    (b)

    air

    (c)

    butterflies

    (d)

    beetles

  12. Which of the following statement is correct

    (a)

    Agar is not extracted from marine algae such as seaweeds

    (b)

    Callus undergoes differentiation and produces somatic embryoids.

    (c)

    Surface sterilization of explants is done by using mercuric bromide

    (d)

    PH of the culture medium is 5.0 to 6.0

  13. Assertion (A) : Plains and valleys are rich in vegetation
    Reason (R): Slow drain of surface water and better water retention is noticed.

    (a)

    A is true R is false

    (b)

    R explains A

    (c)

    A and R are false

    (d)

    A and R are true. But R doesnot explains A

  14. Identify the plant species that is not used as a live fence.

    (a)

    Sesbania grandiflora

    (b)

    Acacia species

    (c)

    Petunia species

    (d)

    Erythrina species

  15. Allergy involves

    (a)

    IgE

    (b)

    IgG

    (c)

    IgA

    (d)

    IgM

  16. Part B

    Answer any SIX questions. Question number 24 is compulsory

    6 x 2 = 12
  17. What is parthenogenesis? Give two examples from animals.

  18. What are non-sense codons?

  19. List out the major gases seems to be found in the primitive earth.

  20. Name any four antibiotics

  21. Name few endangered species protected in Arignar Anna Zoological Park.

  22. Name any four chemical mutagens.

  23. Mention the way by which culture media and explants are sterilized.

  24. Mention any two free-living nitrogen-fixing bacteria.

  25. Give definitions for organic farming?

  26. Part C

    Answer any SIX questions. Question number 33 is compulsory

    6 x 3 = 18
  27. The unicellular organisms which reproduce by binary fission are considered immortal. Justify

  28. Mention the importance of the position of the testes in humans.

  29. Complete the table by filling the gaps.

    Disease Causative agent Symptoms
    Gonnorrhea A Affects urethra & cervix, painful urination
    B Human Immuno Virus Enlarged lymph node, night sweat, weight
    reduction
    Hepatitis Hepatitis-B- Virus C
  30. Point out any four conditions under which Hardy Weinberg's equilibrium is not attained.

  31. Explain co-mutagens with examples.

  32. How will you identify a vectors?

  33. What are Secondary metabolites? Give example.

  34. List any two adaptive features evolved in parasites enabling them to live successfully on their host?

  35. Name of the food chain which is generally present in all type of ecosystem. Explain and write their significance.

  36. Part D

    Answer All Questions 

    5 x 5 = 25
    1. Describe the various stages of decomposition process.

    2. What are the King and Queen of spices? Explain about them and their uses.

    1. With a suitable diagram explain the structure of an ovule.

    2. Differentiate continuous variation with discontinuous variation.

    1. How primary immune response differ from secondary immune response?

    2. Write the characteristics of tundra.

    1. Write the preventive measures of STDs.

    2. What is co evolution?

    1. Write notes on binary fission in animals.

    2. The following is the illustration of the sequence of ovarian events (a-i) in a human female.

      a) Identify the figure that illustrates ovulation and mention the stage of oogenesis it represents.
      b) Name the ovarian hormone and the pituitary hormone that have caused the above-mentioned events.
      c) Explain the changes that occurs in the uterus simultaneously in anticipation.
      d) Write the difference between C and H.

*****************************************

TN 12th Standard EM Biology free Online practice tests

Reviews & Comments about 12th Biology - Half Yearly Model Question Paper 2019

Write your Comment