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12th Standard Biology English Medium Free Online Test 1 Mark Questions 2020 - Part Four

12th Standard

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Biology

Time : 00:25:00 Hrs
Total Marks : 25

    Answer all the questions

    25 x 1 = 25
  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: Offsprings produced by asexual reproduction are genetically identical to the parent.
    Reason: Asexual reproduction involves only mitosis and no meiosis

    (a)

    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. Identify the correct option to label the diagram Identify the structure
    1- Immature proglottids
    2 - Gravid proglottids
    3 - Scolex
    4 - Mature proglottids
    5 - Neck

    (a)

    1-C 2-E 3-A 4-D 5-B

    (b)

    1-B 2-D 3-C 4-E 5-A

    (c)

    1-D 2-E 3-B 4-C 5-A

    (d)

    1-A 2-E 3-D 4-B 5-C

  3. ______ is not linked to polymenorrhoea

    (a)

    Shorter cycle

    (b)

    Gland activity

    (c)

    Malnutrition

    (d)

    Pain

  4. Klinefelters’ syndrome is characterized by a karyotype of

    (a)

    XYY

    (b)

    XO

    (c)

    XXX

    (d)

    XXY

  5. A mRNA molecule is produced by

    (a)

    Replication

    (b)

    Transcription

    (c)

    Duplication

    (d)

    Translation

  6. The wings of birds and butterflies is an example of

    (a)

    Adaptive radiation

    (b)

    convergent evolution

    (c)

    divergent evolution

    (d)

    variation

  7. Amphetamines are stimulants of the CNS, whereas barbiturates are ______

    (a)

    CNS stimulant

    (b)

    both a and b

    (c)

    hallucinogenic

    (d)

    CNS depressants

  8. Statement 1: Saccharomyces cerevisiae is commonly called as Baker's yeast.
    Statement 2: Yogurt is produced by the fermentation of milk by Saccharomyces cerevisiae

    (a)

    Statement 1 is correct. Statement 2 is incorrect

    (b)

    Statement 1 is incorrect. Statement 2 is correct

    (c)

    Both the statements 1 and 2 are incorrect

    (d)

    Both the statements 1 and 2 are correct.

  9. Best and Banting isolated insulin from pancreatic islets of___________

    (a)

    E.coli

    (b)

    yeast

    (c)

    dog

    (d)

    pig

  10. Throgh PCR technique, amplication of_________ is possible with reverse transcriptase

    (a)

    DNA

    (b)

    rRNA

    (c)

    tRNA

    (d)

    mRNA

  11. Stirred - tank bioreactors have been designed for

    (a)

    Addition of preservatives of the product

    (b)

    Purification of the product

    (c)

    Ensuring anaerobic conditions in the culture vessel

    (d)

    Availability of oxygen throughout the process

  12. Arrange the steps of PCR in proper sequence

    (a)

    Denaturation, Primer extension, Renaturation

    (b)

    Renaturation, Denaturation, Primer extension

    (c)

    Primer extension, Denaturation, Renaturati

    (d)

    Denaturation, Renaturation, Primer extension

  13. Consider the following four conditions (A-D) and select the correct pair of them as adaptation to environment in desert lizards.
    The conditions:
    A) Burrowing in soil to escape high temperature.
    B) Losing heat rapidly from the body during high temperature
    C) Bask in sun when temperature is low
    D) Insulating body due to thick fatty dermis.

    (a)

    (A) and (C)

    (b)

    (B) and (D)

    (c)

    (A) and (B)

    (d)

    (C) and (D)

  14. Project tiger was first launched in ____________

    (a)

    1973

    (b)

    1978

    (c)

    1999

    (d)

    2001

  15. Ozone is found in the ________ layer of the atmosphere.

    (a)

    Ionosphere

    (b)

    Thermosphere

    (c)

    Stratosphere

    (d)

    Mesosphere

  16. BOD stands for_______

    (a)

    Biological Oxidation Demand

    (b)

    Biotic Oxygen Deficient

    (c)

    Biological Oxygen Deficit

    (d)

    Biochemical Oxidation Deficit

  17. Assertion (A): Carica papaya is a dioecious plant.
    Reason (R): Both male and female flowers are borne on same plant.

    (a)

    A is correct R is incorrect.

    (b)

    R explains A.

    (c)

    Both A and R are incorrect.

    (d)

    Both A and R are correct. R does not explain A.

  18. Observe the diagram and select the correct option mentioning the parts A, B, C and D.

    (a)
    A B C D
    Synergid Egg polar nuclei Antipodals
    (b)
    A B C D
    Antipodals Synergid polar nuclei Egg
    (c)
    A B C D
    Egg Synergid Antipodals polar nuclei
    (d)
    A B C D
    Antipodals polar nuclei Egg Synergid
  19. Result of incomplete dominance is __________

    (a)

    Intermediate genotype

    (b)

    Intermediate phenotype

    (c)

    Recessive phenotype

    (d)

    Epistasis

  20. Micro propagation involves

    (a)

    vegetative multiplication of plants by using micro-organisms.

    (b)

    vegetative multiplication of plants by using small explants.

    (c)

    vegetative multiplication of plants by using microspores.

    (d)

    Non-vegetative multiplication of plants by using microspores and megaspores.

  21. Ecology is the study of an individual species is called
    i) Community ecology
    ii) Autecology
    iii) Species ecology
    iv) Synecology

    (a)

     i only

    (b)

    ii only 

    (c)

     i and iv only

    (d)

    ii and iii only

  22. Which of the following ecosystem has the highest primary productivity?

    (a)

    Pond ecosystem

    (b)

    Lake ecosystem

    (c)

    Grassland ecosystem

    (d)

    Forest ecosystem

  23. With respect to Eichhornia
    Statement A: It drains off oxygen from water and is seen growing in standing water.
    Statement B: It is an indigenous species of our country.

    (a)

    Statement A is correct and Statement B is wrong

    (b)

    Both Statements A and B are correct

    (c)

    Statement A is correct and Statement B is wrong.

    (d)

    Both statements A and B are wrong

  24. Match Column I with Column II
    Column I Column II
    i) William S. Gaud I) Heterosis
    ii) Shull II) Mutation breeding
    iii) Cotton Mather III) Green revolution
    iv) Muller and Stadler IV) Natural hybridization

    (a)

    i – I, ii – II, iii – III, iv – IV

    (b)

    i – III, ii – I, iii – IV, iv – II

    (c)

    i – IV, ii – II, iii – I, iv – IV

    (d)

    i – II, ii – IV, iii – III, iv – I

  25. A wheat variety, Atlas 66 which has been used as a donor for improving cultivated wheat, which is rich in

    (a)

    iron

    (b)

    carbohydrates

    (c)

    proteins

    (d)

    vitamins

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