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12th Standard Zoology English Medium Free Online Test One Mark Questions with Answer Key 2020

12th Standard

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Zoology

Time : 00:20:00 Hrs
Total Marks : 20

    Answer all the questions

    20 x 1 = 20
  1. During favourable conditions ______ shows multiple fission.

    (a)

    Plasmodium

    (b)

    Amoeba

    (c)

    Planaria

    (d)

    Euglena

  2. Regeneration was first studied by _______

    (a)

    A.G. Tansley

    (b)

    Charles Bonnet

    (c)

    Abraham Trembley

    (d)

    Walter Gilbert

  3. Mammalian egg is

    (a)

    Mesolecithal and non cleidoic

    (b)

    Microlecithal and non cleidoic

    (c)

    Alecithal and non cleidoic

    (d)

    Alecithal and cleidoic

  4. _____ may be due to cancer of the ovary.

    (a)

    Amenorrhoea

    (b)

    Dysmenorrhoea

    (c)

    Menorrhagia

    (d)

    Oligomenorrhoea

  5. The _____ contractions lead to false labour pains.

    (a)

    Let - Down reflex

    (b)

    Ferguson reflex

    (c)

    Foetal ejection reflex

    (d)

    Braxter - Hicks

  6. Which is not a correct statement regarding Oogenesis?
    (i) During foetal development, cells in germinal epithelium of foetal ovary undergo mitosis and produce oogonia.
    (ii) Oogonial cell divide and enter into prophase I of meiosis I and from primary oocytes.
    (iii)Primary oocytes later develop into primary follicles.
    (iv) No oogonia is formed or added after the foetal birth.

    (a)

    Only i

    (b)

    ii and iii

    (c)

    iv only

    (d)

    None of the above

  7. A contraceptive pill prevents ovulation by

    (a)

    blocking fallopian tube

    (b)

    inhibiting release of FSH and LH

    (c)

    stimulating release of FSH and LH

    (d)

    causing immediate degeneration of released ovum.

  8. ______ is observed as world population day

    (a)

    11th June

    (b)

    11th April

    (c)

    11th July

    (d)

    11th May

  9. What can be the blood group of offspring when both parents have AB blood group?

    (a)

    AB only

    (b)

    A, B and AB

    (c)

    A, B, AB and O

    (d)

    A and B only

  10. X chromosomes was discovered by _________.

    (a)

    Landsteiner

    (b)

    Henking

    (c)

    Stevens

    (d)

    Bridges

  11. Assertion (A): On diagnosis, Ramu is reported to have underdeveloped testis and gynaecomastia.
    Reason (R): His karyotype reveals XXY condition

    (a)

    A is right but R is wrong

    (b)

    R explains A

    (c)

    Both A and R are wrong

    (d)

    Both and R are right but R is not the correct explanation of A

  12. What is the basis for the difference in the synthesis of the leading and lagging strand of DNA molecules?

    (a)

    Origin of replication occurs only at the 5' end of the molecules

    (b)

    DNA ligase works only in the 3' → 5' direction

    (c)

    DNA polymerase can join new nucleotides only to the 3' end of the growing stand.

    (d)

    Helicases and single-strand binding proteins that work at the 5' end

  13. There are no tRNA, for _______ codons.

    (a)

    AUG

    (b)

    GUC

    (c)

    UAA

    (d)

    AGA

  14. Which of the following sequence has completely translated?
    (i) AGA, UUU, UGU, AGU, UAG
    (ii) AUG, UUU, AGA, UAC, UAA
    (iii) AAA, UUU, UUG, UGU, UGA
    (iv) AUG, AAU, AAC, UAU, UAG

    (a)

    i and ii

    (b)

    ii only

    (c)

    i and iii

    (d)

    ii and iv

  15. Who proposed the Germplasm theory?

    (a)

    Darwin

    (b)

    August Weismann

    (c)

    Lamarck

    (d)

    Alfred Wallace

  16. _________________ era is called age of mammals

    (a)

    Precambrian

    (b)

    Permian

    (c)

    Cenozoic

    (d)

    Paleozoic

  17. Choose the correctly match pair.

    (a)

    Amphetamines - Stimulant

    (b)

    LSD - Narcotic

    (c)

    Heroin - Psychotropic

    (d)

    Benzodiazepine - Pain killer

  18. Vector control research Centre is located in__________

    (a)

    Chennai

    (b)

    Delhi

    (c)

    Puducherry

    (d)

    Hyderabad

  19. Transgenic animals are those which have

    (a)

    Foreign DNA in some of their cells

    (b)

    Foreign DNA in all their cells

    (c)

    Foreign RNA in some of their cells

    (d)

    Foreign RNA in all their cells

  20. Who introduced the term biodiversity?

    (a)

    Edward Wilson

    (b)

    Walter Rosen

    (c)

    Norman Myers

    (d)

    Alice Norman

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