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12th Standard Biology Important 1 Mark Questions

12th Standard

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Biology

Time : 01:00:00 Hrs
Total Marks : 50

    Answer all the following questions.

    50 x 1 = 50
  1. The mode of sexual reproduction in bacteria is by ______.

    (a)

    Formation of gametes

    (b)

    Endospore formation

    (c)

    Conjugation

    (d)

    Zoospore formation

  2. The male sex hormone testosterone is secreted from _____.

    (a)

    Sertoli cells

    (b)

    Leydig cell

    (c)

    Epididymis

    (d)

    Prostate gland

  3. The glandular accessory organ which produces the largest proportion of semen is ______.

    (a)

    Seminal vesicle

    (b)

    Bulbourethral gland

    (c)

    Prostate gland

    (d)

    Mucous gland

  4. The milk secreted by the mammary glands soon after child birth is called ______.

    (a)

    Mucous

    (b)

    Colostrum

    (c)

    Lactose

    (d)

    Sucrose

  5. Identify the correct statements from the following.

    (a)

    Chlamydiasis is a viral disease

    (b)

    Gonorrhoea is caused by a spirochaete bacterium, Treponema palladium

    (c)

    The incubation period for syphilis is 2 to 14 days in males and 7 to 21 days in females

    (d)

    Both syphilis and gonorrhoea are easily cured with antibiotics

  6. Select the incorrect action of hormonal contraceptive pills from the following

    (a)

    Inhibition of spermatogenesis.

    (b)

    Inhibition of ovulation

    (c)

    Changes in cervical mucus impairing its ability to allow passage and transport of sperms

    (d)

    Alteration in uterine endometrium to make it unsuitable for implantation

  7. ABO blood group in man is controlled by _____.

    (a)

    Multiple alleles

    (b)

    Lethal genes

    (c)

    Sex linked genes

    (d)

    Y-linked genes

  8. 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

  9. Hershey and Chase experiment with bacteriophage showed that ______.

    (a)

    Protein gets into the bacterial cells

    (b)

    DNA is the genetic material

    (c)

    DNA contains radioactive sulphur

    (d)

    Viruses undergo transformation

  10. E. coli cell grown on 15N medium are transferred to 14N medium and allowed to grow for two generations. DNA extracted from these cells is ultracentrifuged in a cesium chloride density gradient. What density distribution of DNA would you expect in this experiment?

    (a)

    One high and one low density band

    (b)

    One intermediate density band.

    (c)

    One high and one intermediate density band.

    (d)

    One low and one intermediate density band

  11. Which of the following was the contribution of Hugo de Vries?

    (a)

    Theory of mutation

    (b)

    Theory of natural Selection

    (c)

    Theory of inheritance of acquired characters

    (d)

    Germplasm theory

  12. Which period was called “Age of fishes”?

    (a)

    Permian

    (b)

    Triassic

    (c)

    Devonian

    (d)

    Ordovician

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

    (a)

    CNS stimulant

    (b)

    both a and b

    (c)

    hallucinogenic

    (d)

    CNS depressants

  14. Allergy involves

    (a)

    IgE

    (b)

    IgG

    (c)

    lgA

    (d)

    IgM

  15. Cyclosporin – A is an immunosuppressive drug produced from _______

    (a)

    Aspergillus niger

    (b)

    Manascus purpureus

    (c)

    Penicillium notatum

    (d)

    Trichoderma polysporum

  16. The gases produced in anaerobic sludge digesters are

    (a)

    Methane, oxygen and hydrogen sulphide

    (b)

    Hydrogen sulphide, methane and sulphur dioxide

    (c)

    Hydrogen sulphide, nitrogen and methane

    (d)

    Methane, hydrogen sulphide and CO2.

  17. The genetic defect adenosine deaminase deficiency may be cured permanently by

    (a)

    Enzyme replacement therapy

    (b)

    periodic infusion of genetically engineered lymphocytes having ADA cDNA

    (c)

    administering adenosine deaminase activators

    (d)

    introducing bone marrow cells producing ADA into embryo at an early stage of development.

  18. 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

  19. Predation and parasitism are which type of interactions?

    (a)

    (+,+)

    (b)

    (+, O)

    (c)

    (--, --)

    (d)

    (+, --)

  20. The organization which published the red list of species is

    (a)

    WWF

    (b)

    IUCN

    (c)

    ZSI

    (d)

    UNEP

  21. Assertion(A): The Environmental conditions of the tropics are favourable for speciation and diversity of organisms.
    Reason(R): The climate seasons, temperature, humidity and photoperiod are more or less stable and congenial.

    (a)

    Both Assertion and Reason are true and Reason explains Assertion correctly.

    (b)

    Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

    (c)

    Assertion is true, but Reason is false.

    (d)

    Both Assertion and Reason are false.

  22. SMOG is derived from:

    (a)

    Smoke

    (b)

    Fog

    (c)

    Both (a) and (b)

    (d)

    Only A

  23. Pollen tube was discovered by ______.

    (a)

    J.G.Kolreuter

    (b)

    G.B.Amici

    (c)

    E.Strasburger

    (d)

    E.Hanning

  24. Which one of the following is an example of polygenic inheritance?

    (a)

    Flower colour in Mirabilis Jalapa

    (b)

    Production of male honey bee

    (c)

    Pod shape in garden pea

    (d)

    Skin Colour in humans

  25. An allohexaploidy contains ______.

    (a)

    Six different genomes

    (b)

    Six copies of three different genomes

    (c)

    Two copies of three different genomes

    (d)

    Six copies of one genome

  26. pBR 322, BR stands for ______.

    (a)

    Plasmid Bacterial Recombination

    (b)

    Plasmid Bacterial Replication

    (c)

    Plasmid Boliver and Rodriguez

    (d)

    Plasmid Baltimore and Rodriguez

  27. 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.

  28. Cryopreservation means it is a process to preserve plant cells, tissues or organs _____.

    (a)

    at very low temperature by using ether.

    (b)

    at very high temperature by using liquid nitrogen

    (c)

    at very low temperature of -196°C by using liquid nitrogen

    (d)

    at very low temperature by using liquid nitrogen

  29. Which of the given plant produces cardiac glycosides?

    (a)

    Calotropis

    (b)

    Acacia

    (c)

    Nepenthes

    (d)

    Utricularia

  30. Which of the following plant has a non-succulent xerophytic and thick leathery leaves with waxy coating

    (a)

    Bryophyllum

    (b)

    Ruscus

    (c)

    Nerium

    (d)

    Calotropis

  31. Profundal zone is predominated by heterotrophs in a pond ecosystem, because of ______.

    (a)

    with effective light penetration

    (b)

    no effective light penetration

    (c)

    complete absence of light

    (d)

    a and b

  32. Which of the following are not regulating services of ecosystem services
    i) Genetic resources
    ii) Recreation and aesthetic values
    iii) Invasion resistance
    iv) Climatic regulation

    (a)

    i and iii 

    (b)

     ii and iv

    (c)

    i and ii

    (d)

    i and iv

  33. Which of the following would most likely help to slow down the greenhouse effect.

    (a)

    Converting tropical forests into grazing land for cattle.

    (b)

    Ensuring that all excess paper packaging is buried to ashes.

    (c)

    Redesigning landfill dumps to allow methane to be collected.

    (d)

    Promoting the use of private rather than public transport.

  34. Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancer?

    (a)

    Ammonia

    (b)

    Methane

    (c)

    Nitrous oxide

    (d)

    Ozone

  35. 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 ii iii iv
    I II III IV
    (b)
    i ii iii iv
    III I IV II
    (c)
    i ii iii iv
    IV II I IV
    (d)
    i ii iii iv
    II IV III I
  36. Match column I (crop) with column II (Corresponding disease resistant variety) and select the correct option from the given codes.

    Column I Column II
    I) Cowpea i) Himgiri
    II) Wheat ii) Pusa komal
    III) Chilli iii) Pusa Sadabahar
    IV) Brassica iv) Pusa Swarnim
    (a)
    I II III IV
    iv iii ii i
    (b)
    I II III IV
    ii i iii iv
    (c)
    I II III IV
    ii iv i iii
    (d)
    I II III IV
    i iii iv ii
  37. Assertion: Vegetables are important part of healthy eating.
    Reason: Vegetables are succulent structures of plants with pleasant aroma and flavours.

    (a)

    Assertion is correct, Reason is wrong

    (b)

    Assertion is wrong, Reason is correct

    (c)

    Both are correct and reason is the correct explanation for assertion.

    (d)

    Both are correct and reason is not the correct explanation for assertion.

  38. Find out the correctly matched pair.

    (a)

    Rubber-Shorea robusta

    (b)

    Dye-Lawsonia inermis

    (c)

    Timber-Cyperus papyrus

    (d)

    Pulp-Hevea brasiliensis

  39. Anaphylactic shock is due to

    (a)

    Allergic reaction

    (b)

    Secretion of toxins

    (c)

    Secretion of histamines

    (d)

    All the above

  40. B cells that produce and release large amounts of antibody are called

    (a)

    Memory cells

    (b)

    Basophils

    (c)

    Plasma cells

    (d)

    killer cells

  41. Multiple fission is seen in _______

    (a)

    Vorticella and ceratium

    (b)

    Plasmodium and paramecium

    (c)

    Amoeba and cyanobacteria

    (d)

    Vorticella and plasmodium

  42. This technique is used to diagnose the chromosomal abnormities.

    (a)

    Assisted Reproductive Technology (ART)

    (b)

    Micro Testicular Sperm Extraction

    (c)

    Amniocentesis

    (d)

    GIFT

  43. Height in humans is 

    (a)

    Somatagenic variation

    (b)

    Discontinuous variation

    (c)

    Continuous variation

    (d)

    Both B and C

  44. DB is a standard abbreviation  used for the quantitative expression of

    (a)

    The density of bacteria in a medium

    (b)

    A particular pollutant

    (c)

    The dominant bacillus in a culture

    (d)

    A certain pesticide

  45. A scrubber in the exhaust of a chemical industrial plant removes

    (a)

    Gases like sulphur dioxide.

    (b)

    Particulate matter of the size 5 micrometer or above.

    (c)

    Gases like ozone and methane

    (d)

    Particulate matter of the size 2.5 micrometer or less

  46. An ovule which becomes curved so that the nucellus and embryo sac lie at right angles to the funicle is

    (a)

    camdylotropous

    (b)

    anatropous

    (c)

    orthotropous

    (d)

    hemianatropous

  47. In order to calculate map distance of genes on a chromosome, this has to be considered

    (a)

    Number of mutant genes

    (b)

    Cross over percentage

    (c)

    Recombination frequency of each gene locus

    (d)

    Non cross over percentage

  48. _____________ technique helps in identification of transformed cells in culture media.

    (a)

    Blue white colony selection

    (b)

    Antibiotic resistant markers

    (c)

    Replica plating

    (d)

    Agarose gel electrophoresis

  49. If we uncover half of the forest covering the earth, what crisis will be produced at most and the first?

    (a)

    Some species will be extinct

    (b)

    Population and ecological imbalance will rise up

    (c)

    Energy crisis will occur

    (d)

    Rest half forests will maintain this imbalance

  50. Which plant in cultivated for about 7,500 years?

    (a)

    Oryza sativa

    (b)

    Triticum aestivum

    (c)

    Secale cerale

    (d)

    Chenopodium

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