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12th Standard English Medium Biology Reduced Syllabus One mark Important Questions with Answer key - 2021(Public Exam )

12th Standard

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Biology

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

    Part A

    50 x 1 = 50
  1. The foetal membrane that forms the basis of the umbilical cord is

    (a)

    Allantois

    (b)

    Amnion

    (c)

    Chorion

    (d)

    Yolk sac

  2. Find the wrongly matched pair

    (a)

    Bleeding phase- fall in oestrogen and progesterone

    (b)

    Follicular phase-rise in oestrogen

    (c)

    Luteal phase - rise in FSH level

    (d)

    Ovulatory phase - LH surge

  3. 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 is 2 to 14 days in males and 7 to 21 days in females

    (d)

    Both syphilis and gonorrhoea are easily cured with antibiotics

  4. Haemophilia is more common in males because it is a

    (a)

    Recessive character carried by Y-chromosome

    (b)

    Dominant character carried by Y-chromosome

    (c)

    Dominant trait carried by X-chromosome

    (d)

    Recessive trait carried by X-chromosome

  5. Which of the following phenotypes in the progeny are possible from the parental combination AxB?

    (a)

    A and B only

    (b)

    A,B and AB only

    (c)

    AB only

    (d)

    A,B,AB and O

  6. Father of a child is colourblind and mother is carrier for colourblindness, the probability of the child being colourblind is

    (a)

    25%

    (b)

    50%

    (c)

    100%

    (d)

    75%

  7. “Universal Donor” and “Universal Recipients” blood group are _____and_______respectively

    (a)

    AB, O

    (b)

    O, AB

    (c)

    A, B

    (d)

    B, A

  8. 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

  9. An operon is a:

    (a)

    Protein that suppresses gene expression

    (b)

    Protein that accelerates gene expression

    (c)

    Cluster of structural genes with related function

    (d)

    Gene that switched other genes on or off

  10. 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

  11. Fossils are generally found in

    (a)

    igneous rocks

    (b)

    metamorphic rocks

    (c)

    volcanic rocks

    (d)

    sedimentary rocks

  12. According to Darwin, the organic evolution is due to

    (a)

    Intraspecific competition

    (b)

    Interspecific competition

    (c)

    Competition within closely related species.

    (d)

    Reduced feeding efficiency in one species due to the presence of interfering species.

  13. The Athlete’s foot disease in human is caused by _______

    (a)

    Bacteria

    (b)

    Fungi

    (c)

    Virus

    (d)

    Protozoan

  14. The sporozoite of the malarial parasite is present in ______

    (a)

    saliva of infected female Anopheles mosquito

    (b)

    RBC of human suffering from malaria.

    (c)

    Spleen of infected humans

    (d)

    Gut of female Anopheles mosquito

  15. The most common substrate used in distilleries for the production of ethanol is_________

    (a)

    Soyameal

    (b)

    Groundgram

    (c)

    Molasses

    (d)

    Corn meal

  16. Which of the following bacteria is used extensively as a bio-pesticide?

    (a)

    Bacillus thurigiensis

    (b)

    Bacillus subtilis

    (c)

    Lactobacillus acidophilus

    (d)

    Streptococcus lactis

  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 relationship between sucker fish and shark is__________

    (a)

    Competition

    (b)

    Commensalism

    (c)

    Predation

    (d)

    Parasitism.

  21. Which of the following is considered a hotspots of biodiversity in India

    (a)

    Western ghats

    (b)

    Indo-gangetic plain

    (c)

    Eastern Himalayas

    (d)

    A and C

  22. Which one of the following are at high risk extinction due to habitat destruction

    (a)

    Mammals

    (b)

    Birds

    (c)

    Amphibians

    (d)

    Echinoderms

  23. Which among the following is the most abundant Green-House-Gas (GHG) in the earth’s atmosphere?

    (a)

    Carbon dioxide

    (b)

    Water Vapour

    (c)

    Sulphur Dioxide

    (d)

    Tropospheric Ozone

  24. In the E- waste generated by the Mobile Phones, which among the following metal is most abundant?

    (a)

    Copper

    (b)

    Silver

    (c)

    Palladium

    (d)

    Gold

  25. An eminent Indian embryologist is

    (a)

    S.R.Kashyap

    (b)

    P.Maheswari

    (c)

    M.S. Swaminathan

    (d)

    K.C.Mehta

  26. Arrange the layers of anther wall from locus to periphery

    (a)

    Epidermis,middle layers, tapetum, endothecium

    (b)

    Tapetum, middle layers, epidermis, endothecium

    (c)

    Endothecium, epidermis, middle layers, tapetum

    (d)

    Tapetum, middle layers endothecium epidermis

  27. The scar left by funiculus in the seed is

    (a)

    tegmen

    (b)

    radicle

    (c)

    epicotyl

    (d)

    hilum

  28. 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

  29. Which Mendelian idea is depicted by a cross in which the F1 generation resembles both the parents

    (a)

    Incomplete dominance

    (b)

    Law of dominance

    (c)

    Inheritance of one gene

    (d)

    Co-dominance

  30. Pure tall plants are crossed with pure dwarf plants. In the F1 generation, all plants were tall. These tall plants of F1 generation were selfed and the ratio of tall to dwarf plants obtained was 3:1. This is called

    (a)

    Dominance

    (b)

    Inheritance

    (c)

    Codominance

    (d)

    Heredity

  31. Accurate mapping of genes can be done by three point test cross because increases

    (a)

    Possibility of single cross over

    (b)

    Possibility of double cross over

    (c)

    Possibility of multiple cross over

    (d)

    Possibility of recombination frequency

  32. Genes G S L H are located on same chromosome. The recombination percentage is between L and G is 15%, S and L is 50%, H and S are 20%. The correct order of genes is

    (a)

    GHSL

    (b)

    SHGL

    (c)

    SGHL

    (d)

    HSLG

  33. EcoRI cleaves DNA at

    (a)

    AGGGTT

    (b)

    GTATATC

    (c)

    GAATTC

    (d)

    TATAGC

  34. Which one of the following palindromic base sequence in DNA can be easily cut at about the middle by some particular restriction enzymes?

    (a)

    5' CGTTCG 3' 3' ATCGTA 5'

    (b)

    5'GATATG 3'  3' CTACTA 5'

    (c)

    5'GAATTC 3' 3' CTTAAG 5'

    (d)

    5'CACGTA 3' 3' CTCAGT 5'

  35. An analysis of chromosomal DNA using the southern hybridisation technique does not use

    (a)

    Electrophoresis

    (b)

    Blotting

    (c)

    Autoradiography

    (d)

    Polymerase Chain Reaction

  36. 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.

  37. 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

  38. Virus free plants are developed from

    (a)

    Organ culture

    (b)

    Meristem culture

    (c)

    Protoplast culture

    (d)

    Cell suspension culture

  39. A specific place in an ecosystem, where an organism lives and performs its functions is

    (a)

    habitat

    (b)

    niche

    (c)

    landscape

    (d)

    biome

  40. Read the given statements and select the correct option.
    i) Loamy soil is best suited for plant growth as it contains a mixture of silt, sand and clay.
    ii) The process of humification is slow in case of organic remains containing a large amount of lignin and cellulose.
    iii) Capillary water is the only water available to plant roots as it is present inside the micropores.
    iv) Leaves of shade plant have more total chlorophyll per reaction centre, low ratio of chl a and chl b are usually thinner leaves.

    (a)

    i, ii and iii only

    (b)

    ii, iii and iv only

    (c)

    i, ii and iv only

    (d)

    ii and iii only

  41. Interaction Effects on species X Effects on species Y
    Mutualism A (+)
    B (+) (-)
    Competition (-) C
    D (-) o
    (a)
    A B C D
    (+) Parasitism (-) Amensalism
    (b)
    A B C D
    (-) Mutualism (+) Competition
    (c)
    A B C D
    (+) Competition (0) Mutualism
    (d)
    A B C D
    (O) Amensalism (+) Parasitism
  42. Strong, sharp spines that get attached to animal’s feet are found in the fruits of

    (a)

    Argemone

    (b)

    Ecballium

    (c)

    Heritier

    (d)

    Crossandra

  43. Solar energy used by green plants for photosynthesis is only

    (a)

    2 – 8%

    (b)

    2 – 10%

    (c)

    3 – 10%

    (d)

    2 – 9%

  44. Significance of food web is / are

    (a)

    it does not maintain stability in nature

    (b)

    it shows patterns of energy transfer

    (c)

    it explains species interaction

    (d)

    b and c

  45. Find the wrongly matched pair.

    (a)

    Endemism - Species confined to a region and not found anywhere else.

    (b)

    Hotspots - Western ghats

    (c)

    Ex-situ Conservation - Zoological parks

    (d)

    Sacred groves - Saintri hills of Rajasthan

    (e)

    Alien sp. Of India - Water hyacinth

  46. Deforestation does not lead to

    (a)

    Quick nutrient cycling

    (b)

    soil erosion

    (c)

    alternation of local weather conditions

    (d)

    Destruction of natural habitat weather conditions

  47. While studying the history of domestication of various cultivated plants _______ were recognized
    earlier

    (a)

    Centres of origin

    (b)

    Centres of domestication

    (c)

    Centres of hybrid

    (d)

    Centres of variation

  48. Which of the following is incorrectly paired?

    (a)

    Wheat - Himgiri

    (b)

    Milch breed - Sahiwal

    (c)

    Rice - Ratna

    (d)

    Pusa Komal - Brassica

  49. Find out the correctly matched pair.

    (a)

    Rubber-Shorea robusta

    (b)

    Dye-Lawsonia inermis

    (c)

    Timber-Cyperus papyrus

    (d)

    Pulp-Hevea brasiliensis

  50. The only cereal that has originated and domesticated from the New world.

    (a)

    Oryza sativa

    (b)

    Triticum asetumn

    (c)

    Triticum duram

    (d)

    Zea mays

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