Madhyamik Examination (WBBSE) - 2018 Life Science (Eng ver)

Madhyamik Examination (WBBSE) - 2018 Life Science (Eng ver)

GROUP—A

1. Write the answer in complete sentence by choosing the correct answer for each question with respective  serial number :      1x15=15

1.1  The tentacles on leaves of an insectivorous plant, called sundew bend to trap the insect as soon as they come  in contact with the insect body, this is—

       (a) Seismonasty      (b) Thermonasty      (c) Photonasty      (d) Chemonasty

1.2  In case of women, the Follicle Stimulating Hormone stimulates the graafian follicle of the ovary to secrete the  hormone is—

      (a) TSH      (b) ADH      (c) Oestrogen       (d) ACTH

1.3  Which one of the following is the correct reflex arc ?

       (a) Receptor → Effector → Efferent nerve → Nerve Centre → Afferent nerve

       (b) Nerve Centre → Receptor → Afferent nerve → Effector → Efferent nerve

       (c) Efferent nerve → Receptor → Afferent nerye → Nerve Centre → Effector

       (d) Receptor → Afferent nerve → Nerve Centre → Efferent nerve → Effector

1.4  In which stage of mitosis cell division, the nuclear membrane and nucleolus are seen to disappear ?

       (a) Anaphase       (b) Prophase       (c) Metaphase        (d) Telophase

1.5  Which of the following is not a structural component of DNA  ?

       (a) Deoxyribose sugar       (b) Uracil base       (c) Thymine base       (d) Phosphoric Acid

1.6  Which one of the following statement is correct regarding sexual repro­duction ?

       (a) Haploid gamete formation is essential in sexual reproduction.

       (b) Sexual reproduction depends only on mitosis

       (c) In sexual reproduction, offsprings could be produced from a single parental organism

       (d) The offsprings, produced in sexual reproduction are genetically identical with parental organism

1.7  Which one of the following is the genotypic ratio at F2 generation of Mendel's monohybrid cross ?

       (a) 1 : 2 : 1       (b) 3 : 1       (c) 9 : 3 : 3 : 1      (d) 2 : 1 : 2

1.8  Which one of the following is not controlled by the autosomal gene of human ?

       (a) Roller tongue       (b) Haemophilia       (c) Thalassaemia       (d) Attached ear lobe

1.9  What would be the phenotypic ratio in the F2 generation of a monohybrid cross in case of incomplete  dominance ?

       (a) 3 : 1       (b) 2 : 1 : 1       (c) 9 : 3 : 3 : 1        (d) 1 : 2 : 1

1.10  Which one of the following is the intraspecific struggle for the same food ?

        (a) struggle between Vulture and Hyaena

        (b) struggle between Eagle and Kite

        (c) struggle among the members of Rohu fish in ponds

        (d) struggle between Egret and Kingfisher

1.11  Which of the following changes did not occur during the course of evolution of horse ?

        (a) Lengthening of limbs

        (b) Increase in the length and thickness of all digits in limbs

        (c) Increase in the length and thickness of only the third digit in limbs

        (d) Increase in size of the whole body

1.12  According to the opinion of the scientists, the pre-biotic environment of the earth that led to the origin of life,  was like—

        (a) Hot dilute soup in the sea water

        (b) Cold thick soup in the sea water

        (c) Cold thick soup in the river water

        (d) Hot thick soup in the ground water

1.13  Which one of the following microbes take part in nitrification ?

         (a) Nitrosomonas        (b) Azotobacter         (c) Pseudomonas        (d) Thiobacillus

1.14  An example of Ex-situ conservation is—

         (a) Sunderban Tiger Reserve project

         (b) Corbet National Park

         (c) Nilgiri Biosphere Reserve

         (d) Cryopreservation

1.15  Which of the following effect is the result of water pollution ?

         (a) Global warming       (b) Eutrophication        (c) Deafness       (d) Bronchitis

GROUP—B

2. Answer 21 questions out of 26 questions given below as instructed:  1x21=21

→ Fill in the blanks with proper words in the following sentences (any five)    1x5=5

    2.1 Due to deficiency of Iodine, the synthesis of —— hormone is hampered.

    2.2 During embryonic development and growth in vertebrates —— cell division takes place.

    2.3 The different —— of Pea Plant many show same phenotype.

    2.4 Homologus organs evolve due to —— evolutlon.

    2.5 The name of one exotic species, that affects the local biodiversity, is ——

    2.6 The fine droplets of smokes, ashes, dusts, pollen grains etc., suspended in air are collectively called ——, which cause various lung diseases.

→ Decide whether the following statements are 'True' or 'False': (any five):   1x5=5

    2.7 Hypothalamus helps to maintain body balance in human.

    2.8 In DNA, Adenine is linked with Guanine with Hydrogen bonds.

    2.9 In his monohybrid cross experiment, Mendel obtained 75% pure tall Pea plants in the first filial generation.

    2.10 In Lamarck's opinion, organisms can acquire any particular inheritable physical trait according to their need.

    2.11 Acid rain is caused by SO2 and NO2 gases formed due to air pollution.

    2.12 Auxin helps the seed to germinate by breaking off dormancy.

→ Match the words in Column-'A' with those which are most appropriate in Column-'B' and rewrite the correct pair mentioning the serial No. of both the columns (any five):       1x5=5

→ Answer in a single word or in a single sentence (any six):  1x6=6

   2.19  Choose the odd one and write it : Dwarfism, Goiter, Thalassaemia, Diabetes Mellitus.

   2.20  Mention one function of lens of human eyeball.

   2.21  A pair of related terms is given below. On the basis of the relationship in the first pair write the suitable word  in the gap of sound pair. Mitosis : Radicle :: —— : Spore Mother cell.

   2.22  In case of guineapig whether the phenotype of the two genotypes bbRR and bbRr is-same ?

   2.23  Write the phenotypic ratio obtained in the F2 generation of Mendel's Dihybrid cross experiment.

   2.24  Mention one adaptation of Sundari plant for salt tolerance.

   2.25  Among the following four terms one includes the other three. Find out that term and write it : Overall knowledge regarding local biological resource, PBR, Traditional belief regarding local biological resource, Sustainable use of local biological resource.

   2.26  Name one endangered animal conserved at Singalila National Park.

GROUP—C

3. Answer any 12 questions in 2-3 sentences out of 17 questions given below:     2x12=24

  3.1  Reflex actions occur when the following incidents happen in everyday life of human. Write the importance of these two reflex actions:

     (a) When food particles enter into the trachea,

     (b) When foreign particles enter inside the nasal cavity.

 3.2  For correction of which defects in vision of eye, spectacles of convex and concave lenses are used ?

 3.3  List the names of the hormones related to following functions :

    ♦ Regulation of sugar level in blood;

    ♦ Stimulation for the secretion of hormones from the Thyroid gland;

    ♦ Causing the growth of Corpus Luteum and stimulating the secretion of Progesterone hormone in the female body;

    ♦ Increasing blood pressure due to anxiety.

 3.4  A resting animal attempts to move. Mention four probable reasons behind it.

 3.5 Distinguish between autosome and sex chromosome of human based on the following features :

      (a) Nature,   (b) Number.

 3.6 What are the processes of asexual reproduction in Spirogyra and Planaria ?

 3.7 Mention two changes related to vision and bones at late adulthood or senescence phase of human  development.

  3.8 With the help of a cross show how the sex of offsprings of human is determined.

  3.9 One day students read an article in newspaper on Thalassemia and were very scared to know the fate of a thalassemic patient. Write what kind of measures they can take to eradicate this disease from the population.

  3.10 What are all probable gametes to be produced from the hybrid plant YyRr produced at F1 generation in a dihybrid cross experiment ?

  3.11 What are the two adaptive significances of airsacs of pigeon ?

  3.12 Write the names of one each vestigeal organ present in vertebral column and alimentary canal in human body.

  3.13 Write in chronological sequence the names of four main fossil ancestors during the course of evolution of the horse.

  3.14 "Nitrogen cycle is affected due to human activities"—state two phenomena to justify it.

  3.15 What would be the environmental consequences as results of recurrent destruction of wetlands and depletion of quantity of agricultural lands ?

  3.16 What are the harmful impacts, sound pollution can exert on the ears and heart in human body ?

  3.17 Mention the roles of biodiversity in the following two aspects in the progress of human civilization:

       (a) Production of foods,   (b) Manufacturing of medicines.

GROUP—D

4. Write the 6 questions or their alternatives given below. Sightless candidates have to answer question no. 4.1(A) instead of question no. 4.1. The mark alloted for each question is 5 (the division of marks is either 3+2, 2+3 or  5) :  5x6=30

   4.1  Draw a diagram of a reflex arc and lebel the following parts— (a) receptor;    (b) Sensory nerve;   (c) Nerve centre;    (d) MotoBnerve. (3+2)

     Or  Draw the morphology of an ideal eukaryotic chromosome and lebel the following parts— (a) Chromatid;   (b) Centromere;     (c) Nucleolar organizer;      (d) Telomere.

   4.2  What types of chemical components are synthesized in different stages of interphase in a cell cycle ?  What might happen if normal control at different points of a cell cycle is lost ? (3+2)

     Or, Depict the alternation of generation in a fern with the help of a flowchart. 'In case of Prophase and Telophase changes of opposite nature happens'— Write two such changes. (3+2)

   4.3  Colour of seed and shape of seed of a pea plant—taking these two characters Mendel performed dihybrid cross. Write the genotypes of pea plants having yellow and round seed produced in the F2 generation of this experiment. State the law of Independent Assortment of Mendel. (2+3)

    Or, State the opposite traits for each of the characters of flowers of pea plant chosen by Mendel for his  experiment. 'For developing the scientific ideas on heredity the experiments performed by Mendel on pea plants are epoch-making.'—Mention three reasons behind his success in performing these experiments.  (2+3)

  4.4 How the special feature of RBC in camels is related to their ability to withstand extreme loss of water ? Give examples of the ways Chimpanzees solve their problems intelligently for procuring food and preventing disease.   (2+3)

   Or, Explain the process of Natural Selection as proposed by Darwin with the help of a suitable example. What are the roles of swim bladder in the aquatic adaptation of Rohu fish ?    (3+2)

   4.5  A lot of indiscriminate activities of humans pollute environment' —Support the statement by giving three examples in favour of it. Give examples of a national park and a biosphere reserve situated in West Bengal.  (3+2)

    Or, Show the steps of Nitrogen Cycle with the help of a flowchart.

   4.6  What environmental factors may cause cancer in human ?  If the water level in sea increases enormously due to global warming, what problems the humans and bio-diversity of Sundarban may face ?   (3+2)

   Or, Mention the in-situ measures adopted for conservation of lion in Gir National Park of India. What environmental problems may arise in a locality due to ever-increasing human population ? (2+3)

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