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Life Science Question Paper 2018

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Group A

1.Multiple choice question.
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 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 are?
(a) Receptor → Effector → Efferent nerve → Nerve centre → Afferent nerve
(b) Nerve centre → Receptor → Afferent nerve → Effector → Efferent nerve
(c) Efferent nerve → Receptor → Afferent nerve → 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 statements 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, offspring 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 F2generation 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) Hemophilia
(c) Thalassemia
(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
(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 pond
(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 prebiotic Environment of the earth that led to the origin of life was like —
(a) Hot dilute. soup in tie sea water
(b) Cold dilute soup in the sea water
(c) Cold dilute soup in the river water
(d) Hot dilute soup in the ground water

1.13 Which one of the following microbes take part in nitrification?
(a) Nitrosomonas
(b) Azotobacter
(c) Pseudomonas

1.14 An’ example of Ex-situ conservation is
(a) Sundarbans Tiger Reserve
(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 any 21 question out of 26 questions given below as instructed: –
Fill in the blanks with proper words in the following sentences (any five): –

2.1 Due to deficiency of Iodine, the synthesis of hormone is hampered.
2.2 During embryonic development and growth in vertebrates ____cell division take place.
2.3 The different of Pea Plant may show same Phenotype.
2.4 Homologues organs evolve due to____evolution.
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 collectively called____, which cause various lung diseases.

Decide whether the following statements are true or false (any five)
2.7 Hypothalamus helps to maintain body balance in human.
2.8 In DNA, Adenine is linked with Guanine by 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 of dormancy.

Match the right column with the left column: (Any five):

Column AColumn B
2.13) CSFa) Large colloidal aggregates
2.14) Crossing overb) Active participation of local peoples for restoration
of forests
2.15) Haemophiliac) Meiosis
2.16) Coacervated) Movement of daughter chromosome towards the pole
2.17) JFMe) Disorder caused by recessive gene located at human
X- chromosome.
2.18) Graftingf) Supplies to brain cells
 g) Stock scion

Answer in a single word or in a single sentence (any six) :

2.19 Choose the odd one and write, it:
Dwarfism, Goiter, Thalassemia, 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 second 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:

3.1 Reflex actions occur when the following incidents- happen in everyday life of human. Write the importance of these two reflex actions.
When food particles enter into the trachea
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.

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 humans 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 air sacs of pigeon?

3.12 Write the names of one each vestigial 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:
Production of foods
Manufacturing of medicines


4. Answer 6 questions or their alternatives given below.
4.1 Draw a diagram of a reflex arc and label the following parts:
(a) Receptor (b) Sensory nerve (c) Nerve center (d) Motor nerve
Draw the morphology of an ideal eukaryotic chromosome and label 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?
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.

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

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.
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?

4.5 “A lot of indiscriminate activities of humans pollute environment”— Support the statement by giving three, examples in favor of it. Give examples of a national part and a biosphere reserve situated. in West Bengal.
Show the steps of Nitrogen Cycle With the help of a flowchart.

4.6 What environmental factors may cause cancer, inhuman? If the water level in the sea increases enormously due to global warming; what problems the humans and the bio-diversity of Sundarbans may face?
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 the ever-increasing human population



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