Life Science 2023: WBBSE Class 10 Question Paper

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Get all old/previous years question paper of West Bengal Board (WBBSE) Class 10 (HSLC/Madhyamik) on our website for the students. In this post, we’ve provided for you the Life Science 2023 WBBSE Class 10 question paper. Scroll down to bottom to get the question papers of other subjects and other years or to get solutions of different subjects in both English and Medium.

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2023

LIFE SCIENCE

DIRECTIONS

Regular Candidates will answer questions from Groups A, B, C and D. External candidates will answer questions from Group E.

(Special Instructions for visually handicapped candidates) Answer Question 4.1 (A) instead of Question 4.1 in Group D. Instruction on how many questions from a group must be attempted is provided in the beginning of the group. 

GROUP-‘A’

(Answer to all questions is compulsory)

1. Choose the correct answer for each question and write it with its respective-serial number  1×15=15 

1.1 Which of the following is not a structural feature of Axon? 

(a) Node of Ranvier
(b) Myelin sheath
(c) Nissl granule 
(d) Schwann cell 

1.2 Which of the following is a function of the hormone ADH? 

(a) Increases blood pressure by constricting arterioles 
(b) Helps in the production of sperm and ovum in adult life
(c) Converts glucose into glycogen and stores in hepatic and muscle cells
(d) Causes development of the nervous system and maintains its normal function

1.3 Cornea, Choroid, Lens, Aqueous humor, Iris, Vitreous humor – how many of these are refractory media of the eye ball?

(a) 3
(b) 4
(c) 5
(d) 6

1.4 Which of the following is correct regarding the Chemical Composition of nucleotide ?

(a) 5 -C Sugar + Phosphoric Acid = Nucleotide
(b) Nitrogenous base + Phosphoric Acid = Nucleotide –
(c) 5 C Sugar + Nitrogenous base = Nucleotide
(d) 5 C Sugar + Nitrogenous base + Phosphoric Acid = Nucleotide

1.5 Which of the following pair is correct in respect of the process of cross pollination?

Mode of Pollination	Name of the plant
(a) Anemophilous	Mango
(b) Hydrophilous	paddy
(c) Entomophilous	Hydrilla
(d) Ornithophilous	Butea/Palash/flameof the forest

1.6 Which of the following stages is not included under the Sporophyte generation in the alternation of generations of the fern?

(a) Prothallus
(b) Sorus
(c) Sporangium
(d) Spore mother cell

1.7 What is the ratio of the number of the genotypes BbRr and BBRR generation of dihybrid cross in Guineapig

(a) 2:1 
(b) 4:1
(c) 1:2
(d) 1:1

1.8 Which two of the following genotypes represent the genotype of pea plan with yellow coloured and wrinkled seed? 

(a) YYrr, Yyrr 
(b) YYRr, YyRR 
(c) yyRR, yyRr 
(d) YYRR, yyrr

1.9 Which would be the genotypic and phenotypic ratio in the p generation ol hybrid cross in case of incomplete dominance? 

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

1.10 Which of the following is not a tenet of Darwinism? 

(a) Inheritance of acquired character
(b) Struggle for existence
(c) Variation
(d) Natural selection

1.11 Identify the features of homologous organs-

(a) Different by structure but identical by origin and function 
(b) Different by origin and function but identical by structure 
(c) Different by origin but identical by structure and function 
(d) Identical by origin and structure but different by function 

1.12 Which reactants were used in the experiment of Miller and Urey regarding chemical origin of life?

(a) Oxygen, Methane, Nitrogen dioxide 
(b) Water, Methane, Ammonia, Hydrogen
(c) Methane, Hydrogen sulphide, Carbon monoxide
(d) Nitrous oxide, Methane, Carbon dioxide

1.13 Identify the correct sequence of Nitrogen Cycle

(a) Fixation of Nitrogen → Denitrification → Ammonification → Nitrification
(b) Ammonification → Nitrification Nitrogen Fixation → Denitrification
© Nitrogen Fixation Ammonification → Nitrification → Denitrification
(d) Nitrification Nitrogen Fixation Denitrification→ Ammonification

1.14 Decide which of the following pair of cause of depletion and victimised species is correct regarding depletion of biodiversity 

(a) Introduction of exotic specie → One-horned Rhinoceros
(b) Pollution Royal Bengal Tiger
(c) Global warming and climatic change Polar Bear 
(d) Hunting and Poaching Vulture 

1.15 Which of the following phenomena occurs when chlorinated insecticides enter a food chain- 

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

Group ‘B’

2. Answer 21 questions out of the 26 questions given below, as instructed. 1 x 21=21 

Fill in the blanks with proper words in the following sentences (any five)

2.1 Nastic movement is influenced and controlled by the __________of an external stimulus.

2.2 _______________ cell division maintains the number of chromosomes constant in a species.

2.3 The wrinkled shape of seed is a___________trait

2.4 Because of its_____________ shape, the RBC of camel can withstand a considerable loss of water.

2.5 A disease related to air pollution is _________________

2.6 Nilgiri and ______________are both Biosphere Reserves. 

Decide whether the following statements are True or False (any five):

2.7 Auxin hormone inhibits the growth of apical bud and increases the growth of axillary bud.

2.8 Cell division becomes uncontrolled if the function of checkpoints becomes hampered.

2.9 Only one type of gamete is produced from a pea plant having genotype YyRR.

2.10 Both intraspecific and interspecific struggles might be observed among the different types of tigers in a forest.

2.11 Nitrous oxide is a greenhouse gas.

2.12 Triceps is a flexor muscle.

Match the words in column-A with the most appropriate words in column-B and re-write the correct pair mentioning the serial no. of both columns (any five) 

Column A	Column B
2.13 Meninges	(a) Decrease in the number digits in the legs
2.14 Sexual reproduction	(b) Submergence of islands
2.15 Roller tongue	(c) Centromere
2.16 Evolution of horse	(d) Telomere
2.17 Environmental problem of Sundarban	(e) Protects brain and spinal cord from mechanical injury
2.18 Attaches chromosome with spindle fibre	(f) Controlled by autosome (g) Occurs through production of gametes and their union

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

 2.19 Choose the odd word and write it: Testosterone, Insulin, Progesterone, Oestrogen 

2.20 What is the relation between lens and accommodation of eye? 

2.21 On the basis of the relationship in the first related pair of words, write a suitable word in the gap of the second pair.

Mitosis: Equational division:: _______:Reduction division 

2.22 In spite of being pure in respect of one trait what else could an organism be in respect of another trait?

2.23 Write one feature of the gene responsible for colour blindness. 

2.24 Which theory can be reached at from the comparative study of the embryos of different vertebrate animals?

2.25 Among the following four terms, one includes the other three. Find it out and write it :

Shrinking of agricultural land, shortage of fresh water, problems of ever increasing population, deforestation

2.26 Write one feature of biodiversity hotspot.

Group ‘C’

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

3.1 The two reflex actions, namely sneezing and coughing help in avoiding danger-justify the statement. 

3.2 How does the Gibberellin hormone cause the seeds to germinate and the plants to grow in height?

3.3 Write one influence each of Thyroxine hormone on the heart and the RBC.

3.4 Explain the following two terms:

• Ganglia
• Synapse

3.5 Write two features of Amitotic cell division. 

3.6 Mention any two phenomena during G, phase of Interphase. 

3.7 Explain the process of segmentation with the help of a proper example of plants.

3.8 What is the importance of genetic counselling in arranging a marriage?

3.9 Write two reasons behind selection of pea plant by Mendel for his expériments on heredity.

3.10 Judge with reason the probability of what percentage of the children born to a colour blind father and a completely normal mother would be colour blind.

3.11 An inherent trait of organisms is the prodigality of reproduction; as a result the number of organisms increase in a geometric proportion -justify the validity of the statement with two proper examples. 

3.12 How do worker bees communicate the information to the other worker bees of the hive when they spot any source of food?

3.13 What do you mean by natural selection?

3.14 One of the problems associated with ever increasing population is destruction of wetland-Mention any two consequences of this. 

3.15 Invasion of exotic species causes reduction in biodiversity- establish the validity of this statement with two examples with reference to India.

3.16 Write the names of one endangered plant and one animal species of the Eastern Himalayas biodiversity hotspot. 

3.17 Write one role of Joint Forest Management (JFM) and People’s Biodiversity Register (PBR) each for the conservation of biodiversity. 

Group ‘D’

(Long answer type questions).

4. Write all 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 marks allotted for each questions is 5 (the division of marks is either 3+2, 2+3 or 5) 5×6=30

4.1 Draw a scientific diagram of the vertical section of a human eyeball and label the following parts: 

(a) Choroid
(b) Lens
(c) Cornea 
(d) Vitreous humor

OR

Draw a scientific diagram of the anaphase stage of mitotic cell division in ar animal cell and label the following parts-

(a) Centromere
(b) Daughter chromosome 
(c) Polar region 
(d) Spindle fibre 

(FOR SIGHTLESS CANDIDATES ONLY)

4.1 (A) Write one function of each of the following five parts of the human eyeball: 

(a) Cornea 
(b) Lens 
(c) Choroid 
(d) Vitreous humor
(e) Retina

OR, Mention three changes occurring during the Anaphase stage of mitosis in an animal cell. Write the names of any two structural parts of eukaryotic chromosome.

4.2 Explain the following three significances of cell division- 

• Reproduction
• Growth
• Repair 

Tabulate the site of occurrences of meiotic cell division in living world.

OR, Explain the process of micropropagation. Distinguish between asexual and sexual reproduction on the basis of the following three features-

No. of Parental organisms

• Cell Division 
• Origin of.variation

4.3 With the help of a checkerboard show the phenotypic ratio of offsprings produced in F, generation as a result of a cross between a pure black coloured and rough haired guinea-pig and a pure white and smooth haired guinea-pig. “Father plays the main role in the determination of sex of the offspring”-justify the statement with the help of a checkerboard.

OR, Write three reasons behind Mendel’s success. Establish relationship between phenotype and genotype with the help of proper example.

Explain the theory of Darwin with regards to lengthening of neck of giraffe. What do you mean by ‘Hot Dilute Soup’?

OR, Construct the sequence of major events of organic evolution with the help of a schematic diagram. Give two examples of problem solving ability of chimpanzee.

4.5 Write one symptom each of two diseases which might be caused if suspended particulate matter enters into the respiratory tract through inspiration. Construct the sequence of events when agricultural runoff is drained into water bodies.

Poaching is one of the main reasons behind depletion of biodiversity- Prepare a list of any three such endangered wild animals resulting from it. Show the various methods of conservation of biodiversity with the help of a chart.

4.6 Three environmental problems of the Sundarbans are-

• imbalance in the numbers of prey and predators
• destruction of mangrove plants due to urbanisation
• rising sea level

Analyze the probable effects of the three problems. Mention the location and the name of one endangered species of a biodiversity hotspot distributed in and outside the geographical area of India.

OR

Describe the nitrogen cycle with the help of a word diagram. Analyse any two problems which may arise if nitrogen cycle is disturbed.

Group ‘E’ (FOR EXTERNAL CANDIDATES ONLY)

5. Answer any four questions:  1×4=4

5.1 Write one feature of epithelial tissue. 

5.2 What is the function of ribosome? 

5.3 Write one function of parenchyma tissue. 

5.4 Write one advantage of self-pollination.

5.5 Give an example of a proteolytic enzyme. 

6. Answer any three questions: 2×3=6

6.1 Write two differences between axon and dendron.

6.2 Write the names of two nitrogenous excretory products of plants.

6.3 Write one function each of mitochondria and centrosome. 

6.4 Write the name of two sanctuaries of West Bengal.