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Biology October 2017 HSC Board Question Paper Maharashtra Board

BIOLOGY JULY 2017 HSC

Board Paper With Solutions

HSC Biology

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Biology March 2017 HSC Board Question Paper Maharashtra Board

BIOLOGY MARCH 2017 HSC

HSC Biology Board Paper With Solutions

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Maharashtra Board Class 12 Biology Question Paper Solutions March 2022

BOARD QUESTION PAPER : MARCH 2022
BIOLOGY

Time: 3 Hrs. | Max. Marks: 70

SECTION A

Q.1. Select and write the correct answer for the following multiple choice type of questions:

i. How many meiotic and mitotic divisions occur during the development of male gametophyte from the microspore mother cell?

  • (A) One meiotic and two mitotic
  • (B) Two meiotic only
  • (C) Two mitotic only
  • (D) One mitotic and one meiotic

Answer: (A) One meiotic and two mitotic

ii. During replication of DNA, the separated strands are prevented from recoiling by using _______.

  • (A) single strand binding protein
  • (B) reverse transcriptase
  • (C) endonuclease
  • (D) polymerase

Answer: (A) single strand binding protein

iii. Which event is represented by the above diagram, related to chromosomal aberrations?

  • (A) Deletion
  • (B) Duplication
  • (C) Inversion
  • (D) Translation

Answer: (C) Inversion

iv. _______ hormone responsible for efflux of k+ ions from guard cells and act as antitranspirant.

  • (A) Gibberellins
  • (B) Cytokinin
  • (C) Ethylene
  • (D) Abscissic acid

Answer: (D) Abscissic acid

v. Test tube baby technique is called _______.

  • (A) In-vitro fertilization
  • (B) In-situ fertilization
  • (C) In-vivo fertilization
  • (D) Artificial insemination

Answer: (A) In-vitro fertilization

vi. While playing cricket Raju faces problem of severe pain and heaviness in the chest. Pain spreads from neck, lower jaw, left arm and to left shoulder. From above symptoms identify disease

  • (A) Malaria
  • (B) Angina pectoris
  • (C) Kidney failure
  • (D) Typhoid

Answer: (B) Angina pectoris

vii. _______ layer is in close contact of CNS in human being.

  • (A) Cranium
  • (B) Dura matter
  • (C) Arachnoid matter
  • (D) Pia matter

Answer: (D) Pia matter

viii. Cellular factors in innate immunity is provided by ______.

  • (A) phagocytes
  • (B) antibody
  • (C) T - lymphocyte
  • (D) B - lymphocyte

Answer: (A) phagocytes

ix. Pick out the appropriate association representing brood parasitism.

  • (A) Hermit crab and sea anemone
  • (B) Asian koel and common Indian crow
  • (C) Algae and fungi
  • (D) Buffalo and cattle egret

Answer: (B) Asian koel and common Indian crow

x. Annealing step of PCR, operates at _______ °C.

  • (A) 90 – 98
  • (B) 40 – 60
  • (C) 70 – 75
  • (D) 100 – 120

Answer: (B) 40 – 60

HSC Biology

Q.2. Answer the following questions:

i. Name the part of gynoecium that determines the compatibility of pollen grains.

Answer: Stigma (pistil).

ii. Which is the primary precursor of IAA in plants?

Answer: Tryptophan.

iii. Name the cell which is responsible for nitrogen fixation in cyanobacteria.

Answer: Heterocyst.

iv. How many Biodiversity hotspots have been identified around the world?

Answer: 34 Biodiversity hotspots.

v. Name the plant disease caused by Agrobacterium tumefaciens.

Answer: Crown gall disease.

vi. Identify the trophoblast cells which are in contact with embryonal knob during blastulation.

Answer: Cells of Rauber.

Population Growth Curve Diagram

vii. From the given diagram, identify the type of population growth curve:

Answer: J-shaped growth curve (Exponential growth).

viii. What do you mean by Pioneer species?

Answer: The first species to colonize a bare area (e.g., bare rock) to initiate ecological succession is called a pioneer species. Examples include lichens.

SECTION  B

Attempt any EIGHT of the following questions:

Q.3. Identify A, B, C, D, in the given diagram of human reproductive system:

Human Reproductive System Diagram

Answer:
A: Testis
B: Vas deferens
C: Ureter
D: Seminal vesicle

Q.4. Identify chromosomal disorder caused due to non-disjunction of 21st number of chromosome and enlist its symptoms.

Answer:

Disorder: Down's Syndrome (Trisomy 21).

Symptoms:
  • Mild to moderate mental retardation.
  • Flat face with rounded head.
  • Protruding tongue and open mouth.
  • Short stature and stubby fingers.
  • Simian crease on palm.
  • Epicanthal fold of skin over the inner corner of the eye.

Q.5. Write the aims of human genome project.

Answer:
  • To identify all the approximately 20,000-25,000 genes in human DNA.
  • To determine the sequences of the 3 billion chemical base pairs that make up human DNA.
  • To store this information in databases.
  • To improve tools for data analysis.
  • To transfer related technologies to other sectors, such as industries.
  • To address the Ethical, Legal, and Social Issues (ELSI) that may arise from the project.

Q.6. Match the parts of ovule given in column I with parts of seed given in column II:

Column IColumn II
(a) egg(1) testa
(b) nucellus(2) tegmen
(c) outer integument(3) perisperm
(d) inner integument(4) embryo
Answer:
  • (a) - (4) embryo
  • (b) - (3) perisperm
  • (c) - (1) testa
  • (d) - (2) tegmen

Q.7. Enlist the characteristics of Neanderthal Man.

Answer:
  • They had heavy brow ridges and a receding forehead.
  • Brain size was approximately 1400 cc (cranial capacity).
  • They were short in stature but had a strong body build.
  • They used animal hides (skins) for clothing to protect themselves from cold.
  • They buried their dead and possibly had religious beliefs.
  • They used fire and made tools.

Q.8. Define the following:

(a) Gravitational water (b) Hygroscopic water (c) Combined water (d) Capillary water

Answer:
  • (a) Gravitational water: The free water that moves downwards through the soil due to the force of gravity and settles at the water table is called gravitational water.
  • (b) Hygroscopic water: Water held tightly around the soil particles by cohesive and adhesive forces, which cannot be easily removed by plants, is called hygroscopic water.
  • (c) Combined water: Water present in the form of hydrated oxides of silicon, aluminum, etc., chemically bound to soil particles, is called combined water.
  • (d) Capillary water: Water held in the micropores of the soil against the force of gravity is called capillary water. This is the only form of water available to plant roots.

Q.9. Give different properties of water.

Answer:
  • Water is a universal solvent.
  • It has high specific heat capacity.
  • It has high heat of vaporization and heat of fusion.
  • Water molecules show cohesive and adhesive properties.
  • It is liquid at room temperature and has a neutral pH.
  • Water shows anomalous expansion (maximum density at 4°C).

Q.10. A person met with a small accident and bleeds, but very soon stops bleeding. Explain the physiological process responsible for this.

Answer: The physiological process is Blood Coagulation (Clotting).
  1. At the site of injury, platelets rupture and release thromboplastin.
  2. Thromboplastin initiates the formation of the enzyme prothrombinase (thrombokinase).
  3. Prothrombinase, in the presence of Ca++ ions, converts inactive Prothrombin into active Thrombin.
  4. Thrombin converts soluble Fibrinogen protein into insoluble Fibrin threads.
  5. Fibrin threads form a mesh that traps blood cells, forming a clot that stops bleeding.

Q.11. Match the antibiotics in column I with their microbial sources in column II:

Column IColumn II
(a) Chloromycetin(1) Streptomyces griseus
(b) Erythromycin(2) Streptomyces aurifaciens
(c) Streptomycin(3) Streptomyces Venezuelae
(d) Terramycin(4) Streptomyces erythreus
Answer:
  • (a) Chloromycetin - (3) Streptomyces Venezuelae
  • (b) Erythromycin - (4) Streptomyces erythreus
  • (c) Streptomycin - (1) Streptomyces griseus
  • (d) Terramycin - (2) Streptomyces aurifaciens (Note: Commonly S. rimosus, but mapped to S. aurifaciens in this context)

Q.12. Abscissic acid is the common name given to two identical substances isolated separately. Name them. Give the chemical features of abscissic acid.

Answer:

Names: Inhibitor-B and Abscission II.

Chemical features:

  • It is a 15-carbon sesquiterpenoid.
  • It acts as a plant growth inhibitor.
  • It is synthesized from carotenoids (violaxanthin) in chloroplasts.

Q.13. What are the effects of biotechnology with relation to human health?

Answer: Biotechnology has revolutionized healthcare in the following ways:
  • Production of Vaccines: Development of safe and effective vaccines (e.g., Hepatitis B vaccine).
  • Therapeutic Proteins: Mass production of proteins like Insulin for diabetes and Somatostatin.
  • Gene Therapy: Treating genetic disorders by replacing defective genes (e.g., treatment for SCID).
  • Diagnostics: Advanced diagnostic techniques like PCR and ELISA for early disease detection.

Q.14. Give the adaptations shown by desert animals.

Answer:
  • Nocturnal habit: Animals come out only at night to avoid daytime heat.
  • Water conservation: Excretion of concentrated urine (e.g., Kangaroo rat) and dry feces to minimize water loss.
  • Metabolic water: Some animals (like camels and kangaroo rats) use water produced by the oxidation of fats.
  • Morphological features: Thick skin to prevent water loss, long legs to keep body away from hot ground (camel), and padded feet for walking on sand.

SECTION  C

Attempt any EIGHT of the following questions:

Q.15. Explain natural selection with example of industrial melanism.

Answer:

Natural Selection: The process where nature selects organisms with favorable variations to survive and reproduce.

Example: Industrial Melanism in Peppered Moth (Biston betularia):

  • Before Industrialization (Great Britain, pre-1845): Trees were covered with white lichens. White-winged moths blended in (camouflage) and escaped predators, while dark-winged (melanic) moths were easily spotted and eaten. White moths outnumbered dark ones.
  • During/After Industrialization: Soot and smoke killed lichens and turned tree trunks black. Now, dark-winged moths were camouflaged against the dark bark, while white moths were conspicuous and eaten by birds.
  • Result: Nature selected the dark variety for survival in the polluted environment. The population of dark moths increased, demonstrating directional natural selection.

Q.16. Describe physiological effect and applications of gaseous hormone in plants.

Answer:

The gaseous hormone is Ethylene.

Physiological Effects:

  • Promotes ripening of fruits (climacteric fruits).
  • Stimulates abscission (shedding) of leaves, flowers, and fruits.
  • Breaks seed and bud dormancy.
  • Promotes senescence (aging).
  • Inhibits longitudinal growth and stimulates transverse growth (triple response).

Applications:

  • Used as Ethephon to artificially ripen fruits like bananas and mangoes.
  • Used to induce flowering in mango and pineapple.
  • Used for thinning of cotton, cherry, and walnut.

Q.17. What is ecological succession? Name various seral stages from pioneer species to climax community with suitable example in hydrarch succession.

Answer:

Ecological Succession: The gradual and predictable change in the species composition of a given area is called ecological succession.

Stages in Hydrarch Succession (Succession in Water):

  1. Pioneer Stage (Phytoplankton): Minute microscopic plants like algae.
  2. Submerged Plant Stage: Plants rooted in mud (e.g., Hydrilla, Vallisneria).
  3. Submerged Free-floating Plant Stage: Plants like Pistia, Eichhornia.
  4. Reed-swamp Stage: Amphibious plants (e.g., Typha, Phragmites).
  5. Marsh-meadow Stage: Mud-loving plants (e.g., Sedges, Grasses).
  6. Scrub Stage: Woody shrubs (e.g., Salix, Cornus).
  7. Climax Community (Forest): Stable forest trees (e.g., Oak, Teak).

Q.18. With the help of a neat, labelled diagram describe the structure of root hair.

Answer: Root Hair Diagram
  • Origin: A root hair is a unicellular, tubular extension of an epiblema (epidermal) cell of the root.
  • Size: It is approx 1 to 10 mm long.
  • Cell Wall: It has a double-layered cell wall. The outer layer is composed of pectin, and the inner layer is composed of cellulose.
  • Internal Structure: Inside the cell wall is the cell membrane. The cytoplasm contains a large central vacuole, pushing the nucleus and cytoplasm to the periphery (primordial utricle).
  • Function: It increases the surface area for absorption of water and minerals.

Q.19. Complete the following flow diagram of double circulation:

Flow Diagram Placeholder
Answer:

Missing Labels filled:

  • Box below Right Atrium: Right Ventricle
  • Box above Left Ventricle: Left Atrium

Flow:

  • Pulmonary Circulation: Right Ventricle → Lungs → Left Atrium
  • Systemic Circulation: Left Ventricle → Body Organs → Right Atrium

Q.20. Distinguish between hyperthyroidism and hypothyroidism.

Answer:
Feature Hyperthyroidism Hypothyroidism
Cause Caused by oversecretion of thyroid hormones. Caused by undersecretion of thyroid hormones.
Metabolic Rate (BMR) Increases BMR significantly. Decreases BMR.
Weight Leads to weight loss despite increased appetite. Leads to weight gain.
Symptoms Nervousness, protruding eyeballs (Exophthalmos), high heart rate, sweating. Lethargy, dry skin, swelling (Myxedema), mental retardation in children (Cretinism).
Disorders Graves' disease (Exophthalmic goiter). Cretinism (in children), Myxedema (in adults).

Q.21. Give the applications of DNA fingerprinting.

Answer:
  • Forensic Science: Used to identify criminals in rape and murder cases by analyzing biological evidence (blood, hair, semen) found at crime scenes.
  • Paternity Disputes: Used to determine the biological parents of a child in case of disputes.
  • Identification: Used to identify deceased bodies that are unrecognizable (e.g., after accidents or disasters).
  • Evolutionary Biology: Used to study phylogenetic relationships and evolutionary history of organisms.
  • Pedigree Analysis: Used in verification of pedigree in animals and humans.

Q.22. Write a note on In-situ and Ex-situ conservation.

Answer:

In-situ Conservation (On-site):

  • Conservation of species within their natural habitats.
  • The entire ecosystem is protected.
  • Examples: National Parks, Wildlife Sanctuaries, Biosphere Reserves, Sacred Groves.

Ex-situ Conservation (Off-site):

  • Conservation of endangered species outside their natural habitats in specially protected environments.
  • Human care is provided.
  • Examples: Zoological parks (Zoos), Botanical gardens, Seed banks, Cryopreservation (storing gametes at -196°C), Gene banks.

Q.23. Explain the properties of nerve fibres.

Answer:
  • Excitability: Ability to perceive a stimulus and enter a state of activity (action potential).
  • Conductivity: Ability to transmit the excitation (impulse) along the length of the nerve fiber.
  • Stimulus Threshold: A minimum strength of stimulus (threshold stimulus) is required to generate an impulse.
  • All or None Law: The nerve fiber either responds completely to a stimulus or not at all, provided the stimulus is at threshold level.
  • Refractory Period: A short period after excitation during which the nerve cannot respond to a second stimulus.
  • Summation: Multiple weak stimuli (sub-threshold) applied in quick succession can generate an impulse.

Q.24. Give the causative agent, mode of transmission and symptoms of typhoid.

Answer:
  • Causative Agent: Salmonella typhi (bacteria).
  • Mode of Transmission: Fecal-oral route; consuming food or water contaminated with feces of an infected person. Houseflies can also act as mechanical vectors.
  • Symptoms:
    • Sustained high fever (103°F – 104°F).
    • Weakness and fatigue.
    • Stomach pain and constipation.
    • Headache.
    • Loss of appetite.
    • Intestinal perforation in severe cases.

Q.25. Match the following products with their microbial sources:

ProductsMicrobial Sources
(a) Vitamin B2(1) Rhizopus arrhizus
(b) Fumaric acid(2) Candida lipolytica
(c) Vitamin B12(3) Trichoderma Konigii
(d) Lipase(4) Neurospora gossypii
(e) Cellulase(5) Psuedomonas denitrificans
(f) Citric Acid(6) Aspergillus niger
Answer:
  • (a) Vitamin B2 - (4) Neurospora gossypii (or Ashbya gossypii)
  • (b) Fumaric acid - (1) Rhizopus arrhizus
  • (c) Vitamin B12 - (5) Psuedomonas denitrificans
  • (d) Lipase - (2) Candida lipolytica
  • (e) Cellulase - (3) Trichoderma Konigii
  • (f) Citric Acid - (6) Aspergillus niger

Q.26. Explain any three examples of biopiracy.

Answer:

Biopiracy is the unauthorized use of bio-resources and traditional knowledge by organizations without proper authorization from the countries or people concerned. Examples:

  1. Turmeric: In 1995, the US Patent Office granted a patent to the University of Mississippi Medical Center for the use of turmeric in wound healing. India challenged this, citing ancient Ayurvedic texts proving prior knowledge, and the patent was revoked.
  2. Neem: The EPO granted a patent to W.R. Grace & Co. for the fungicidal use of neem oil. India challenged this based on traditional Indian knowledge of neem's properties, and the patent was revoked.
  3. Basmati Rice: In 1997, RiceTec Inc. (USA) obtained a patent for "Basmati rice lines and grains," claiming they invented a new variety. This was actually derived from Indian Basmati crossed with semi-dwarf varieties. India challenged this to protect its export market.

SECTION  D

Attempt any THREE of the following questions:

Q.27. With the help of neat and labelled diagrams, distinguish between artery and vein.

Answer: Artery and Vein Diagram
Artery Vein
Carries blood away from the heart to body parts. Carries blood towards the heart from body parts.
Usually carries oxygenated blood (except pulmonary artery). Usually carries deoxygenated blood (except pulmonary vein).
Thick-walled and elastic. Tunica media is thick. Thin-walled and less elastic. Tunica media is thin.
Lumen is narrow. Lumen is wide.
Valves are absent. Valves are present to prevent backflow.
Blood flows under high pressure. Blood flows under low pressure.
Deep-seated in the body. Usually superficial.

Q.28. State the names of hormone and glands secreting them:

Answer:
  • (a) Growth of thyroid gland:
    Hormone: TSH (Thyroid Stimulating Hormone)
    Gland: Anterior Pituitary (Adenohypophysis).
  • (b) Controls tubular absorption of water in kidney:
    Hormone: ADH (Antidiuretic Hormone) / Vasopressin
    Gland: Posterior Pituitary (Neurohypophysis) [Synthesized by Hypothalamus].
  • (c) Stimulates liver and muscles for glycogenesis:
    Hormone: Insulin
    Gland: Pancreas (Beta cells of Islets of Langerhans).
  • (d) Development of immune system and maturation of T-lymphocyte:
    Hormone: Thymosin
    Gland: Thymus Gland.

Q.29. Describe outbreeding devices which encourages cross pollination.

Answer:

Outbreeding devices are mechanisms that prevent self-pollination and promote cross-pollination to increase genetic diversity:

  1. Unisexuality (Dioecism): The plant bears either only male or only female flowers (e.g., Papaya, Mulberry). Self-pollination is impossible.
  2. Dichogamy: Anthers and stigmas mature at different times in a bisexual flower.
    • Protandry: Anthers mature first (e.g., Sunflower).
    • Protogyny: Stigma matures first (e.g., Gloriosa).
  3. Prepotency: Pollen grains of another flower germinate more rapidly over the stigma than the pollen grains from the same flower (e.g., Apple).
  4. Heterostyly: Flowers have different lengths of styles and stamens, preventing pollen from reaching the stigma of the same flower (e.g., Primrose).
  5. Herkogamy: Physical barriers prevent self-pollination (e.g., in Calotropis, the pollinium is located such that it cannot reach the stigma).
  6. Self-sterility (Self-incompatibility): The pollen grains of a flower cannot germinate on the stigma of the same flower due to genetic mechanisms (e.g., Tobacco).

Q.30. Explain the law of dominance and compare how it differs from incomplete dominance and co-dominance.

Answer:

Law of Dominance (Mendel's First Law):

  • When two homozygous individuals with one or more sets of contrasting characters are crossed, the alleles (characters) that appear in the F1 hybrid are dominant, and those that do not appear are recessive.
  • Example: Tall (TT) x Dwarf (tt) → All Tall (Tt). The Tall character dominates.

Comparison:

Feature Law of Dominance Incomplete Dominance Co-dominance
Effect of Alleles One allele completely masks the other. Neither allele is completely dominant. Both alleles are equally dominant.
F1 Phenotype Resembles only the dominant parent. Intermediate blend of both parents. Both parental traits are expressed side-by-side.
Example Tall x Dwarf = Tall Pea Plant. Red x White = Pink Flower (Mirabilis jalapa). Red x White = Roan Cattle (Patches of Red and White).

Q.31. Describe hormonal control in various phases of menstrual cycle.

Answer:
  1. Menstrual Phase (Days 1-5):
    • Progesterone and Estrogen levels are low.
    • The withdrawal of these hormones causes the breakdown of the endometrium, leading to menstruation.
  2. Follicular / Proliferative Phase (Days 5-13):
    • FSH (Follicle Stimulating Hormone) from the pituitary stimulates the growth of ovarian follicles.
    • Growing follicles secrete Estrogen.
    • Estrogen stimulates the repair and proliferation (thickening) of the endometrium.
  3. Ovulatory Phase (Day 14):
    • Estrogen levels peak, triggering a surge in LH (Luteinizing Hormone).
    • The LH surge causes the rupture of the Graafian follicle and release of the ovum (Ovulation).
  4. Luteal / Secretory Phase (Days 15-28):
    • LH transforms the empty follicle into the Corpus Luteum.
    • Corpus Luteum secretes large amounts of Progesterone and some Estrogen.
    • Progesterone maintains the endometrium for potential implantation (makes it glandular and vascular).
    • High Progesterone inhibits FSH and LH (Negative Feedback) to prevent new follicle development.
    • If fertilization does not occur, Corpus Luteum degenerates, Progesterone drops, and the cycle restarts.
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HSC Chemistry March 2017 Question Paper Maharashtra Board

HSC Chemistry Archive

CHEMISTRY MARCH 2017 HSC

HSC Chemistry Question Paper March 2017 Page 1
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Important Physics Practice Papers for Board Exam 2026 (Set of 4)

Important Physics 4 practice papers for Board exam 2026 Must study paper.

HSC Physics Board Papers with Solution

Question Paper Page No. 1 Question Paper Page No. 2 Question Paper Page No. 3 Question Paper Page No. 4 HSC Physics Model Question Paper
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