Madhyamik 2025 Life Science Question Paper | Madhyamik 2025 Life Science Question Paper
Section — ‘A’
(All questions must be answered)
1. Complete the sentence by choosing the correct answer to each question and writing its serial number. 1 x 15 = 15
1.1 Select the correct pair —
a) Sclera — absorbs excess light inside the eyeball
b) Choroid — gives the eyeball a specific shape
c) Lens — refracts light and performs accommodation
d) Retina — holds the lens in place with the help of suspensory ligaments
1.2 Identify which of the following statements regarding adrenaline is not correct:
a) Increases heart rate
b) Helps in sperm production during puberty
c) Increases cardiac output
d) Increases systolic blood pressure
1.3 Select which of the following is a characteristic of tropic movement —
a) The involuntary movement of certain plant organs controlled by the direction of the stimulus
b) It is a type of vasodilation
c) The involuntary movement of plant organs controlled by the intensity of the stimulus
d) Does not occur under the influence of auxin
1.4 Match the words given in column ‘A’ with the words given in column ‘B’ and select which of the following answers is correct:
Pillar ‘A’ Pillar B
A. CSF (i) protects the central nervous system from mechanical injury
B. Meninges (ii) helps in the formation of myelin sheath
C. Neuroglia (iii) acts as shock absorbers
1.5 Determine the correct order of the following —
a) Receptor → Agent → Sensory → Nerve → Efferent Nerve → Nerve Center
b) Receptor → Nerve Center → Efferent Nerve → Sensory Nerve → Agent
c) Receptor → Sensory Nerve → Nerve Center → Efferent Nerve → Agent
d) Receptor → Efferent Nerve → Nerve Center
1.6 Select the correct pair —
a) Telophase – movement of daughter chromosomes towards the poles
b) Telophase – disappearance of the nuclear envelope and nucleolus
c) Telophase – formation of the cytoplasm
d) Telophase – reappearance of the nuclear envelope and nucleolus
1.7 The two ends of a chromosome are called —
a) Centromere
b) Telomere
c) Nucleolar organizer
d) Satellite
1.8 Identify which of the following statements regarding cross-pollination is not correct:
a) Carriers are needed
b) New traits arise in the lineage
c) Purity of the species is maintained
d) Seed germination rate is high
1.9 Consider the following differences between asexual and sexual reproduction and choose which ones are correct —
Asexual reproduction Sexual reproduction
I. Two reproductive organisms of the same species of opposite sex are required. Asexual organisms can be produced from a single reproductive organism.
II. This type of reproduction is accomplished through cell division or cell division. This type of reproduction is accomplished through gamete production and union.
III. Depends on amitosis, mitosis and meiosis. Depends on meiosis.
IV. Variation is seen in the reproductive organisms. The reproductive organisms look exactly like the reproductive organisms.
1.10 In the case of humans, select the correct pair —
a) Normal chromosome arrangement of the egg — 22A + XX
b) Normal chromosome arrangement of the egg — 22A + Y
c) Normal chromosome arrangement of the egg — 22A + X
d) Normal chromosome arrangement of the egg — 22A + XY
1.11 Determine which of the following genotypes is homozygous for both loci —
a) BbRr b) BBRr c) BbRR d) bbrr
1.12 Identify the genotype of a guinea pig with white and uneven fur —
a) bbRR, bbrr b) BBRR, bbrr c) bbRR, bbRr d) BbRr, BbRR
1.13 Determine which two of the following were selected by Mendel as dominant traits:
a) Stem length — long, seed shape — round
b) Flower position — apex, flower color — white
c) Cotyledon color — green, seed shape — wrinkled
d) Stem length — short, seed shape — wrinkled
1.14 Determine the nature of the pea plants produced from the seeds obtained by pollination of a hybrid long (Tt) and a pure short (tt) pea plant.
a) 100% long b) 50% long, 50% short c) 100% short d) 75% long, 25% short
1.15 Decide which of the following diseases can be prevented by undergoing genetic counseling before marriage:
a) Goiter b) Malaria c) Thalassemia d) Tuberculosis
Category — ‘B’
2. Write the answers to 21 of the 26 questions below as instructed. 1 x 21 = 21
Fill in the blanks in the sentences below with the appropriate word (any five): 1 x 5 = 5
2.1 ——— Hormones are found in very large quantities in the mature seeds of plants.
2.2 Reflexes are fast, spontaneous, and ———.
2.3 ——— The cell division does not produce a filament.
2.4 ——— An insect-pollinated flower.
2.5 The gene that has the ability to roll the roller tongue is ———.
2.6 Since the gene responsible for hemophilia is recessive, the symptoms of this disease are only manifested in the ——— condition.
Determine whether the following sentences are true or false (any five): 1 x 5 = 5
2.7 The focal length of the lens increases when viewing distant objects.
2.8 Each nucleoside contains a nitrogenous base and phosphoric acid.
2.9 The wife has no role in determining the sex of a person.
2.10 If a pea plant has the trait TT or tt, then the pea plant is heterozygous with respect to this allele.
2.11 Since pea flowers are unisexual, pea plants can be self-pollinated and, if necessary, cross-pollinated.
2.12 During the cell division stage, the daughter cells undergo various changes and transformations to form tissues, organs, and fibers.
Match the word given in column A with the most appropriate word given in column B, giving the serial number of both columns.
Rewrite the correct pair with the reference (any five): 1 x 5 = 5
A pillar B pillar
2.13 Polyuria a) Independent assortment principle
2.14 Swan cell b) Fragile osteogenesis
2.15 Meiosis c) Located between the neurolemma and myelin sheath of the axon
2.16 Old age d) Low secretion of ADH
2.17 Genetic diseases e) Germ cell and gamete cell
f) Color blindness
2.18 Mendel’s second law g) Law of segregation
Answer in one word or one sentence (any six) 1 x 6 = 6
2.19 Write the word “unlike” more often:
Olfactory nerve, vagus nerve, optic nerve, auditory nerve
2.20 What are the consequences of hormones after their work in the animal body is completed?
2.21 Given below is a related pair of words. Understand the relationship between the first pair and fill in the blanks of the second pair with the appropriate word:
Urine : Adenine : : Pyrimidine : ———
2.22 What happens if the checkpoint function is disrupted in the cell cycle?
2.23 What is hybridization?
2.24 What are the salient features?
2.25 Three out of the four topics below belong to one topic. Find out that topic and write —
Increased basal metabolic rate, thyroxine, red blood cell degeneration, exophthalmic goiter.
2.26 In which stage of interphase are proteins required for the formation of the mitotic spindle synthesized?
Category — ‘C’
3. Write the answer to any 12 of the 17 questions below in two or three sentences: 2 x 12 = 24
3.1 Make a list of the hormones that control the following functions:
• The cartilage at the ends of long bones increases the length of the bone by causing mineralization of the metal.
• The ruptured ovary turns into a temporary endocrine gland called the ovary and provides the necessary stimulation for the secretion of the hormone progesterone from that gland.
• It inhibits the production of glucose from proteins and lipids in the liver.
• Causes uterine muscle contractions during labor.
3.2 Explain the causes of myopia and hyperopia.
3.3 Explain what happens as a result of the contraction of the following muscles:
• Flexor muscles
• Extensor muscles
• Abductor muscles
• Rotator muscles
3.4 Make a list of the functions of plant growth that are controlled by auxin.
3.5 Identify the differences between mitosis in plant cells and mitosis in animal cells based on the following characteristics:
• Cellular structure
• Cytokinesis process
3.6 Explain how natural organs propagate with the help of asexual budding.
3.7 Write down the changes that occur in chromosomes during the anaphase stage of nuclear division.
3.8 Describe how the process of burning Esther’s ashes is accomplished.
3.9 Make a list of the changes that occur during puberty in human development.
3.10 Explain the following two meanings of meiosis:
• Keeping the chromosome number of a species constant
• Origin of variation within organisms
3.11 State Mendel’s second law of heredity.
3.12 “In case of incomplete dominance, phenotypic and genotypic ratios are identical” — Prove the correctness of the statement.
3.13 Write two reasons for Mendel’s success in genetic experiments.
3.14 “A driving force for movement is the spread of life” — Judge the validity of the statement with the help of suitable examples.
3.15 Show the chemical composition of chromosomes with the help of a table.
3.16 Compare the following properties between DNA and RNA:
• Nature of sugars
• Nature of pyrimidine bases
3.17 “Some phenotypes can have more than one genotype and some other phenotypes can have only one genotype” —Prove the correctness of the statement from the results obtained from the cross-breeding experiment in pea plants.
Category — ‘D’
4. Answer the following 6 questions or their alternative questions. Visually impaired candidates will have to answer question 4.1 (A) instead of question 4.1. Each question carries 5 marks (divide the question marks by 3+2, 2+3, or 5): 5 x 6 = 30
4.1 Draw a scientific diagram of a neuron and identify the following parts: 3+2=5
a) Axon
b) Node of Ranvier
c) Dendron
d) Swanson’s sheath
Or
Draw a scientific diagram of the anatomical structure of a eukaryotic chromosome and identify the following parts: 3+2=5
a) Chromatid
b) Telomere
c) Centromere
d) Nucleolar organizer
(For visually impaired candidates only)
4.1 (A) Write one function of each of the following parts of a neuron: 1×5=5
a) Dendron
b) Axon
c) Myelin
d) Swanson’s sheath
e) Node of Ranvier
Or
Write the function of each of the following structural parts of a eukaryotic chromosome: 1 x 5=5
a) Centromere
b) Nucleolar organizer
c) Chromatid
d) Telomere
e) Kinetochore
4.2 Compare the functions of the following three pairs of hormones that have opposing functions in the human body.
• Insulin and glucagon
• Estrogen and progesterone
• FSH and LH
Explain the relationship between the hindbrain and the function of controlling respiration. 3+2=5
Or
The following physical functions of a person injured in an accident are impaired. Name the parts of the brain associated with these functions.
• Speech
• Hunger, thirst and sleep
• Posture and body balance
• Tongue movement and swallowing
Explain the feedback control mechanism of hormonal action with the help of a suitable example. 3+2=5
4.3 Make a list of the roles of synthetic plant hormones in agriculture and horticulture. What are the effects of insulin hormone on glucose absorption and metabolism in the human body? 2+3=5
Or
Write three differences between binocular vision and monocular vision in the following areas:
• Reflection structure of objects
• Field of view
• Depth
Identify the difference between innate and acquired reflexes in any two of the following ways:
• Nature
• Condition
• Previous experience
• Neural pathway
3+2=5
4.4 Show the genetic sequence of ferns through a diagram. 5
Or
Show the sexual reproduction method of flowering plants through diagrams. 5.
4.5 Identify the following three differences between mitosis and meiosis:
• Location of execution
• Nature of chromosome division
• Number of cells produced
Explain the following events related to meiosis cell division:
• Separation of chromosomes and chromatids
• Crossing-over 3+2=5
Or
Identify the following differences between plant cell cytokinesis and animal cell cytokinesis:
• Method
• Time of onset
• Role of Golgi apparatus
Establish the relationship between genes, DNA, and chromosomes. 3+2=5
4.6 What are the possible genetic consequences in the following cases:
• One of the parents is thalassemic and the other is a carrier of the thalassemia gene
• Both the father and mother are carriers of the thalassemia gene
What are the symptoms of thalassemia? 2+3=5
Or
Show with the help of a table the three pairs of contrasting traits of pea seeds selected by Mendel.
Show the sex determination process in humans using a checker board. 3+2=5
Category — ‘E’
(For external candidates only)
5. Answer any 4 questions: 1 x 4 = 4
5.1 Write one characteristic of yoga.
5.2 Which cell organelle is called the ‘powerhouse’ of the cell?
5.3 Write a function of collenchyma.
5.4 Give an example of a bird-pollinated flower.
5.5 Give an example of a carbohydrate-digesting enzyme.
6. Answer any three questions: 2 x 3 = 6
6.1 Name the two structural parts of a nerve cell.
6.2 Write the names of two non-nitrogenous excretory substances of plants.
6.3 Write one function each of ribosome and lysosome.
6.4 Write the names of two endangered animals of West Bengal.