Maximum Marks: 80
Time allowed: Two and half hours
Answers to this Paper must be written on the paper provided separately.
You will not be allowed to write during first 15 minutes.
This time is to be spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section-A
(Attempt all questions from this Section.)
Question 1
Choose one correct answer to the questions from the given options:
(Do not copy the question,write the correct answers only)
(i) The Loops of Henle lie in
(a) Renal Cortex
(b) Renal Medulla
(c) Renal Pelvis
(d) Renal Artery
Solution
Option (b) - Loops of Henle lie in Renal Medulla
(ii) The antiseptic present in tears:
(a) Iodine
(b) Hydrogen peroxide
(c) Lysozyme
(d) Lysosome
Solution
Option (c) -Lysozyme is the antiseptic present in tears
(iii) Assertion (A): The foetus respires but does not breathe.
Reason (R): The maternal blood supplies oxygen to the foetus through placenta.
(a) A is True and R is False
(b) A is False and R is True
(c) Both A and R are True
(d) Both A and R are False
Solution
Option (c) - Both A and R are True
(iv) During ventricular systole, the atrioventricular valves (P) ____
and semilunar valves (Q) _____
(a) P-close, Q— Open
(b) P-close, Q— Close
(c) P—open, Q- Close
(d) P—open, Q- Open
Solution
Option (a) - P- close, Q-Open
(v) The two cerebral hemispheres are joined by a sheet of fibres called:
(a) Pons
(b) Corpus luteum
(c) Hypothalamus
(d) Corpus callosum
Solution
Option (d) - Corpus callosum connects the two cerebral hemispheres
(vi) The onset of menstruation in a human female is called:
(a) Menopause
(b) Menarche
(c) Ovulation
(d) Oogenesis
Solution
Option (b) - Menarche refers to the onset of menstruation in human
females
(vii) Assertion (A): Rods and Cones are photoreceptors in the sclera of
eyeball.
Reason (R): Rods are sensitive to dim light.
(a) A is True and R is False.
(b) A is False and R is True.
(c) Both A and R are True.
(d) Both A and R are False.
Solution
Option (b) - A is False and R is True
(viii) Priya tried to match the hormones with their effect on the human body.
She tabulated the pairs as follows:
Identify the correct pair of hormones.
(a) P-—Insulin, Q— Glucagon.
(b) P-Adrenaline, Q-—- Oxytocin.
(c) P-—Glucagon, Q—- Vasopressin.
(d) P-—Vasopressin, Q— Adrenaline.
Solution
Option (c) - P- Glucagon, Q -Vasopressin
(ix) While studying the stages in the evolution of man, a well-developed chin
is observed in
(a) Homo habilis
(b) Homo erectus
(c) Homo sapiens
(d) Australopithecus
Solution
Option (c) - Homo sapiens exhibit a well-developed chin
(x) A pair of corresponding chromosomes of the same shape, size and one
from each parent is called:
(a) Autosomes
(b) Allosomes
(c) Analogous chromosomes
(d) Homologous chromosomes
Solution
Option (d) - Homologous chromosomes refer to the pair of corresponding
chromosomes of the same shape, size and one from each parent
(xi) Assertion (A): We urinate more in summer.
Reason (R): Sweat glands are more active in summer.
(a) A is True and R is False
(b) A is False and R is True
(c) Both A and R are True
(d) Both A and R are False
Solution
Option (b) - A is False and R is True
(xii) Rahul inserted a hairpin into his right ear to remove ear wax. He felt a
sudden sharp pain with loss of hearing. This was due to:
(a) Rupture of eardrum
(b) Rupture of vestibule
(c) Rupture of cornea
(d) Rupture of pinna
Solution
Option (a) - Rupture of eardrum results in sharp pain with loss of hearing
(xiii) Assertion (A): All food chains begin with herbivores.
Reason (R): Green plants are heterotrophs.
(a) A is True and R is False
(b) A is False and R is True
(c) Both A and R are True
(d) Both A and R are False
Solution
Option (d) - Both A and R are False
(xiv) A biology teacher asked her students to give two examples of vestigial
organs in the human body.
Raj said: Wisdom teeth and Pinna
Sonu said: Body hair and large intestine
Lata said: Vermiform appendix and wisdom teeth
Abhay said: Pinna and Ossicles
Who were correct?
(a) Abhay and Sonu
(b) Sonu and Lata
(c) Raj and Lata
(d) Abhay and Raj
Solution
Option (c) - Raj and Lata have given the examples of vestigial organs
(wisdom teeth, pinna and vermiform appendix)
(xv) During a practical exam, a plant cell in a particular solution was placed
under a compound microscope. Students were told to observe the cell and
name the tonicity of the solution and mention the process that occurred
in the cell.
(a) Isotonic, Endosmosis
(b) Hypotonic, Active Transport
(c) Hypertonic, Endosmosis
(d) Hypertonic, Exosmosis
Solution
Option (d) - Hypertonic, Exosmosis
Question 2
(i) Name the following:
(a) The basic units of heredity.
(b) The undesirable change in the environment leading to its
deterioration.
(c) The structure that connects placenta and the human foetus.
(d) The statistical study of human population.
(e) The nitrogenous base that pairs with adenine.
(ii) Given below is the transverse section of the spinal cord. Read the
information below the diagram and fill in the blanks:
The spinal cord extends from the medulla oblongata of the brain and runs
down through the whole length of the vertebral column. The spinal cord
is covered by the meninges. It conducts impulses from the skin and
muscles to the brain. It also conducts impulses from the brain to the
muscles of the trunk and limbs.
The spinal cord is a part of the (a) ____ Nervous System. The
grey matter in the picture given above consists of (b) ____ while
the white matter consists of (c) _____ . The spinal cord is concerned
with the (d) ____ actions below the neck. (e) ___ is the bony structure that protects the spinal cord.
(iii) Arrange and rewrite the terms in each group in the correct order so as to be in a logical sequence beginning with the term that is underlined.
(a) Apical meristem, Positive phototropism, Auxins, Cell elongation.
(b) Urethra, Urinary bladder, Ureter, Kidney.
(c) Auditory canal, Organ of Corti, Stapes, Malleus.
(d) Cell membrane, Chromatin fibres, Cell wall, Cytoplasm.
(e) Lungs, Right auricle, Inferior venacava, Pulmonary Artery.
(iv) Read the explanations given below and name the structure:
Example: The largest gland in the human body that secretes bile.
Answer: Liver.
(a) Food conducting tissue in vascular plants.
(b) Acell formed by the fusion of gametes.
(c) The smallest blood vessels in the human body.
(d) A tubular passage that connects the pharynx and the middle ear.
(e) The openings on the barks of trees through which transpiration
occurs.
(v) Given below is a cross section of the human eye. Match the structures
marked (a) to (e) with their correct functions:
Example: (f) - 6. Holds the lens in position
Solution
(i)(a) Genes refer to the basic units of heredity
(b) Pollution is the undesirable change in the environment leading to its
deterioration
(c) Umbilical Cord is the structure that connects placenta and the human
foetus
(d) Demography refers to the study human population
(e) Thymine pairs with adenine
(ii) The spinal cord is a part of the (a) Central Nervous System. The grey matter
in the picture
given above consists of (b) cytons/ nerve cell bodies while the white
matter consists of
(c) axons/ nerve cell fibres. The spinal cord is concerned with the (d)
reflex actions below
the neck. (e) Vertebral column is the bony structure that protects the spinal
cord.
(iii) (a) Auxins →Apical meristem →Cell elongation →Positive phototropism
(b) Kidney →Ureter →Urinary bladder →Urethra
(c) Auditory canal →Malleus →Stapes →Organ of Corti
(d) Chromatin fibres →Cytoplasm →Cell membrane →Cell wall
(e) Inferior vena cava →Right auricle →Pulmonary Artery →Lungs
(iv) (a) Phloem - is the food conducting tissue in vascular plants
(b) Zygote - refers to the cell formed by fusion of gametes
(c) Capillaries - refer to the smallest blood vessels in the human body
(d) Eustachian Tube - It is the tubular passage connecting the pharynx and
the middle ear
(e) Lenticels - are the openings on the barks of trees through which
transpiration occurs
(v) (a) - 5. Transmits nerve impulses to brain
(b) - 1. Protects retina
(c) - 2. Regulates the size of the pupil
(d) - 4. Keeps the lens moist
(e) - 3. Alters the shape of the lens
Section-B
(Attempt any four questions from this Section.)
Question 3
(i) Explain the term — Active transport.
(ii) Name the structures through which Transpiration and Guttation occur in
a plant.
(iii) How does the rate of Transpiration differ when there is:
(a) High temperature
(b) High humidity
(iv) Write the overall chemical equation for Photosynthesis.
(v) Sam observed a slide containing the lower epidermis of a leaf under a
microscope. A number of tiny openings between the epidermal cells
were present as shown below in the diagram:
(a) What are these tiny openings called?
(b) Name the cells that regulate the opening and closing of the:
structures.
(c) Which ion is responsible for the opening and closing of the:
openings?
Solution
(i) Active transport refers to the passage of a substance (salt or ion) from its
lower to higher concentration through a living cell membrane using energy
from the cell.
(ii) The process of transpiration occurs through stomata, lenticels and cuticle
whereas the process of guttation occurs through hydathodes.
(iii) The rate of transpiration differs as a result of:
(a) High temperature — The rate of transpiration increases with increase in
temperature.
(b) High humidity — The rate of transpiration decreases with increase in
humidity.
(iv) The overall equation of photosynthesis is as follows:
(v) According to the observation:
(a) These tiny openings are called stomata.
(b) Guard cells regulate opening and closing of the stomatal structures.
(c) Potassium ions are responsible for the opening and closing of these
structures.
Question 4
(i) Why is Adrenaline called ‘The Emergency Hormone’?
(ii) Expand the abbreviation — ADH. Give one example of a diuretic
substance.
(iii) Mention the significance of the following minerals:
(a) Iodine in our food.
(b) Magnesium for green plants.
(iv) State two objectives of Swachh Bharat Abhiyan.
(v) Draw a neat, labelled diagram of a root hair.
Solution
(i) Adrenaline is known as the emergency hormone as it prepares the body to
meet any emergency situation, for "fight" i.e. to face danger or for "flight" i.e.
to run away from it. The extra energy and strength is provided to the body in
that situation. It stimulates the sympathetic nervous system. When excited or
angry, the adrenal medulla prepares the body to face any emergency situation.
(ii) ADH - stands for Antidiuretic Hormone. Example: caffeine, coconut water,
alcohol (any one)
(iii) The significance is as follows:
(a) Iodine is required for the synthesis of thyroxine by thyroid gland.
(b) Magnesium is required for the synthesis of chlorophyll.
(iv) The two objectives of Swachh Bharat Abhiyan are:
To eliminate open defecation: The mission aims to ensure that all
households have access to toilets and promote the construction and use
of sanitary latrines.
1.
To promote cleanliness and hygiene: It seeks to create awareness about
sanitation and cleanliness practices, improve waste management systems,
and maintain cleanliness in public spaces.
2.
(v) Labelled diagram of a root hair :
Question 5
(i) Mention one characteristic of roots for absorbing water from the soil.
(ii) What is Parthenocarpy? Give one example.
(iii) State the difference between Micturition and Parturition.
(iv) Write any two functions of Lymph.
(v) Study the picture given below and answer the questions:
(a) How does water get polluted?
(b) What is the effect of water pollution on human life?
(c) Mention one control measure to stop the pollution of water bodies.
Solution
(i) The root hairs have thin cell walls which allows easy entry of water in the
root hairs from the soil and also provide an enormous surface area for water
absorption.
(ii) Parthenocarpy refers to the phenomenon in plants by which fruits develop
without fertilization of ovules. So, fruits are formed without the need for
pollination and fertilization.
Example: apples, bananas, tomatoes (any one)
(iii)
(iv) The lymphatic functions are as follows:
1. It drains excess tissue fluid into blood.
2. It helps in absorption of fats from the intestine.
(v) According to the given picture:
(a) Water gets polluted due to:
• Sewage, oil spills and industrial effluents releasing pollutants such as
chemicals, heavy metals, and toxins into the water bodies.
(b) The contaminated water can carry pathogens such as bacteria, viruses, and
parasites that cause diseases like cholera, dysentery, typhoid, etc.
(c) The harmful pollutants and contaminants can be significantly reduced by
ensuring that all industrial, agricultural, and municipal sewage is treated before
being released into water bodies.
Question 6
(i) State Mendel’s Law of Segregation
(ii) What are Tropic hormones? Give one example
(iii) Differentiate between the terms Phenotype and Genotype
(iv) What is the significance of Testes being placed in Scrotal sacs?
(v) Draw a neat, labelled diagram of a human sperm.
Solution
(i) During gamete formation (sperm or eggs), the two alleles for a given gene
separate, or segregate, so that each gamete carries only one allele for each
gene.
(ii) Tropic hormones refer to the hormones that stimulate other endocrine
glands to secrete their specific hormones.
Example: TSH (Thyroid Stimulating Hormone) activates thyroid to secrete
thyroxine.
(iii)
(iv) The testes are responsible for the production of male gametes i.e., sperms.
The normal body temperature does not allow the maturation of the sperms.
Being suspended outside the body cavity, the temperature in the scrotal sac is
2 to 3°C less than that of the body which is the suitable temperature for the
maturation as well as for the survival of the sperms.
(v) Labelled diagram of a human sperm:
Question 7
(i) What is the scientific name of the pea plant that Mendel used for his
experiments?
(ii) Mention the surgical methods of contraception in:
(a) Men
(b) Women
(iii) Name two harmful effects of noise pollution.
(iv) Which parts of a plant exhibit:
(a) Negative Geotropism
(b) Positive Hydrotropism
(v) Kathak is an Indian classical dance which involves a lot of spinning by
the dancers. The learners of this dance experience dizziness in the
beginning while spinning.
(a) Name the part of the membranous labyrinth responsible for this
dizziness.
(b) Give a suitable reason for your answer.
(c) Mention the nerve that carries the impulse for dizziness to the brain.
Solution
(i) Pisum Sativum is the scientific name of the plant that Mendel used for his
experiments.
(ii) The surgical methods of contraception are as follows:
(a) Men - Vasectomy
(b) Women - Tubectomy
(iii) The two harmful effects of noise pollution are as follows:
• Disturbs sleep.
• Interrupts concentration of thoughts
(iv) The part of the plant which exhibit:
(a) Negative Geotropism - Shoot
(b) Positive Hydrotropism - Root
(v) According to the given case:
(a) Semicircular canals are responsible for the dizziness caused.
(b) As the fluid in the semi-circular canals continue to spin for a short time
even after the dancer stops which thereby results in dizziness.
(c) Auditory nerve is responsible for carrying the impulse for dizziness to the
brain
Question 8
(i) How does Transpiration help in the uptake of water from the soil?
(ii) Given below are two statements which are incorrect. Rewrite the correct
statements:
(a) Fresh water fish when placed in hypertonic salt solution absorb
water and burst.
(b) Seminiferous tubules secrete Testosterone.
(ili) During Mitosis what is the position of chromatids in:
(a) Metaphase
(b) Anaphase
(iv) Chris was watching the display of fireworks in the sky.
(a) Trace the path of the light rays using the following terms:
Fovea, Lens, Conjunctiva, Pupil, Cornea
(b) Name the nerve that carries the impulse for vision to the brain.
(v) Draw a neat, labelled diagram of a Malpighian Capsule.
Solution
(i) The process of transpiration is the one by which water is lost from the plant,
primarily through small openings called stomata on the leaves. As water
evaporates from the leaf surfaces, it creates a suction force that pulls water
upward from the roots through the xylem vessels.
(ii) The correct statements are as follows:
(a) Freshwater fish when placed in a hypertonic salt solution lose water and
may shrink.
OR
Marine fish, when placed in hypotonic salt solution, absorb water and burst.
(b) Seminiferous tubules are involved in the production of sperm.
OR
Leydig cells secrete Testosterone.
(iii) The position of chromatids during the given phases:
(a) Metaphase - In the equatorial plane.
(b) Anaphase - Sister chromatids separate and move towards opposite poles.
(iv) According to the given case:
(a) The light rays will follow the given path:-
Conjunctiva → Cornea → Pupil → Lens → Fovea
(b) Optic Nerve is responsible for carrying the impulse for vision to the brain.
(v) Labelled diagram of a Malpighian Capsule