Solved 2015 Question Paper ICSE Class 10 Biology

Section I (40 Marks)

Question 1(a)

Name the following: [5]

(i) The process of uptake of mineral ions against the concentration gradient using energy from cell.

(ii) The form in which glucose is stored in liver.

(iii) The vein that carries oxygenated blood.

(iv) The cross between two parents having one pair of contrasting characters.

(v) The structure formed by the villi of the embryo and the uterus of the mother.

Answer

(i) Active Transport

(ii) Glycogen

(iii) Pulmonary vein

(iv) Monohybrid cross

(v) Placenta

Question 1(b)

The statements given below are False. Rewrite the correct form of the statement by changing the word which is underlined: [5]

(i) Alpha cells of pancreas secrete Insulin.

(ii) Formalin is an example of an Antiseptic.

(iii) CNG is mainly responsible for the formation of acid rain.

(iv) Sulphadiazine is an example of an Antiseptic

(v) Cretinism is caused due to deficiency of Adrenaline

Answer

(i) Alpha cells of pancreas secrete Glucagon.

(ii) Formalin is an example of a Disinfectant.

(iii) Fossil fuel is mainly responsible for the formation of acid rain.

(iv) Sulphadiazine is an example of a sulphonamide.

(v) Cretinism is caused due to deficiency of Thyroxine.

Question 1(c)

Choose the correct answer from the four options given below: [5]

(i) A single highly coiled tube where sperms are stored, gets concentrated and mature is known as:

1. Epididymis
2. Vas efferentia
3. Vas deferens
4. Seminiferous tubule.

(ii) Chromosomes get aligned at the center of the cell during:

1. Metaphase
2. Anaphase
3. Prophase
4. Telophase

(iii) BCG vaccine is effective against:

1. Cholera
2. Mumps
3. Tuberculosis
4. Measles

(iv) Which one of the following is mainly associated with the maintenance of the posture?

1. Cerebrum
2. Cerebellum
3. Thalamus
4. Pons

(v) An example of non-biodegradable waste is:

1. Vegetable peels
2. Sewage
3. Livestock waste
4. DDT.

Answer

(i) Epididymis.

(ii) Metaphase

(iii) Tuberculosis

(iv) Cerebellum

(v) DDT

Question 1(d)

Mention the exact location of the following structures: [5]

(i) Thylakoids

(ii) Organ of Corti

(iii) Lenticels

(iv) Bicuspid valve

(v) Loop of Henle.

Answer

(i) Thylakoids are located in grana of chloroplast.

(ii) Organ of Corti is present in the middle cochlear canal of the ear.

(iii) Lenticels are present on the surface of old woody stems.

(iv) Bicuspid valve is located between left auricle and left ventricle.

(v) Loop of Henle runs in the medulla to turn back and to re-enter the cortex to continue into the next convoluted region of the tubule.

Question 1(e)

The diagram given below represents a certain stage of mitosis: [5]

(i) Identify the stage of cell division.

(ii) Name the parts labelled A and B.

(iii) What is the unique feature observed in this stage?

(iv) How many daughter cells are formed from this type of cell division?

Answer

(i) Anaphase

(ii) The parts labelled A and B are:

• A → Spindle fibre
• B → Centromere

(iii) Chromosomes are seen moving towards the poles.

(iv) Two daughter cells.

Question 1(f)

Given below is an example of a certain structure and its special functional activity. On a similar pattern fill in the blanks with suitable functions: [5]

Example: Chloroplast and Photosynthesis

(i) Xylem and ...............

(ii) Ciliary Body and ...............

(iii) Seminiferous Tubule and ...............

(iv) Thyroid gland and ...............

(v) Eustachian Tube and ...............

Answer

(i) Xylem and upward transport of water and minerals.

(ii) Ciliary Body and alters the focal length of lens.

(iii) Seminiferous Tubule and production of sperms.

(iv) Thyroid gland and secretion of Thyroxine for regulation of basal metabolism.

(v) Eustachian Tube and equalizes air pressure on either side of ear drum.

Question 1(g)

Rewrite and complete the following sentences by inserting the correct word in the space indicated: [5]

(i) The phenomenon of loss of water through a cut stem or injured part of plant is called ................

(ii) ............... is the scientific name of garden pea, which Mendel used for his experiments.

(iii) A fluid that occupies the larger cavity of the eye ball behind the lens is ................

(iv) Oxygen combines with haemoglobin present in RBC and forms ................

(v) ............... causes corrosion of the marble or brick surface.

Answer

(i) The phenomenon of loss of water through a cut stem or injured part of plant is called Bleeding.

(ii) Pisum Sativum is the scientific name of garden pea, which Mendel used for his experiments.

(iii) A fluid that occupies the larger cavity of the eye ball behind the lens is Vitreous humour .

(iv) Oxygen combines with haemoglobin present in RBC and forms Oxyhaemoglobin.

(v) Acid rain causes corrosion of the marble or brick surface.

Question 1(h)

Match the items in Column 'A' with those which are most appropriate in Column 'B'. [5]

Rewrite the matching pairs as shown in the example:
Example: Fibrinogen – Clotting of blood.

Answer

Section II (40 Marks)

Question 2(a)

The diagram below shows two test-tubes A and B. Test-tube A contains a green water plant. Test-tube B contains both a green water plant and a snail. Both test-tubes are kept in sunlight. Answer the questions that follow: [5]

(i) Name the physiological process that releases the bubbles of oxygen.

(ii) Explain the physiological process as mentioned above in Q.2(a)(i).

(iii) What is the purpose of keeping a snail in test-tube 'B'?

(iv) Why does test-tube 'B' have more bubbles of oxygen?

(v) Give an example of a water plant that can be used in the above experiment.

(vi) Write the overall chemical equation for the above process.

Answer

(i) Photosynthesis

(ii) Photosynthesis is the process by which living plant cells, containing chlorophyll, produce food substances (glucose and starch), from carbon dioxide and water, by using light energy. Plants release oxygen as a by-product during photosynthesis.

(iii) The snail respires and releases Carbon dioxide so more Carbon dioxide is available to the plant for photosynthesis.

(iv) Test tube B have more bubbles of Oxygen because the rate of photosynthesis is more in test tube B as the plant gets more CO₂ from the snail.

(v) Hydrilla is a water plant which is used for such experiments.

(vi) Balanced chemical equation representing the process of photosynthesis is given below:

$6CO_2 + 12H_2O \space \space \overset{\text{light energy}}{\underset{\text{chlorophyll}}{\longrightarrow}} \space \space C_6H_{12}O_6 + 6H_2O + 6O_2 \uparrow$

Question 2(b)

Give the biological / technical terms for the following: [5]

(i) A mixture of smoke and fog.

(ii) Capacity of our body to resist diseases.

(iii) Fixing of developing zygote on the uterine wall.

(iv) The permanent stoppage of menstruation at about the age of 45 years in a female.

(v) The hormone increasing reabsorption of water by kidney tubules.

(vi) A thin membrane covering the entire front part of the eye.

(vii) The lens of eye losing flexibility resulting in a kind of long-sightedness in middle aged people.

(viii) The number of persons living per square kilometre at any given time.

(ix) The sound produced when the atrio-ventricular valves close in the heart.

(x) The process by which white blood cells engulf bacteria.

Answer

(i) Smog

(ii) Immunity

(iii) Implantation

(iv) Menopause

(v) Antidiuretic hormone (ADH) / Vasopressin

(vi) Conjunctiva

(vii) Presbyopia

(viii) Population Density

(ix) LUBB

(x) Phagocytosis

Question 3(a)

An apparatus as shown below was set up to investigate a physiological process in plants. The setup was kept in sunlight for two hours. Droplets of water were then seen inside the bell jar. Answer the questions that follow: [5]

(i) Name the process being studied.

(ii) Explain the process named above in Q.3 (a) (i).

(iii) Why was the pot covered with a plastic sheet?

(iv) Suggest a suitable control for this experiment.

(v) Mention two ways in which this process is beneficial to plants.

(vi) List three adaptations in plants to reduce the above mentioned process.

Answer

(i) Transpiration

(ii) Transpiration is the loss of water in the form of water vapour from the aerial parts of the plants like leaves, stems, etc. The water vapour is released from tiny openings called stomata, present on the aerial parts of the plant.

(iii) The pot is covered with a plastic sheet to prevent evaporation of water from the soil.

(iv) A control for this experiment will be an empty polythene bag with its mouth tied and kept in sunlight. It will show no droplets of water inside.

(v) Transpiration is beneficial to plants in the following ways:

1. It creates a suction force in the stem which enables the roots to absorb water and minerals.
2. It helps in cooling the plant in hot weather.

(vi) Three adaptations in plants to reduce transpiration are:

1. Sunken stomata.
2. Narrow leaves.
3. Reduced exposed surface by rolling or folding of leaves.

Question 3(b)

Briefly answer the following questions: [5]

(i) State two reasons for the increase of population in India.

(ii) What is the significance of amniotic fluid?

(iii) What is the function of ear ossicles?

(iv) Mention any two activities of the WHO.

(v) State Mendel's law of Dominance.

Answer

(i) The two main reasons for the rapid increase of population in India are —

1. Illiteracy — Most of the rural population which forms the bulk of our society are still illiterate, ignorant, and follow various superstitions. They also do not know the functioning of the human reproductive system.
2. Economic reasons — Children are considered to be helping hands to increase family income.

(ii) Amniotic fluid fills the space between the amnion and the embryo. It's important functions are:

1. It keeps even pressure all around the embryo.
2. It prevents sticking of the foetus to the amnion.

(iii) The ossicles increase the intensity of the sound vibrations received by the tympanum and transmit them to the inner ear.

(iv) Two activities of the WHO —

1. To collect & supply information about occurrence of diseases of epidemic nature.
2. To promote and support projects for research on diseases.

(v) Law of Dominance — Out of a pair of contrasting characters present together, only one is able to express itself while the other remains suppressed. The one that expresses is the dominant character and the one that is unexpressed is the recessive one. The recessive character can express only when the pair consists of both recessives (homozygous recessive).

Question 4(a)

The diagrams given below are cross sections of blood vessels: [5]

(i) Identify the blood vessels A, B and C.

(ii) Name the parts labelled 1 to 3.

(iii) Name the type of blood that flows through A.

(iv) Mention one structural difference between A and B.

(v) In which of the above vessels does exchange of gases actually take place?

Answer

(i) The blood vessels A, B, C are:

• A → Artery
• B → Vein
• C → Capillary

(ii) Parts labelled 1 to 3 are:

• 1 → Connective tissue / Tunica externa
• 2 → Lumen
• 3 → Muscular tissue / Tunica media

(iii) Oxygenated blood flows through A.

(iv) Arteries have narrow lumen whereas Veins have wide lumen.

(v) Capillary (i.e., blood vessel C marked above)

Question 4(b)

Differentiate between the following pairs on the basis of what is mentioned within brackets: [5]

(i) Diffusion and Osmosis (Definition)

(ii) RBC and WBC (Shape)

(iii) Tubectomy and Vasectomy (Part cut and tied)

(iv) Vasopressin and Insulin (Deficiency disorder)

(v) Rods and Cones of Retina (Type of pigment).

Answer

(i) Difference between Diffusion and Osmosis (Definition)

(ii) Difference between RBC and WBC (Shape)

(iii) Difference between Tubectomy and Vasectomy (Part cut and tied)

(iv) Difference between Vasopressin and Insulin (Deficiency disorder)

(v) Difference between Rods and Cones of Retina (Type of pigment).

Question 5(a)

The diagram given below shows a section of a human kidney. Study the diagram carefully and answer the questions that follow: [5]

(i) Label the parts numbered 1 to 4.

(ii) Why does part '2' have a striped appearance?

(iii) What is the fluid that passes down part '4'? Name the main nitrogenous waste present in it.

(iv) Mention the structural and functional units of kidneys.

(v) Name the two major steps in the formation of the fluid mentioned in Q. 5(a) (iii).

Answer

(i) The parts numbered 1 to 4 are:

• 1 → Cortex
• 2 → Medulla
• 3 → Pelvis
• 4 → Ureter

(ii) The medulla contains Henle's loop and collecting ducts that give it a striped appearance.

(iii) Urine passes down the Ureter. The main nitrogenous waste present in it is Urea.

(iv) Nephrons (also called uriniferous tubules, renal tubules, kidney tubules)

(v) The two major steps are —

1. Ultrafiltration
2. Selective Reabsorption.

Question 5(b)

Draw neat and labelled diagrams of the following: [5]

(i) Malpighian Capsule.

(ii) A Myelinated Neuron.

Answer

(i) Below labelled diagram shows Malpighian Capsule:

(ii) Below labelled diagram shows a Myelinated Neuron:

Question 6(a)

The diagram given below shows the male urinogenital system of a human being. Study the diagram and answer the questions that follow: [5]

(i) Label the parts numbered 1 to 8.

(ii) Name the corresponding structure of part (4) in female reproductive system.

(iii) What is the role of part 7?

Answer

(i) The parts numbered 1 to 8 are:

• 1 → Urinary bladder
• 2 → Ureter
• 3 → Prostate gland
• 4 → Vas deferens / Sperm duct
• 5 → Urethra
• 6 → Testis
• 7 → Scrotum / Scrotal sac
• 8 → Epididymis

(ii) Fallopian tube / Oviduct

(iii) Scrotum is a thin-walled sac of skin that protects and surrounds the testes. It also maintains the temperature of testes at 2 to 3°C less than body temperature for the maturation of sperms.

Question 6(b)

In a homozygous plant round seeds (R) are dominant over wrinkled seeds (r): [5]

(i) Draw a Punnett square to show the gametes and offspring when both the plants have heterozygous round seeds (Rr).

(ii) Mention the Phenotype and Genotype ratios of the offsprings in F₂ generation.

(iii) Name the sex chromosomes in human males and females.

(iv) Briefly explain the term 'Mutation'

(v) What is the number of chromosomes in the gametes of human beings?

Answer

(i) Below is the Punnett square board showing the gametes and offspring when both the parents have heterozygous round seeds:

(ii) Phenotype and Genotype ratios of the offsprings in F₂ generation are: Phenotype Ratio — 3 : 1
Genotype Ratio — 1 : 2 : 1

(iii) Sex chromosomes in human males and females are:
Males — XY
Females — XX

(iv) Mutation — Mutation is a sudden change in one or more genes, or in the number or in the structure of chromosomes. Mutation alters the hereditary material of an organism's cells and results in a change in certain characters or traits in an entire population and such changes can persist for years.

(v) Human gametes have 23 chromosomes.

Question 7(a)

The diagram below represents the human heart in one phase of its functions. Study the diagram carefully and answer the questions that follow: [5]

(i) Name the phase.

(ii) Which part of the heart is contracting in this phase? Give a reason to support your answer.

(iii) Name the parts labelled 1 to 4.

(iv) What type of blood flows through '2'?

(v) State the function of the part numbered '5'.

(vi) Name the membrane that covers the heart.

Answer

(i) Ventricular Systole.

(ii) Ventricle is contracting because both tricuspid and bicuspid valves are closed whereas both pulmonary semi-lunar and Aortic semi-lunar valves are open to pump the blood out of the two ventricles.

(iii) The parts labelled 1 to 4 are:

• 1 → Pulmonary Artery
• 2 → Aorta
• 3 → Bicuspid/Mitral valve
• 4 → Aortic Semilunar valve

(iv) Oxygenated blood

(v) Part numbered '5' are the Pulmonary Semilunar valves. They allow the deoxygenated blood to flow from the right ventricle to the lungs and prevents its backflow.

(vi) Pericardium

Question 7(b)

Explain the following terms: [5]

(i) Greenhouse effect.

(ii) Turgor pressure.

(iii) Selective reabsorption.

(iv) Natality.

(v) Pulse.

Answer

(i) The phenomenon by which certain gases specially CO₂ and methane (CH₄) accumulating in the atmosphere prevent the escape of heat, thereby warming the earth’s surface is known as Greenhouse effect.

(ii) The pressure of the cell contents on the cell wall is called Turgor pressure.

(iii) The glomerular filtrate entering the renal tubule is an extremely dilute solution containing a lot of useful materials such as glucose and some salts such as those of sodium. As this filtrate passes down the renal tubule, a lot of water along with these usable materials is reabsorbed. But their reabsorption is only to the extent that the normal concentration of the blood is not disturbed. This is called Selective Absorption.

(iv) Natality is the number of live births per thousand people per year.

(v) Pulse is the alternate expansion and elastic recoil of the wall of the artery during ventricular systole.