ICSE Class 10 Biology — 2014 Paper

(i) Cerebrum

(ii) Malleus

(iii) Recessive gene

(iv) Insulin and Glucagon

(v) Photophosphorylation

(i) Cerebrospinal fluid acts like a cushion and protects the brain from shocks.

(ii) Eustachian tube equalises the pressure on either side of the ear drum.

(iii) Suspensory ligament holds the lens in position.

(iv) Sperm duct serves to transport sperm from the epididymis to urethra.

(v) Lenticels facilitate transpiration in older stems.

The human female gonads are ovaries. A maturing egg in the ovary is present in a sac of cells called ovarian follicle (1). As the egg grows larger, the follicle enlarges and gets filled with a fluid and is now called the Graafian (2) follicle. The process of releasing the egg from the ovary is called ovulation (3). The ovum is picked up by the oviducal funnel and fertilisation takes place in the oviduct (4). In about a week, the blastocyst gets fixed in the endometrium of the uterus and this process is called implantation (5).

(i) Odd term: Glucagon
     Category: Pigments

(ii) Odd term: Uterus
    Category: Parts of excretory system.

(iii) Odd term: Phagocytosis
    Category: Processes in plants

(iv) Odd term: Photon
     Category: Parts of a neuron.

(v) Odd term: Insulin
     Category: Female reproductive / sex hormones.

(i) Transpiration.

(ii) Transpiration is the process in which water is lost in the form of vapour from the aerial parts of the plant.

(iii) Weight of test tube A before the experiment was more than its weight after the experiment. This is because water from test tube A has evaporated due to transpiration.
Weight of test tube B remains the same before and after the experiment, because no loss of water occurs in test tube B as there is no plant and the oil on the surface prevents direct evaporation of water.

(iv) It is a control experiment where the purpose of using test tube B is to compare the level of water in both test tubes.

(i) Hyposecretion of thyroxin

(ii) Salivation at the sight of food

(iii) 44 + xx chromosome

(iv) Fungus

(v) Epididymis

(i) Tricuspid valve is located between right auricle and right ventricle.

(ii) Amnion covers the foetus in the uterus.

(iii) Yellow spot lies at the back of the eye almost at the centre on the horizontal axis of the eyeball.

(iv) Seminal vesicles are located between the posterior surface of the urinary bladder and the rectum in human males.

(v) Adrenal glands are located on top of both kidneys like caps.

(i) Difference between Spinal nerves and Cranial nerves (number of nerves)

(ii) Difference between near vision and Distant vision (shape of the eye lens)

(iii) Difference between Corpus callosum and Corpus luteum (function)

(iv) Difference between Turgor pressure and Wall pressure (explain)

(v) Difference between Disinfectant and Antiseptic (definition)

(i) The blood vessels labelled 1 and 2 are:

• 1 → Anterior / Superior venacava
• 2 → Dorsal aorta

(ii) Function of blood vessels —

• 5 → Supply oxygenated blood to liver.
• 8 → Carries deoxygenated blood from the posterior parts of the body to the right auricle of the heart.

(iii) Blood vessel 6 is called Hepatic portal vein. It carries deoxygenated blood from intestine to liver. This blood contains excess glucose, some toxic substances etc. which are sent to liver where they are detoxified and the excess glucose is converted to glycogen and stored. This prevents these substances from directly entering and damaging the heart.

(iv) Hepatic portal vein (i.e., blood vessel 6) contains a high amount of glucose and amino acids after a meal.

(v) Below diagram shows the different blood cells as seen in a smear of human blood:

(i) The technical terms of the solutions used in beakers 1, 2 and 3 are:
Beaker 1 — Hypotonic solution.
Beaker 2 — Hypertonic solution.
Beaker 3 — Isotonic solution.

(ii) In beaker 3, the solution present is an isotonic solution, i.e. the relative concentration of water molecules and solutes is the same in the solution as well as inside the cell. There is no movement of water molecules across the cell membrane. Hence, the size of potato cubes remains the same.

(iii) The cell sap of root hair has a higher concentration of solute than the surrounding water. Due to this endosmosis takes place helping the root hairs in absorption of water.

(iv) Osmosis is the movement of water molecules from their region of higher concentration (dilute solution or with a lower solute concentration) to their region of lower concentration (concentrated solution or with a higher solute concentration) through a semi-permeable membrane.

(v) The cell wall is freely permeable to all substances, while the cell membrane is selectively permeable and allows only certain substances to enter or exit the cell.

(i) The above experiment is conducted to show that Sunlight is necessary for photosynthesis.

(ii) The plant was placed in the dark before beginning the experiment to destarch the leaves.

(iii) The leaf was boiled in water to kill the cells and boiled in methylated spirit to remove chlorophyll.

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

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

(v) Below is the labelled diagram of a chloroplast:

(i) The phenomenon that is depicted here is the reflex action.

(ii) The term for the point of contact between the two nerve cells is called the Synapse.

(iii) The parts 1, 2, 3 and 4 are:

• 1 → Sensory / Afferent neuron
• 2 → Dorsal ganglion / Dorsal root
• 3 → White matter
• 4 → Grey matter

(iv) Below are the functions of parts 5 and 6:

• The function of 5 (Synapse) — It transmits the sensory impulse from sensory neurons to the motor neurons.
• The function of 6 (Motor neuron / Efferent neuron) — It transmits the command to the effectors part (e.g. muscles).

(v) The arrangement of neurons in the spinal cord differs from that of the brain. In the brain, Gray matter is present on the outside and white matter on the inner side. In Spinal cord, white matter is present on the outside and Gray matter on the inner side.

(i) Chlorofluorocarbons (CFC) are one of the major causes for ozone depletion. Hence they are banned in many countries.

(ii) Cone cells in the retina are responsible for colour vision. They are functional only in bright light. Moon light is unable to stimulate the cone cells. However, the rod cells respond to dim light. Hence, we can see in moon light but cannot distinguish colours.

(iii) In case of balsam plants, the rate of transpiration during mid-day exceeds the rate of absorption of water by the roots. The cells therefore lose turgidity. In the evening or during the night, the stomata are constricted and the temperature is not very high. Therefore, there is no loss of water through transpiration, and the turgidity of the leaves is re-acquired.

(iv) Haemoglobin has very strong affinity for Carbon Monoxide forming a stable compound Carboxyhaemoglobin (HbCO). This cuts down the capacity of the blood of transporting Oxygen, sometimes resulting in death. Hence, Carbon monoxide is highly dangerous when inhaled.

(v) Alcohol affects the cerebellum part of the brain which is responsible for muscular co-ordination. So after consuming alcohol the cerebellum is unable to coordinate muscular movements properly resulting in the person walking clumsily.

(i) Plant cell.
Reason — Cell wall present and Centrioles absent.

(ii) Prophase.

(iii) Metaphase follows the prophase. The chromosomes will be arranged at the equator attached to the spindle fibre.

(iv) In Mitosis — The chromosome number in the daughter cell remains the same as that of the parent cell.
In Meiosis — Daughter cells receive only half the number of chromosomes from the parent cells.

(v) Below labelled diagram shows a duplicated chromosome:

(i) The vaccines are given for:

1. Salk's vaccine → Poliomyelitis
2. BCG → Tuberculosis

(ii) One example of each are:

1. A water pollutant → Sewage
2. An aquatic plant used in the lab to demonstrate O₂ liberation during photosynthesis → Hydrilla.
3. An antibiotic → Penicillin
4. A nitrogenous base in DNA → Adenine

(iii) The full forms are:

1. ATP → Adenosine Triphosphate.
2. TSH → Thyroid Stimulating Hormone.
3. DPT → Diphtheria Pertussis Tetanus.
4. DNA → Deoxyribonucleic Acid.

(i) The parts 1, 2, 3 and 4 are:

• 1 → Collecting duct.
• 2 → Distal convoluted tubule.
• 3 → Loop of Henle.
• 4 → Bowman's capsule.

(ii) The efferent arteriole is narrower than the afferent arteriole. This creates a high hydrostatic pressure in the glomerulus.

(iii) Efferent arteriole.

(iv) Two main stages of urine formation are:

1. Ultrafiltration.
2. Selective Reabsorption.

(v) Henle's loop and Collecting tubules

(i) A cross between two parents taking the alternative traits of one single character. For example, a cross between tall and dwarf pea plants.

(ii) Biomedical waste refers to the waste from medical services such as needles, syringes, dirty dressings, unused discarded medicinal tablets and powders, used surgical instruments, etc.

(iii) Immunity which is by birth, i.e., acquired from parents, is called Innate immunity.

(iv) The process in which WBCs (specially monocytes and neutrophils) produce pseudopodia and migrate through the walls of the blood vessels into the tissues to fight against disease causing germs is termed as Diapedesis.

(v) Hormones are secretions from some glandular part of the body, that is poured directly into blood and that acts on the target organs or cells of the same individual, bringing about coordination between distant parts of the body.

(i) Two harmful effects of noise pollution are:

1. It lowers efficiency of work.
2. It disturbs sleep and leads to nervous irritability.

(ii) The activities are categorized below:

1. To suggest quarantine measures to prevent spread of disease. → WHO
2. Humanitarian services to victim of war. → Red Cross
3. To educate people in accident prevention. → Red Cross
4. To promote projects for research on disease. → WHO

(iii) Two major reasons for the population explosion in India are —

1. Desire for a male child.
2. Illiteracy and Lack of awareness about birth control measures.

(iv) Law of Segregation (also called the law of purity of gametes) — The two members of a pair of factors separate during the formation of gametes. They do not blend but segregate or separate into different gametes. The gametes combine together by random fusion at the time of zygote formation.

(i) Vasectomy

(ii) Demography

(iii) Pericardium

(iv) Mutation

(v) Nucleotide

(vi) Plasma

(vii) Auditory nerve

(viii) Tropic hormones

(ix) Scrotum

(x) Menopause.