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(i) Three functions of WHO: 

(a) To direct and co-ordinate international health projects. 

(b) To encourage and conduct scientific research. 

(c) To organise international campaigns, to control and eliminate diseases like AIDS. 

(ii) Three advantages of a small family: 

(a) Children get proper education, 

(b) Children can get proper medical facilities. 

(c) Children can get proper diet and nutrition. 

(iii) (1) Population density: The sum total of individuals in a given geographic region at a specified period is known as the population density. It is the number of individuals in an unit area, such as per square kilometre. 

(2) Natality: It is the number of live births per 1000 people of population per year.

(i) Xylem and Water transport. 

(ii) Ciliary body and Accommodation of eye lens

(iii) Seminiferous tubule and Spermatogenesis 

(iv) Thyroid gland and basal Metabolism 

(v) Eustachian tube and Body equilibrium

(i) Nuclear Membrane 

(ii) Vitreous humour 

(iii) Stroma.

(iv) Genes 

(v) Acetylcholine

Water enters the root hair from the soil by the process of Endosmosis. This is because the solution in the soil is hypotonic whereas the cell sap in the root hair cell is hypertonic. The water then passes through the cortical cells by cell to cell osmosis and reaches the xylem of the root.

(i)

(ii)

(iii) 

(iv) 

(v)

(i)

(ii)

(iii)

(iv)

(v)

1- Prostate gland 

2-Cowper's gland

3- Urethra

4- Sperm duct

5- Testis

(ii) 1- Prostate gland-It secretes an alkaline matter which neutralizes the acidity of the urethra.

4- Sperm duct -It carries sperms from epididymis to the urethra.

(iii) Cells of Leydig.

(iv) Testis is located in the scrotal sacs so that they can maintain a low temperature than the body cavity. This trow temperature is necessary for the maturation of sperms.

(v) Semen is the mixture of sperms and secretions of the seminal vesicles, prostate gland and Cowper's gland.

(i) Destarched plant —> washed in water —> a leaf boiled in alcohol —> placed in sunlight —> Iodine added. 

(ii) Interphase —> Prophase —> Metaphase —> Anaphase —> Telophase. 

(iii) Seminiferous tubule —> Epididymis —> Vas deferens —> Urethra —> Penis. 

(iv) Pinna —> auditory canal tympanum —> ear ossicles —> cochlea. 

(v) Soil water Root hair —> Cortex —> Endodermis Xylem.

(i) Anaphase

(ii) 

A - Spindle fibre 

B - Centromere

(iii) Two sister chromatids of each chromosome separate and are drawn apart towards opposite poles.

(iv) Two daughter cells are formed from this type of cell division.

(i) 1—Seminal vesicle 

2—Prostate gland 

3— Urethra 

4— Sperm duct/vas deferens 

5—Testis. 

(ii) Part 1—Its secretion serves as a medium for the transportation of the sperms. 

Part 2—It carry the sperms. 

(iii) Leydig cells or interstitial cells of part 5 produces testosterone. 

(iv) The structure 5 is present outside the body in the scrotal sac because sperms are produced at 2 to 3°C lower than that of body temperature so, when too hot the skin of scrotal sac looses and testes are away from the body and when it is cold the skin contracts and testis are closer to the body for warmth. 

(v) Semen—The mixture of seminal vesicles secretios and sperms produces a milky fluid, which is called semen.

(i) The alpha cells of the pancreas secrete glucagon. 

(ii) Duplicated chromosomes remain attached at a point termed centromere. 

(iii) True. 

(iv) Penicillin obtained from a fungus is an example of an antibiotic. 

(v) Plants that manufacture their own food are termed autotrophs.

(i) Transpiration. 

(ii) ‘Loss of water as water vapour from the aerial parts of the plant is called as transpiration’. 

(iii) Covering the pot with a plastic sheet would prevent the escape of water vapour from the pot.

(iv) Transpiration helps in the ascent of sap by producing a suction force acting from the top of a plant. 

(v) A similar empty plastic sheet with its mouth tied, with no potted plant kept in sunlight will show no drops of water.

(i) Antibiotics: The chemical substances which are produced by a micro¬organism, can stop growth of or kill another micro-organism. e.g., Pencillin. 

(ii) Antiseptics—These are chemical substances which destroy some bacteria and prevent the growth of others. Antiseptics are used locally in contact of body tissues because they are mild and are harmless to the tissues they work upon. Examples of antiseptics—Tincture, benzoic acid, boric acid, hydrogen peroxide, dettol and mercurochrome. 

(iii) Hormones: According to Selye (1948), “Hormones are the physiological organic compounds produced by certain cells for the sole purpose of directing theractivities to distant parts of the same origins.” A hormone is defined as “a chemical messenger secreted by an endocrine gland which reaches its destination by the blood stream and which has the power of influencing the activity of other distant target organs.” 

(iv) Diffusion: It is the process of movement of molecules of a substance (solid, liquid or gas) from the region of their higher concentration to the region of their lower concentration through the concentration gradient. 

Or 

Diffusion may be defined as the process of random movement of molecules of a substance from a region of higher concentration to a region of lower concentration. 

(v) Destarched plant: The plant which has no starch in the leaves and the leaf remains yellowish brown when the leaf is tested for photosynthesis with iodine solution

(i) Hypothalamus and control pituitary function. 

(ii) Suspensory ligaments and to held lens in position. 

(iii) Semi circular canals and balancing the body.

(iv) Mitochondria and release of energy.

(v) Seminiferous tubules and spermatogenesis.

(i) Corpus luteum and secretion of progesterone. 

(ii) Iris of the eye and regulates the amount of light entering the eye. 

(iii) Seminal vesicle and semen. 

(iv) Phloem and photosynthesis. 

(v) Eustachian tube and balancing the air pressure on either side of the eardrum.

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

(ii) Ciliary body and alter the shape of the lens of eye. 

(iii) Seminiferous tubule and production of sperms in testes. 

(iv) Thyroid gland and regulate basal metabolism. 

(v) Eustachean tube and equalize air pressure on either side of the ear drum.

(i) 1-Red blood cells. 

(ii) Diapedesis 

(iii)

(iv) Phagocytosis Process. By this process the WBC engulfs the diseases causing germs that enter the body and thus defend our body.

(i) Salk’s vaccine is given to build up immunity against polio. 

(ii) Phenotype is the observable characteristic which is genetically controlled. 

(iii) Wooden doors swell up in rainy season due to imbibition. 

(iv) The blood vessel that begins and ends in capillaries is the hepatic portal system. 

(v) Plasmolysis is the phenomenon of contraction of the cytoplasm hern cell wall.

(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.

Destarched plant - It is the plant in which starch has been removed from the leaves.

(i) Bleeding

(ii) Pisum sativum

(iii) Vitreous humour

(iv) Oxy-haemoglobin

(v) Acid rain

(1) on a windy day rate of transpiration increases because of the water vapour will not be allowed to accumulate in the vicinity of the leaves and an increase in the vapour pressure gradient through the stomata will lead to increased rate of transpiration.

(2) A foggy day means more moisture in the air, so the rate of transpiration decreises with the rise in vapour pressure in the atmospheric air.

(i) Transpiration 

(ii) It is the lost of water in the form of water vapours from the aerial parts of the plant 

(iii) Weight of test tube A will decrease after the experiment because water will be lost from it through the leaves by transpiration. Weight of test tube B will remain same after the experiment because water will not be lost by transpiration as there is no plant in it and nor by evaporation as oil is spread over it, which will not allow evaporation.

(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.

(1) Because it controls the secretion of the hormones of other endocrine glands.

(2) Because after sexual reproduction, the diploid number of chromosome is maintained.

Optic nerve the structure that carries visual stimuli from retina to the brain.

(i) Transpiration 

(ii) The two cobalt chloride papers are attached, one on the dorsal and the other on the ventral surface of a dorsiventral leaf with the help of glass slide and clips. The set up is left in the open for few hours. 

(iii) To show that more transpiration occurs from the under surface of the leaf. 

(iv) Cobalt chloride paper in the lower surface will turn pink taster because of presence of more stomata present on the under surface. 

(v) 

(1) Sunken stomata, 

(2) Presence of thick cuticle

(3) Fewer stomata.

(i) Destarched Plant: A plant from the leaves of which starch has been removed. This can be done by placing the plant in the dark for 24 to 48 hours. 

(ii) Phenotype: The expressed character whieh Is genetically controlled. 

Example : Tall pea plants (genotype TT or Tt), dwarf pea plant (genotype tt). So this expressed tallness or dwarfness is called as phenotype. 

(iii) Death Rate: This is also called as mortality It is the number of death per 1000 of population per year. 

(iv) Power of Accommodation of the eye: The process of focussing the eye at different distances is called as power of accommodation of the eye. 

(v) Natural Immunity: This is also called as native or innate immunity. This immunity is by virtue of genetic constitutional make up Tt is there in the body without any external stimulation of a previous infection.

Recessive allele

Diffusion - It is the movement of molecules of any type, from their high to their low concentration.

Semi-permeable membrane

Hormones - These are the chemicals produced by ductless glands into the blood and which act on target organs.

(i) Onset of menstruation in a young girl around the age of 13 years ‘Menarche’. 

(ii) Eye defect occurring in old people whereby they are unable to see near objects Presbyopia. 

(iii) The mucous membrane lining the uterus Endometrium 

(iv) The process of conversion of ADP to ATP during the first, phase of photosynthesis Photophosphorylation. 

(v) The point of contact between two neurons ‘Synapse’. 

(vi) Protective membranes covering the human brain and spinal cord ‘Meninges’. 

(vii) Respiratory openings found on the stem of woody plants ‘Lenticels’. 

(viii) Harmful microbes ‘Phagocytosis’. 

(ix) The process of mixing of two different substances/molecules ‘Diffusion’. 

(x) Exudation of sap from injured part of a plant ‘Bleeding’.

(i) Controlling pituitary gland.

(ii) Holding eye lens in position.

(iii) Dynamic balance.

(iv) Cellular respiration.

(v) Spermatogenesis.

Isotonic a solution in which the relative concentration of water molecules and the solute on either side of the cell membrane is the same.

(i) Ethane 

(ii) Sulphur dioxide 

(iii) Nitrogen dioxide 

(iv) Oxygen 

(v) Chlorine

(i)  The two prongs of a tuning fork set each other in resonant vibrations which help to maintain the vibrations for a longer time.

(ii)  While crossing a hanging (or rope) bridge, soldiers are asked to break steps because if they are up in steps, all the separate forces being in the same phase, will produce strong energetic vibrations of a particular frequency. If the natural frequency of the bridge becomes equal to the frequency of the steps, the bridge will vibrate will larger amplitude due to resonance and hence the bridge might overturn or crumble down.

1) Photosynthesis 

2) Transpiration

3) Transportation

Photosynthesis:  Photosynthesis is the process by which plants make energy to grow. Photosynthesis requires sunlight, water and carbon dioxide. We demonstrated what happens when a plant cannot photosynthesise when we made our cress caterpillar.

Transpiration:  Transpiration is the process by which water moves up the stem of a plant from root to leaf when water is lost from the plant due to evaporation occurring at the leaves. This continual flow of water and nutrients  keeps the plant’s cells firm, if the cells become short of water they lose firmness and the plant starts to wilt.

We can demonstrate transpiration by placing white flowers in coloured water, the water travels up the stem to the petals which become coloured like the water.

Transportation: Transportation is a vital process in plants. Trees transport all the nutrients and water it needs for survival from its roots to the tips of the leaves.

In the case of transportation in plants, the biggest constraint is water as it ends up being a limiting factor in growth.  To overcome this problem, trees and other plants have the perfect system for the absorption and translocation of water.

(i) 3rd period, 16th group. 

(ii) Z is a non-metal. 

(iii) H₂Z 

(iv) Covalent compound.

Anode is the oxidising electrode because anions lose electrons at anode.

Anode. Because anode is the oxidising electrode, there is loss of electrons.

1. Ions i.e., Na⁺ and OH^–

2. Ions i.e., H⁺ and CO₃^2– 

3. Molecules C₁₂H₂₂O₁₁

Z = 16 = 2, 8, 6.

1. Period No. = 3

Group No. = VI A/16

2. Non metal. 

3. Z’s valency = – 2

H = +1 So formula H₂Z

4. Polar Covalent compound.

1. Hydronium 

2. Hydroxide 

3. Salt 

4. Water 

5. Hydrogen

1. Electrovalent/Ionic compound is formed.

2. 1 

3. M belong to alkali metal group i.e., Group-1. 

4. M^- + e^– → M — Reduction. 

5. Oxygen gas.

(i) Electrovalent bond exists between M and O. 

(ii) One electron is there in the outermost shell. 

(iii) M belongs to First group. 

(iv) M⁺ + e^- -----> M (at cathode). 

(v) Oxygen gas is liberated at anode.

(i) Hydronium 

(ii) Hydroxide 

(iii) Salt 

(iv) Water 

(v) Hydrogen

We have AP = 9 cm, CQ = 6 cm and AB = 12 cm.

For triangles △BAP & △BCQ,

∠BAP = ∠BCQ = 90°(\(\because\) Angle between radius and tangent at point of contact in 90°)

∠ABP = ∠CBQ (Vertically opposite angles)

∠APB = ∠BQC (sum of angles in a triangle in 180°)

\(\therefore\) △ BAP \(\sim\) △BCQ (By AAA similarity criteria)

\(\therefore\) AP/CQ = AB/BC

⇒ BC = \(\frac{AB\times CQ}{AP}\) = \(\frac{12\times6}9\)

 = 4 x 2 = 8 cm

Now, in △ ABP,

BP² = AP² + AB²

 = 9² + 12²

= 81 + 144

= 225

= 15²

\(\therefore\) BP = 15 cm

Now, in △BCQ,

BQ² = BC² + QC²

 = 8² + 6²

= 64 + 36 = 100 = 10²

\(\therefore\)  BP = 10 cm

Now, PQ = BP + BQ = 15 + 10

= 25 cm