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During adolescence, the body of boys and girls undergoes certain changes. Given below are a few of those changes. (a) Broad shoulders (b) Wider chests (c) The wider region below the waist (d) Development of muscles (e) Development of mammary glands (f) Growth of facial hair (g) Acne and pimples on the face (h) Development of sex organs (i) High-pitched voice (j) Growth of pubic hair. Categorise these changes according to their occurrence in boys and those that occur in girls and fill in the table given below.

Boys Girls Broad Shoulders Wider region below waist Wilder Chest Development of mammary glands Growth of muscles Acne and pimples on... View Article

Low visibility during cold weather is due to (a) formation of fossil fuel (b) unburnt carbon particles or hydrocarbons suspended in air (c) lack of adequate power supply (d) none of these

b) unburnt carbon particles or hydrocarbons suspended in air The visibility of forming fog is lowered during winter is due to the water... View Article

Which one is the most striking or (common) character of the vertebrates? (a) Presence of notochord (b) Presence of triploblastic condition (c) Presence of gill pouches (d) Presence of coelom

(a) Presence of notochord Animals that possess a backbone is classified as a vertebrate. There are numerous vertebrates currently existing on... View Article

Which statement is incorrect about endangered species? (a) Their number has decreased drastically. (b) They might become extinct in the near future. (c) They pose a danger to other animals. (d) Their natural habitat needs to be protected

a) Their number has decreased drastically. An Endangered (EN) species is a species which has been categorized by the International Union for... View Article

Match the following A and B (A) – (B) (a) Cattle used for tilling and carting – (i) Milk producing female (b) Indian breed of chicken – (ii) Broiler (c) Sahiwal, Red Sindhi – (iii) Drought animals (d) Milch – (iv) Local breed of cattle (e) Chicken better fed for obtaining – (v) Aseel

Column I Column II A. Cattle used for tlling and carting Drought animals B. Indian breed of chicken Aseel C. Sahiwal, red sindhi Local... View Article

In each of the following situations what happens to the rate of photosynthesis? (a) Cloudy days (b) No rainfall in the area (c) Good manuring in the area (d) Stomata get blocked due to dust

The photosynthesis process occurs in plants. It takes place in chloroplasts at the cellular level that contains the chlorophyll. Leaves have... View Article

The calorific values of petrol and CNG are 45000 kJ/kg and 50,000 kJ/kg, respectively. If you have a vehicle which can run on petrol as well as CNG, which fuel will you prefer and why?

We will prefer CNG to run the vehicle. This is because the calorific value of CNG is higher than that of petrol. Therefore, CNG will be more... View Article

Some natural resources are given in a box. Classify them into the exhaustible and inexhaustible natural resources. Air, Coal, Natural gas, Sunlight, Petroleum, Minerals, Forests and Oxygen.

Exhaustible resources are coal, natural gas, petroleum, minerals, forests. They are present in limited quantity and are exhausted by human... View Article

The growth of tendril in pea plants is due to (a) effect of light (b) effect of gravity (c) rapid cell divisions in tendrillar cells that are away from the support (d) rapid cell divisions in tendrillar cells in contact with the support

c) Rapid cell divisions in tendril cells that are away from the support Tendrils are hair-like or very thin thread-like growths of some plants... View Article

Name the following (a) The process in plants that links light energy with chemical energy (b) Organisms that can prepare their own food (c) The cell organelle where photosynthesis occurs (d) Cells that surround a stomatal pore (e) Organisms that cannot prepare their own food (f) An enzyme secreted from gastric glands in the stomach that acts on proteins.

(i) Photosynthesis: It is a process by which green plants having chlorophyll synthesise simple sugar (glucose) from water and CO2 using the... View Article

Seema visited a Natural Gas Compressing Unit and found that the gas can be liquefied under specific conditions of temperature and pressure. While sharing her experience with friends she got confused. Help her to identify the correct set of conditions (a) Low temperature, low pressure (b) High temperature, low pressure (c) Low temperature, high pressure (d) High temperature, high pressure

(c) Low temperature and high pressure are required to liquefy gases to liquids. There is a lot of space between the particles of a gas. On... View Article

Classify the following into osmosis/diffusion (a) Swelling up of a raisin on keeping in water. (b) Spreading of virus on sneezing. (c) Earthworm dying on coming in contact with common salt. (d) Shrinking of grapes kept in thick sugar syrup. (e) Preserving pickles in salt. (f) Spreading of smell of cake being baked throughout the house. (g) Aquatic animals using oxygen dissolved in water during respiration

(a) The swelling up of a raisin on keeping in water is Osmosis The concentration of solutes in raisin is more than outside water. Hence, water... View Article

On placing an inverted tumbler over a burning candle, the flame extinguishes after some time. This is because of the nonavailability of (a) oxygen (b) water vapours (c) carbon dioxide (d) wax

(a) oxygen On placing an inverted tumbler over a burning candle, the flame extinguishes after some time. This is because of the non-availability... View Article

Which is the correct sequence of air passage during inhalation? (a) Nostrils →larynx →pharynx →trachea →lungs (b) Nasal passage →trachea →pharynx →larynx →alveoli (c) larynx →nostrils →pharynx →lungs (d) Nostrils →pharynx →larynx →trachea →alveoli

(d) Nostrils →pharynx →larynx →trachea →alveoli The respiratory route of air in the respiratory tract is: Nostrils →... View Article

In Fig. mark the positions of the endocrine glands which release the hormones that: (a) controls the release of sex hormones. (b) is responsible for the secondary sexual characters in boys. (c) prevents diabetes. (d) maintains the correct salt balance in the blood.

a) The pituitary gland is the master gland which controls the secretion of all other endocrine glands so it also controls the secretion of sex... View Article

Making anti-viral drugs is more difficult than making anti-bacterial medicines because (a) viruses make use of host machinery (b) viruses are on the border line of living and non-living (c) viruses have very few biochemical mechanisms of their own (d) viruses have a protein coat

c) Viruses have very few biochemical mechanisms of their own. Making anti-viral medicines is difficult than making anti-bacterial drugs because... View Article

In the following statements, the underlined words are jumbled up. Write them in their correct form. (a) Air contains 78% ginroten and 21% gonexy. (b) Vehicles produce high level of pollutants like carbon dioxide, nitrogen oxides, nobrac moondexi and mosek. (c) Carbon dioxide, thaneme, nitrous oxide and water vapour are known as heengrouse sesga. (d) Gangotri glacier in Himalaya has started melting because of lablog ringwam. (e) Whenever harmful substances such as wagese, toxic chemicals, silt, etc. get mixed with water, the water becomes potdulle.

(a) Air contains 78% nitrogen and 21% oxygen. (b) Vehicles produce high level of pollutants like carbon dioxide, nitrogen oxides, carbon monoxide... View Article

Under a microscope Paheli observes a cell that has a cell wall but no distinct nucleus. The cell that she observes is (a) a plant cell (b) an animal cell (c) a nerve cell (d) a bacterial cell

(d)A bacterial cell The cell observed by Paheli is a bacterial cell. It is a prokaryotic cell that has a cell wall (like plants) but no distinct... View Article

A lady went to the market to buy a blanket. The shopkeeper showed her blankets made of acrylic fibres as well as made of wool. She preferred to buy an acrylic blanket. Can you guess why?

Acrylic blankets are cheap, light in weight, more durable and are available in a variety of colours and designs. They can be easily washed at... View Article

Which condition out of the following will increase the evaporation of water? (a) Increase in temperature of water (b) Decrease in temperature of water (c) Less exposed surface area of water (d) Adding common salt to water

a) Increase in temperature of water In evaporation when the temperature is increased, the molecules gain kinetic energy and molecules start... View Article

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