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Select the odd one out (a) The movement of water across a semi-permeable membrane is affected by the amount of substances dissolved in it. (b) Membranes are made of organic molecules like proteins and lipids (c) Molecules soluble in organic solvents can easily pass through the membrane. (d) Plasma membranes contain chitin sugar in plants

d) Plasma membranes contain chitin sugar in plants. Each cell is bounded by an extremely delicate, thin elastic living membrane, called... View Article

Among the given options, which one is not correct for the use of a large amount of fertilisers and pesticides? (a) They are eco-friendly (b) They turn the fields barren after some time (c) They adversely affect the useful component from the soil (d) They destroy the soil fertility

a) They are eco-friendly Explanation Pesticides are chemical substances that are meant to kill pests. In general, a pesticide is a... View Article

Choose the correct statement of the following (a) Conversion of solid into vapours without passing through the liquid state is called sublimation. (b) Conversion of vapours into solid without passing through the liquid state is called vaporisation. (c) Conversion of vapours into solid without passing through the liquid state is called freezing. (d) Conversion of solid into liquid is called sublimation.

b) Conversion of solid into vapours without passing through the liquid state is called sublimation. Conversion of solid into vapours... View Article

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... 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 Explanation The visibility of forming fog is lowered during winter is... 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 Explanation Animals that possess a backbone is classified as a vertebrate. There are numerous vertebrates currently... 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... 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.... 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... 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... 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 Explanation Tendrils are hair-like or very thin... 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... 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... 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... 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... 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 Explanation The respiratory route of air in the respiratory tract is: Nostrils → nasal... 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... 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. Explanation Making anti-viral medicines is difficult than making anti-bacterial drugs... 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,... View Article

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