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The boiling points of diethyl ether, acetone and n-butyl alcohol are 35°C, 56°C and 118°C respectively. Which one of the following correctly represents their boiling points in kelvin scale? (a) 306 K, 329 K, 391 K (b) 308 K, 329 K, 392 K (c) 308 K, 329 K, 391 K (d) 329 K, 392 K, 308 K

c) 308 K, 329 K, 391 K Kelvin temperature is 0 degree Celsius + 273. The boiling points of diethyl ether, acetone and n-butyl alcohol are... View Article

When we breathe in air, nitrogen also goes inside along with oxygen. What is the fate of nitrogen? (a) It moves along with oxygen into the cells (b) It comes out with the CO2 during exhalation (c) It is absorbed only by the nasal cells (d) Nitrogen concentration is already more in the cells so it is not at all absorbed.

b) It comes out with the CO2 during exhalation. Breathing is nothing but the muscular movements that can be divided into inspiration (intake of... View Article

Find out the correct sentence (a) Enzymes packed in lysosomes are made through RER (rough endoplasmic reticulum) (b) Rough endoplasmic reticulum and smooth endoplasmic reticulum produce lipid and protein respectively (c) Endoplasmic reticulum is related to the destruction of plasma membrane (d) Nucleoid is present inside the nucleoplasm of eukaryotic nucleus

a) Enzymes packed in lysosomes are made through RER (rough endoplasmic reticulum). Rough endoplasmic reticulum produce proteins and smooth RER... View Article

Lila always eats only dal and rice in every meal. She often falls ill and has become prone to diseases. Can you suggest changes in her diet which can make her healthy and free from disease?

Lila always eats dal and rice but not any other vegetables or fruits that mean she is not taking a balanced diet. Fruits and vegetables consists... View Article

Wild buffalo is an endangered species because (a) its population is diminishing (b) it has become extinct (c) it is found exclusively in a particular area (d) its poaching is strictly prohibited

(a)its population is diminishing Endangered species can be defined as those species which are under risk or threat of being extinct. In other... View Article

Paheli accidentally placed her hand over a flame and immediately pulled it back. She felt the sensation of heat and reacted due to the action of (a) blood cells (b) skin surface (c) nerve cells (d) nucleus of cells

(c) nerve cells Paheli accidentally placed her hand over a flame and immediately pulled it back. She felt the sensation of heat and reacted due... View Article

Which is the correct sequence of parts in the human alimentary canal? (a) Mouth → stomach → small intestine → oesophagus → large intestine (b) Mouth →oesophagus → stomach → large intestine → small intestine (c) Mouth → stomach → oesophagus → small intestine → large intestine (d) Mouth → oesophagus → stomach → small intestine → large intestine

d) Mouth → Oesophagus → Stomach → Small intestine → Large intestine The different organs of the alimentary canal can be... View Article

Unscramble the jumbled words underlined in the following statements. (a) Cells of our body produce santiidobe to fight pathogens. (b) curbossulite is an air-borne disease caused by a bacterium. (c) Xanrhat is a dangerous bacterial disease. (d) Yeasts are used in the wine industry because of their property of meronettinaf.

(a) Cells of our body produce antibodies to fight pathogens. An antibody is a protein produced by the body's immune system when it detects... View Article

Find out the correct sentence about manure (i) Manure contains large quantities of organic matter and small quantities of nutrients. (ii) It increases the water holding capacity of sandy soil. (iii) It helps in draining out of excess of water from clayey soil. (iv) Its excessive use pollutes environment because it is made of animal excretory waste. (a) (i) and (iii) (b) (i) and (ii) (c) (ii) and (iii) (d) (iii) and (iv)

b) (i) and (ii) Manure is an organic matter derived from the solid animal wastes, used to improve the soil quality and increase the yield of... View Article

Some of the following statements are incorrect. Find the incorrect statements and correct them. (a) The property of metals by virtue of which they can be drawn into wires is called ductility. (b) Metals are good conductor of electricity but poor conductor of heat. (c) Articles made of metals produce ringing sound when struck hard. (d) Oxides of non-metals and metals are acidic in nature. (e) A less reactive metal replaces a more reactive metal from its salt solution in water.

Statements 2, 4, and 5 are not correct. 2. Metals are good conductors of electricity and also good conductors of heat. Metals are an... View Article

Vectors can be defined as (a) animals carrying the infecting agents from sick person to another healthy person (b) microorganisms which cause many diseases (c) infected person (d) diseased plants

a)Animals that carry the infecting agents from an infected individual to another healthy individual. Vector Borne diseases are the illness... View Article

Plasmolysis in a plant cell is defined as (a) break down (lysis ) of plasma membrane in hypotonic medium (b) shrinkage of cytoplasm in hypertonic medium (c) shrinkage of nucleoplasm (d) none of them

B) Shrinkage of cytoplasm in hypertonic medium When a plant cell is kept in a hypertonic medium, the water inside the cell moves outside due to... View Article

Boojho has learnt that non-metals on beating with a hammer are generally broken into pieces. Which of the following is a nonmetal? (a) Iron nail (b) Aluminium wire (c) Copperplate (d) Piece of coal

(d) Piece of coal In the given options iron, aluminium and copper, all are metals, but only carbon is a non-metal which is breakable with a... View Article

Read the different combinations of terms given below: (a) cell wall, cell membrane, nucleus, plastid (b) cell wall, nucleus, ribosome, chromosome (c) the cell membrane, mitochondria, ribosome, chromosome (d) the cell membrane, ribosome, mitochondria, chloroplast. The correct combination of terms with reference to an animal cell is _____.

c) Cell membrane, Ribosome, Mitochondria, Chromosome The correct combination of terms with reference to an animal cell is cell membrane,... View Article

On converting 25°C, 38°C and 66°C to kelvin scale, the correct sequence of temperature will be (a) 298 K, 311 K and 339 K (b) 298 K, 300 K and 338 K (c) 273 K, 278 K and 543 K (d) 298 K, 310 K and 338 K

(a) Therefore, the correct sequence of temperature will be 298 K, 311 K and 339 K. On converting 25 °C, 38 °C and 66 °C, to kelvin... View Article

Which of the following is not true for fertilisers? (a) They increase the yield. (b) Their excessive use disturbs the balance of nutrients in the soil. (c) They are generally used in small quantity. (d) They are environment-friendly.

They are environment friendly. Fertilizers are chemical substances supplied to the crops to increase their productivity. These are used by the... View Article

A pond contains clean water. Which of the following activities will produce the least pollution of water? (a) washing clothes in the pond (b) animals bathing in the pond (c) washing motor vehicles in the pond (d) swimming in the pond.

d) Swimming in the pond Swimming in the pond will produce the least pollution of water because no harmful pollutants or any chemicals would be... View Article

If salivary amylase is lacking in the saliva, which of the following events in the mouth cavity will be affected? (a) Proteins breaking down into amino acids (b) Starch breaking down into sugars (c) Fats breaking down into fatty acids and glycerol (d) Absorption of vitamins

b) Starch breaking down into sugars Amylase is the enzyme that catalyses the hydrolysis of starch into simple sugars. So if salivary amylase is... View Article

Find out the false statement (a) Aves are warm-blooded, egg laying and have a four-chambered heart (b) Aves have feather-covered body, forelimbs are modified into wings and breathe through lungs (c) Most of the mammals are viviparous (d) Fishes, amphibians and reptiles are oviparous

d) Fishes, amphibians and reptiles are oviparous. There are a few fishes, amphibians and reptiles which are viviparous. Sharks, stingrays,... View Article

Which of the following statements is correct about receptors? (a) Gustatory receptors detect taste while olfactory receptors detect smell (b) Both gustatory and olfactory receptors detect smell (c) Auditory receptors detect smell and olfactory receptors detect taste (d) Olfactory receptors detect taste and gustatory receptors smell

a) Gustatory receptors detect taste while olfactory receptors detect smell Gustatory receptors are present in the taste buds present over the... View Article

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