How do carbohydrates,
Question: How do carbohydrates, proteins and fats get digested in human beings ? Solution: Carbohydrates: Glucose. Proteins: Amino acids. Fats: Fatty acids and glycerol. Carbohydrates: In mouth cavity (by saliva), duodenum (by pancreatic juice) and jejunum (by intestinal juice). Proteins: In stomach (by gastric juice), duodenum (by pancreatic juice) and jejunum (by intestinal juice). Fats: In duodenum and jejunum (by pancreatic juice aided by bile salts). Also in infants in stomach....
Read More →A dealer bought a refrigerator for Rs 11515.
Question: A dealer bought a refrigerator for Rs 11515. After allowing a discount of 16% on its marked price, he gains 20%. Find the marked price of the refrigerator. Solution: Cost price of the refrigerator $=R s 11515$ Gain percentage $=20 \%$. $\therefore$ Selling price $=\left\{\frac{(100+\text { gain } \%)}{100} \times C . P\right\}$ $=\left\{\frac{100+20}{100} \times 11515\right\}$ $=\frac{120}{100} \times 11515$ $=$ Rs 13818 Let the marked price be Rs $x$. Discount $=16 \%$ of $B$ s $x$ $=...
Read More →Explain the process of breathing in man.
Question: Explain the process of breathing in man. Solution: Breathing or the process of taking in fresh air and releasing foul air can be easily observed because thorax shows alternate expansion and contraction. It is involuntary though it can be prevented for a brief period. Rate of breathing is controlled by respiratory centre of brain. Expansion of thorax causes fresh air to be drawn in. Contraction of thorax causes foul air to be expelled. Therefore, breathing consists of two steps, inspira...
Read More →A dealer purchased a fan for Rs 1080.
Question: A dealer purchased a fan for Rs 1080. After allowing a discount of 25% on its marked price, he gains 25%. Find the marked price of the fan. Solution: Cost price of the fan $=R s 1080$ Gain percentage $=25 \%$ $\therefore$ Selling price $=\left\{\frac{(100+\text { gain } \%)}{100} \times \mathrm{CP}\right\}$ $=\left\{\frac{100+25}{100} \times 1080\right\}$ $=\frac{125}{100} \times 1080$ $=$ Rs 1350 Let the marked price be Rs $x$. Discount $=25 \%$ of $R s x$ $=\frac{25 x}{100}$ SP = MP ...
Read More →Describe the alimentary canal of man.
Question: Describe the alimentary canal of man. Solution: Alimentary canal (L. alere-to nourish) is a tubular passage extending from mouth to anus through which food passes during its digestion and absorption. It is about 9 metres in length. Alimentary canal consists of mouth, buccal cavity, oesophagus, stomach, small intestine, large intestine and anus. Mouth:It is a transverse slit like aperture that occurs in between the nose and the chin. Mouth is bounded by two soft, movable sensitive lips,...
Read More →A cellphone was marked at 40% above the cost price and a discount of 30% was given on its marked price.
Question: A cellphone was marked at 40% above the cost price and a discount of 30% was given on its marked price. Find the gain or loss per cent made by the shopkeeper. Solution: Let Rs 100 be the CP. Then, marked price $=R s 140$ Discount $=30 \%$ of MP $=\frac{30}{100} \times 140$ $=42$ Selling Price = marked price discount = 140 42 = Rs 98 Now, loss = CP SP = 100 98 = Rs 2 $\therefore$ Loss percentage $=\frac{\text { Loss } \times 100}{C P}$ $=\frac{2 \times 100}{100}$ $=2 \%$ Therefore, the ...
Read More →Explain the process of nutrition in Amoeba.
Question: Explain the process of nutrition in Amoeba. Solution: 1. Ingestion:(L. ingestus taken in). It is taking in of solid food with the help of temporary or permanent mouth. Amoeba can ingest food particles from any point on its surface. Paramoecium (another unicellular organism) has fixed point for the same. Amoeba captures food with the help of temporary finger-like processes called pseudopodia. Paramoecium has small hair-like processes called cilia. Beating of cilia creates current in wat...
Read More →Differentiate the following functions with respect to x :
Question: Differentiate the following functions with respect to $x$ : $x^{\cos ^{-1} x}$ Solution: Let $y=x^{\cos ^{-1} x}$ Taking log both the sides: $\Rightarrow \log y=\log x^{\cos ^{-1} x}$ $\Rightarrow \log y=\cos ^{-1} x \log x\left\{\log x^{a}=\operatorname{alog} x\right\}$ Differentiating with respect to $\mathrm{x}$ : $\Rightarrow \frac{\mathrm{d}(\log \mathrm{y})}{\mathrm{dx}}=\frac{\mathrm{d}\left(\cos ^{-1} \mathrm{x} \log \mathrm{x}\right)}{\mathrm{dx}}$ $\Rightarrow \frac{\mathrm{d...
Read More →A dealer marks his goods at 35% above the cost price and allows a discount of 20% on the marked price.
Question: A dealer marks his goods at 35% above the cost price and allows a discount of 20% on the marked price. Find the gain or loss per cent. Solution: Let Rs 100 be the CP. Then, marked price $=R s 135$ Discount $=20 \%$ of $\mathrm{MP}$ $=\frac{20}{100} \times 135$ $=27$ Selling price = marked price discount = 135 27 = Rs 108 Now, gain = SP CP =108 100 =Rs 8 $\therefore$ Gain percentage $=\frac{\text { gain }}{\mathrm{CP}} \times 100$ $=\frac{8}{100} \times 100$ $=8 \%$...
Read More →How does leaves of plants help
Question: How does leaves of plants help in excretion ? (CCE 2016) Solution: Waste materials produced in plant cells are stored in their vacuoles. In leaves, the waste materials are Stored in vacuoles of mesophyll and epidermal cells, Oxalic acid is crystallised as calcium oxalate. Nitrogenous wastes are changed into alkaloids Vaste aromatic compounds are changed into tannins. As the old leaves fall, the waste materials are also removed from the plant....
Read More →Why is transpiration important for plants ?
Question: Why is transpiration important for plants ? Solution: Importance Cooling: Evaporation of water from the aerial parts results in lowering of their temperature which will otherwise rise due to exposure to sun. Concentration of Minerals: Transpiration helps in increasing concentration of minerals present in rising water. Transport: It creates a pull that helps in transport of water and minerals....
Read More →Differentiate the following functions with respect to x :
Question: Differentiate the following functions with respect to $x$ : $(1+\cos x)^{x}$ Solution: Let $y=(1+\cos x)^{x}$ Taking log both the sides: $\Rightarrow \log y=\log (1+\cos x)^{x}$ $\Rightarrow \log y=x \log (1+\cos x)\left\{\log x^{a}=\operatorname{alog} x\right\}$ Differentiating with respect to $\mathrm{x}$ : $\Rightarrow \frac{\mathrm{d}(\log \mathrm{y})}{\mathrm{dx}}=\frac{\mathrm{d}[\mathrm{x} \log (1+\cos \mathrm{x})]}{\mathrm{dx}}$ $\Rightarrow \frac{d(\log y)}{d x}=x \times \frac...
Read More →A tea set was bought for Rs 528 after getting a discount of 12% on its marked price.
Question: A tea set was bought for Rs 528 after getting a discount of 12% on its marked price. Find the marked price of the tea set. Solution: Cost price = Rs 528 Rate of discount = $12 \%$ Marked price =? $\mathrm{SP}=\mathrm{MP}$ - discount Let the MP be Rs $x$. Now, $\frac{x-12}{100 \times x}=528$ $\Rightarrow \frac{88 x}{100}=528$ $\Rightarrow 88 x=52800$ $\Rightarrow x=\frac{52800}{88}$ $\Rightarrow x=$ Rs 600 Therefore, the marked price of tea set is Rs 600 ....
Read More →Why and how does water enter continuously
Question: Why and how does water enter continuously into root xylem ? Solution: Root cells in the absorbing part of root pick up ions actively from soil. Ions pass inwardly increasing osmotic concentration of xylem. Because of it soil water (which has very low osmotic concentration) continuously passes into root xylem....
Read More →After allowing a discount of 8% on a toy, it is sold for Rs 216.20.
Question: After allowing a discount of 8% on a toy, it is sold for Rs 216.20. Find the marked price of the toy. Solution: Selling Price $=$ Rs $216.20$ Rate of discount $=8 \%$ Marked Price =? SP $=\mathrm{MP}-$ discount Let the MP be Rs $x$. Now, $x-\frac{8}{100} \times x=216.20$ $\Rightarrow \frac{92 x}{100}=216.20$ $\Rightarrow 92 x=21620$ $\Rightarrow x=\frac{21620}{92}$ $\Rightarrow x=235$ $\therefore$ Marked price $=R s 235$...
Read More →Plants have low energy needs as compared
Question: Plants have low energy needs as compared to animals. Explain. Solution: Plants are anchored. They do not move about. Most of their body is made of dead cells and cell walls. Therefore, their requirement for energy is quite low as compared to animals which move about fast in search of food, mate and shelter....
Read More →What will happen if platelets
Question: What will happen if platelets were absent in the blood ? Solution: Blood platelets are a source of thromboplastin which is essential for blood clotting at the place of injury. In the absence of blood platelets, blood clotting will be litde resulting in greater loss of blood from the place of injury....
Read More →Find the rate of discount being given on a shirt whose selling price is ₹ 1092
Question: Find the rate of discount being given on a shirt whose selling price is ₹ 1092 after deducting a discount of ₹ 208 on its marked price. Solution: SP of the shirt $=₹ 1,092$ Discount $=₹ 208$ MP $=$ SP $+$ Discount $=₹ 1,092+₹ 208=₹ 1,300$ $\therefore$ Rate of discount $=\frac{\text { Discount }}{\text { MP }} \times 100 \%=\frac{208}{1300} \times 100 \%=16 \%$...
Read More →Why do veins have thin walls
Question: Why do veins have thin walls as compared to arteries ? Solution: In arteries, blood flows under pressure so that their walls are thick and elastic. In veins the blood is Therefore, their walls are thin. Rather, they possess semilunar valves to check back flow of blood....
Read More →Differentiate the following functions with respect to x :
Question: Differentiate the following functions with respect to $x$ : $x^{\sin x}$ Solution: Let $y=x^{\sin x}$ Taking log both the sides: $\log y=\log \left(x^{\sin x}\right)$ $\log y=\sin x \log x\left\{\log x^{a}=\operatorname{alog} x\right\}$ Differentiating with respect to $\mathrm{x}$ : $\Rightarrow \frac{\mathrm{d}(\log \mathrm{y})}{\mathrm{dx}}=\frac{\mathrm{d}(\sin \mathrm{x} \log \mathrm{x})}{\mathrm{dx}}$ $\Rightarrow \frac{\mathrm{d}(\log \mathrm{y})}{\mathrm{dx}}=\sin \mathrm{x} \ti...
Read More →The price of a sweater was slashed from Rs 960 to Rs 816 by a shopkeeper in the winter season.
Question: The price of a sweater was slashed from Rs 960 to Rs 816 by a shopkeeper in the winter season. Find the rate of discount given by him. Solution: Marked Price = Rs 960 Selling Price = Rs 816 Discount = MP SP Rate of discount $=144 \times \frac{100}{960}=15 \%$ Therefore, the discount on the sweater is 15%. = Rs (960 816) = Rs 144...
Read More →Name the correct substrates
Question: Name the correct substrates for the following enzymes : (a) Trypsin (b) Amylase (c) Pepsin (d) Lipase. Solution: (a) Trypsin: Proteins, peptones and proteoses, (b) Amylase: Starch, dextrins. (c) Pepsin: Proteins. (d) Lipase: Fats....
Read More →Match the items of columns A and B
Question: Match the items of columns A and B Solution: a i, b iv, c ii, d iii....
Read More →The marked price of a water cooler is Rs 4650.
Question: The marked price of a water cooler is Rs 4650. The shopkeeper offers an off-season discount of 18% on it. Find its selling price. Solution: Marked price $=$ Rs 4650 and discount $=18 \%$ Discount $=18 \%$ of marked price $=18 \%$ of $R s 4650$ $=R s\left(4650 \times \frac{18}{100}\right)$ $=R s 837$ Selling price $=$ marked price $-$ discount $=$ Rs $(4650-837)$ $=$ Rs 3813 Therefore, the selling price of the cooler is Rs 3813 ....
Read More →What are the functions of gastric
Question: What are the functions of gastric glands present in the wall of stomach ? (CCE 2011) Solution: Gastric glands produce the following substances : Mucus: Moistening the food and protecting the wall of the stomach from corroding action of HCl and pepsin. HCl: It makes the food soft, sterilised and acidified for pepsin to act upon food. Gastric Lipase: It is active only in infants. It partially breaks down fat into its components. Rennin: It is active in infants where it helps in curdling ...
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