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Design an activity to show that chlorophyll is essential for photosynthesis.
 

To show that chlorophyll is necessary for photosynthesis
 

Procedure
1.Take a plant with variegated leaves which has chlorophyll only in patches. Such leaves can be found in plants like Colcus, Tradescantia, and Croton.
2. Destarch its leaves by placing the plant in dark for 2-3 days

3. Place the plant again in daylight for about 4-6 hours. Test a leaf for the presence of starch.
Observation

Only the parts which were green previously, turn bloc-black with iodine.
Conclusion
This shows that chlorophyll is necessary for photosynthesis.

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(a) Two lamps rated 100\; W,\; 220\; V and 10\; W,\; 220\; V are connected in parallel to 220\; V supply. Calculate the total current through the circuit. (b) Two resistors X and Y of resistances 2\; \Omega and 3\; \Omega respectively are first joined in parallel and then in series. In each case the voltage supplied is 5\; V. (i) Draw circuit diagrams to show the combination of resistors in each case. (ii) Calculate the voltage across the 3\; \Omega resistor in the series combination of resistors.
 

(a)   I1 = P1/V

I1 = 100 W/ 220 V = 10/  22 A

I2 = P2 / V = 10/ 220 = 1/ 22 A

I = I1 + I2 = = 0.5 A

(b)

(i) Circuit diagrams to show the combination of resistors in each case- 

(ii) Net R=R1+R2=2+3=5 ?

I = V/ Rnet = 5 / 5 = 1A

∴ Voltage across 3? resistor - 

∴ V = 1 × 3 = 3V

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Give reasons : (a) Ventricles have thicker muscular walls than atria. (b) Transport system in plants is slow. (c) Circulation of blood in aquatic vertebrates differs from that in terrestrial vertebrates. (d) During the daytime, water and minerals travel faster through xylem as compared to the night. (e) Veins have valves whereas arteries do not.
 

a) because ventricles have to pump blood out of the heart.

b) because plants are not motile and have a large proportion of dead cells in many tissues and due to which their energy needs are low and have a slow transport system.

c) because the terrestrial vertebrates take oxygen from the air through their lungs and the aquatic invertebrates take oxygen from the water through their gills.

d) because the rate of transpiration is higher during the daytime as compared to night.

e) because arteries don't require valves, as the pressure from the heart is so strong that blood is only able to flow in one direction.

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In the question two statements are given one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (i), (ii), (iii) and (iv) as given below. Assertion (A) : At high temperatures, metal wires have a greater chance of short circuiting. Reason (R) : Both resistance and resistivity of a material vary with temperature.  
Option: 1 Both (A) and (R) are true and (R) is correct explanation of the assertion (A).
Option: 2 Both (A) and (R) are true, but (R) is not the correct explanation of the assertion (A).
Option: 3 (A) is true, but (R) is false.
Option: 4 (A) is false, but (R) is true.

Both (A) and (R) are true, but (R) is not the correct explanation of the assertion (A).

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In the question two statements are given one labelled Assertion (A) and the other labelled Reason (R). Select the correct
answer to these questions from the codes (i), (ii), (iii) and (iv) as given below. Assertion (A) : Carbon has a strong tendency to either lose or gain electrons to attain noble gas configuration. Reason (R) : Carbon has four electrons in its outermost shell and has the tendency to share electrons with carbon or other                       elements.
Option: 1 Both (A) and (R) are true and (R) is correct explanation of the assertion (A).
Option: 2 Both (A) and (R) are true, but (R) is not the correct explanation of the assertion (A).
Option: 3 (A) is true, but (R) is false.
Option: 4 (A) is false, but (R) is true.

(A) is false, but (R) is true.

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An element X is forming acidic oxide. Its most probable position in the modern periodic table is
Option: 1 Group 1 and Period 3
Option: 2 Group 16 and Period 3
Option: 3 Group 17 and Period 3
Option: 4 Group 2 and Period 3

Group 16 and Period 3

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An element X with atomic number 12 forms a compound with element Y with atomic number 17. The formula of the compound formed is
Option: 1 XY  
Option: 2 XY_{2}
Option: 3 X_{2}Y
Option: 4 X_{2}Y_{3}

The formula of the compound formed is XY_{2}

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If 10\; mL of H_{2}SO_{4} is mixed with 10\; mL  of Mg(OH)_{2} of the same concentration, the resultant solution will give the following colour with universal indicator :
Option: 1 Red
Option: 2 Yellow
Option: 3 Green
Option: 4 Blue

Green

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Strong heating of ferrous sulphate leads to the formation of a brown solid and two gases. This reaction can be categorised as
Option: 1 displacement and redox.
Option: 2 decomposition and redox.
Option: 3 displacement and endothermic.
Option: 4 decomposition and exothermic.

This reaction can be categorised as decomposition and redox.

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The Reni village of Garhwal is famous for
Option: 1 Monocultures of pine, teak and eucalyptus.
Option: 2 Chipko Movement.
Option: 3 Extensive biodiversity.
Option: 4 Participation of local people in efficient management of forests.

The Reni village of Garhwal is famous for Chipko Movement.

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