Question

answer the following question

Answer 1

ans-12 Chromosomes are thread-like structures located inside the nucleus of animal and plant cells.
 Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA). Passed from parents to offspring, DNA contains the specific instructions that make each type of living creature unique.
 Chromatin condensation changes during the cell cycle. During interphase (1), chromatin is in its least condensed state and appears loosely distributed throughout the nucleus. Chromatincondensation begins during prophase (2) and chromosomes become visible.

ans-13 Odometer is a device that measures the distance travelled by anautomobile based on the perimeter of the wheel as the wheel rotates.
CASE A:
speed=300m/min.
Case B:
SPEED is 36km/hr=36x1000m/60 min=600m/min
by comparing we can say that Car moves faster than scotter because it covers a distance of 600m in 1 min.

ans-14 Given:Let T be the time taken for the entire journey.Total DISTANCE = 100mAverage speed for entire journey =40km/ hAs we know:Average speed= TOTAL DISTANCE/ TOTAL timeTotal time =100/40=10/4 hours
Time taken to cover first part of journey be t1.Distance covered is 30km .Average speed to cover 30km is 30km/ hTime taken to cover part of journey: t1t1= 30km/ 30km/ h=1 hrTime taken to cover second part of journey be t2Distance covered is 70kmLet x be the average speed for covering 70kmTime t2=70/XTotal time= T=t1 + t2=1+70/xTotal time is 10/ 4 hrsSo,10/4 =70/x + 110/4=(70+ x)/x5/2=(70+x)/x5x =2 (70+x)5x=140+2x5x-2x=1403x=140X=140/3=46.66km/ hTherefore Train must travel at a average speed of 46.66 km/ h to cover 70km.
ans 15  a) Boiling point of water at STP is 100 degrees Celsius .As altitude increases, Boiling point of water decreases than its normal Boiling point . So, water boils at low temperature and evaporates.SO, IF YOU COOk FOOD in open vessels takes longer time for cooking.
b) Principle working of pressure cooker:Boiling point of water increases with increase in pressure.Hence in pressure cooker if we cook food , it takes less time .
C) Advantages of using pressure cooker:1. Reduces time of cooking.2. Fuel consumption is reduced.3. Cooks tasty food.4. Retains all the nutrients in food while cooking.

Answer 2

Answer:

Explanation:

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