CBSE Class 10 Answered

23. Breakdown of glucose:

24. Our elders recommend not to sleep under a tree at night because the rate of respiration in plants is higher during the night. Hence, a large amount of carbon dioxide is produced. Plants also respire during the day but the CO2 produced is utilized in the process of photosynthesis. However, at night, in the absence of sunlight, there is o photosynthesis. It is possible that we may inhale this excess of CO₂ which may not be good for the body. If we sleep under a tree at night we may not get sufficient oxygen during breathing thus making it hard to breathe. Also, we may get protection from the droppings of perching birds, night-active insects, snakes, and spiders.

25. The rate of breathing in aquatic organisms is much faster than that in terrestrial organisms because the amount of dissolved oxygen in water is fairly low compared to the amount of oxygen in the air.