Fill in the blanks1. …………………… are the only part of the human body which floats on water 2. …………………… is the gas produced in photosynthesis. 3. Percentage of carbon dioxide in the inhaled air is …………………… . 4. Percentage of oxygen in the inhaled air is …………………… . 5. Percentage of carbon dioxide in the exhaled air is …………………… . 6. Percentage of oxygen in the exhaled air is …………………… . 7. Lime water turns milky white when it reacts with …………………… . 8. Glucose + Oxygen → …………………… + water + Energy 9. Tobacco smoke contains a highly dangerous substance called 10. …………………… respiration is present in insects. 11. Breathing through the skin is called …………………… respiration. 12. Respiration carried out by gills is called …………………… . 13. Respiration through is called Pulmonary respiration. 14. Plants respire through on the leaf and on the stem. 15. …………………… is the pumping organ in the blood circulatory system. 16. Upper two chambers of the heart are called and lower two chambers are called …………………… . 17. The rhythmic contraction followed by its relaxation of the heart is called …………………… . 18. Heart beat can be felt and measured by an instrument called …………………… . 19. …………………… carry blood with more oxygen from heart to body parts. 20. …………………… carry blood with more carbon dioxide from the body parts to the heart.