Living Things and Air Unit Summary PDF

Living Things and Air Unit summary/ Air 74 1. Air is a mixture of nitrogen (78%), oxygen dioxide (21%), carbon (0.03%), noble gases (0.9%), water vapour and other gases (0.07%). Oxygen Tests - e e Water and water vapour Carbon dioxide It turns hydrogencarbonate indicator from red to...

Living Things and Air Unit summary/ Air 74 1. Air is a mixture of nitrogen (78%), oxygen dioxide (21%), carbon (0.03%), noble gases (0.9%), water vapour and other gases (0.07%). Oxygen Tests - e e Water and water vapour Carbon dioxide It turns hydrogencarbonate indicator from red to yellow. It relights a glowing splint. [t causes a burning splint to burn more brightly. Both turn dry cobalt chloride paper from blue to pink. | | It turns limewater from colourless to milky. Photosynthesis 7.2 3. word the by d ize mar sum be can is hes ynt tos Pho is. hes ynt tos pho by food own r Plants make thei equation and chemical equation below: light energy absorbed by chlorophyll carbon dioxide + water 6CO, 4. 7.3 6. CsH.;,O¢ + 6H,0 + 60, The following are the significance of photosynthesis: providing food for living things e e E k3 —_— glucose + oxygen maintaining the balance of oxygen and carbon dioxide in Nature d foo a In . ngs thi ng livi ng amo rgy ene of flow the and hip ons ati A food chain shows the feeding rel chain, plants are producers and animals are consumers. Respiration Respiration can be summarized by the word equation and chemical equation below: energy released glucose + oxygen J carbon dioxide + water _> C5H1205 7. T 602 + 6H,0 ‘A comparison of photosynthesis and respiration is given below: Photosynthesis Respiration Raw materials Carbon dioxide and water Food (glucose) and oxygen Products Food (glucose) and oxygen Carbon dioxide and water Where it takes place Takes place only in plants When it takes place | the r unde e c a l ce sen pre the ck dia e plac Tak.es of light Energy is stored in food 68 6CO, and animals | in both plants place I Takes sl Nebatilldspcb il il Takes place all the time Energy is released from food 7.4 Gas exchange in plants and animals The net gas exchange in plants depends on the relative rates of photosynthesis and respiration. 8. In the daytime, there is a net uptake of carbon dioxide and a net release of oxygen. At night, there is a net uptake of oxygen and a net release of carbon dioxide. e e . mis der epi leaf the on a mat sto the h oug thr out d rie car is nts pla Gas exchange in IH9. Main parts of the human breathing system are shown below: 10. nasal cavity trachea bronchus bronchiole . air sac g diaphragm intercostal muscle 3 11. Gas exchange at the air sacs: « 12. 7.5 13. oxygen passes from the air sacs into the blood s sac air the o int d oo bl the om fr es ss pa e id ox di carbon se The . de xi no mo on rb ca and ne oti nic tar, as h suc es Cigarette smoke contains harmful substanc . cer can g lun and es eas dis rt hea es, eas dis ry ato pir res increase risks of re tu Na in en yg ox d an e id ox di on rb ca of e nc la Ba Photosynthesis and respiration are two important processes to maintain the balance of carbon dioxide and oxygen in Nature. and ect eff e ous enh gre the es anc enh e her osp atm the in e xid dio 14. The increasing amount of carbon leads to global warming. 15. 7.6 16. Global warming will result in the melting of ice at polar regions and climate change. Air quality Carbon monoxide, sulphur dioxide, nitrogen oxides and suspended particulates are common air es eas dis ry ato pir res and tem sys ing ath bre the to on tati irri , pollutants. They can cause headaches (e.g. bronchitis and asthma), and even death. 17. The AQHI provides information about air quality. The higher the index, the poorer the air quality. 69