Question

如圖是一個森林生態系統的植被生長情況，其他成分未表示出。有位科學家研究了圖上的光合作用與光照強度之間的關系（圖甲），及葉肉細胞中的相對含水量與光照強度之間的關系（圖乙）。請據圖分析回答：

⑴圖甲中的a點（曲線與橫軸交點）表示__________________________________________；b點（曲線與縱軸交點）時葉肉細胞產生ATP的細胞器是：______________。

⑵能夠反映a點時生理過程及變量關系的是右上圖中的                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

⑶測定森林喬木在炎熱夏季一天中的光合作用時，往往發現光合作用強度要下降，原因是葉肉細胞中缺少_______（生理過程）的原料；與森林中人參、三七等植物光合作用相對應的是圖甲中的曲線__________。

⑷圖乙中表示喬木葉肉細胞的相對含水量與光照強度之間關系的曲線是________。

⑸假設將圖中部分區域的喬木用無色細眼網一棵棵套住，則由于破壞了_________，網內喬木將凋亡。一段時間后，林下的灌木、草本植物也不能生存，其主要影響因素是________________________，試分析其原因________________________________________

Answer 1

⑴此光照強度下，某植物光合作用吸收的CO₂量等于與呼吸作用釋放的CO₂量/此光照強度下，某植物光合作用強度等于呼吸作用強度/此光照強度下，某植物光合速率等于呼吸速率      線粒體；⑵A ；⑶暗反應    Ⅲ   ⑷1   ⑸食物鏈    陽光/光照  喬木凋亡后，陽光直射底層，使底層光照過強，耐陰植物因水分蒸騰過快而死亡

解析:

⑴⑵見答案。⑶炎熱夏季中午植物蒸騰作用過強導致保衛細胞由于過渡失水而使植物氣孔關閉；這樣會造成葉片組織間隙CO₂濃度降低，影響暗反應的進行。人參、三七等植物屬于陰生植物，適合在弱光環境條件下生存，對弱光的利用能力強；對強光的利用能力弱。⑷相對于灌木和草本植物來說，喬木根系發達，吸水力強，葉片相對含水量受光照強度的影響小。