Question

如圖是一個森林生態(tài)系統(tǒng)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(guān)系（圖甲），及葉肉細胞中的相對含水量與光照強度之間的關(guān)系（圖乙）。請據(jù)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(chǎn)生ATP的細胞器是：______________。

⑵能夠反映a點時生理過程及變量關(guān)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(fā)現(xiàn)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(yīng)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(guān)系的曲線是________。

⑸假設(shè)將圖中部分區(qū)域的喬木用無色細眼網(wǎng)一棵棵套住，則由于破壞了_________，網(wǎng)內(nèi)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(yīng)    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(wèi)細胞由于過渡失水而使植物氣孔關(guān)閉；這樣會造成葉片組織間隙CO₂濃度降低，影響暗反應(yīng)的進行。人參、三七等植物屬于陰生植物，適合在弱光環(huán)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(fā)達，吸水力強，葉片相對含水量受光照強度的影響小。