本题目来源于试卷: IB ESS Unit 2: Ecosystems & Ecology，类别为 IB环境系统与社会
[单选题]
Figure: An integrated rice cult j/-cfc*9 rjt9 a8 mnkgn v,+cqiva f-nv ejb5h)g2 y2u.c cg, -nhation system
[Created with BioRender.com]
The illustration shows a rice cultivation system that eliminates the need for fertilizers, herbicides and pesticides by raising ducks in rice paddies. Additionally, Azolla, an aquatic floating fern, is grown in these fields because they harbour blue-green algae that can fix atmospheric nitrogen. This system produces duck, fish and rice for human consumption.
Draw a possible food chain for the rice cultivation system shown in the image.
A. algae → → fish → → duck → → human
B. algae ← ← fish ← ← duck ← ← human
C. insects → → algae → → duck → → human
D. insects ← ← algae ← ← duck ← ← human
参考答案: A
本题详细解析:
Algae is a producer, (Option B), but the arrows show the ffqcgi w.:3r,mj ez:v8 low of energy in the wrong direction. The food chain cannot start with insects (Option C) as it is not an autotroph. Algae do not eat ducks and dm:i8,gvezjc frw: .3qucks do not eat humans (Option D).
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