Three plants are studied. Plant X: the first stable product is a 3-carbon compound, there is no…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Three plants are studied. Plant X: the first stable product is a 3-carbon compound, there is no wreath of large cells round the veins, and photosynthesis is best near . Plant Y: the first stable product is a 4-carbon compound, the veins are ringed by large cells, and photosynthesis is best near . Plant Z: RuBisCO works in the cells that touch the air spaces, and it has strong photorespiration. (a) Which plants are C3 and which is C4? (b) Where does RuBisCO work in plant Y? (c) Why does plant Y do well on a hot day?
Need a reminder? The key ideaShow
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The groups. X has a 3-carbon first product and no Kranz anatomy: C3. Y has a 4-carbon first product and Kranz anatomy: C4. Z has strong photorespiration and RuBisCO in the mesophyll: C3.
Step 2. RuBisCO in Y. In the bundle sheath cells.
Step 3. The hot day. Carbon dioxide is concentrated round RuBisCO in the bundle sheath cells, so oxygen has little chance to bind. Y avoids photorespiration, and its temperature optimum is high.
Answer: (a) X and Z are C3, Y is C4; (b) in the bundle sheath cells; (c) no photorespiration and a high temperature optimum.
Discussion (0)
Log in to join the discussion.
Loading…