Cacti and bromeliads have adaptations that allow them to survive in hot, dry climates with limited water availability. Cacti have spines, thick succulent stems that store water, shallow roots, and undergo Crassulacean acid metabolism (CAM) photosynthesis to absorb water at night. Bromeliads form tank-like structures with their leaves to capture water and have CAM photosynthesis. Both plants have thick waxy coatings and store water in their tissues to withstand drought conditions.

1. NURUL FARIHIN BT MOHD RADZI (D20091034866) FHATIN AMIRA BT MUSA (D20091034856) MUNIRAH BT APANDI (D20091034850) EZZA LIYANA BT BADRUL HISHAM (D20091034875) NUR FARHANA BT MOHAMAD MOKHTAR (D20091034852)

2. WHY CACTUS SUITABLE TO GROW IN TEMPERATE REGION ?

11. What is the special characteristic of Bromeliads which make the farmer grow them?

13. Nidularium sp. Nidularium sp. Billbergia sp. Ananas sp.

17. C4 PLANT What are the characteristics of C4 plants?

24. CAM PLANT

25. Crassulacean acid metabolism, also known as CAM photosynthesis, is a Carbon Fixation pathway present in some plants. These plants fix carbon dioxide (CO2) during the night, storing it as the four-carbon acid malate. The CO2 is released during the day, where it is concentrated around the enzyme RuBisCO, increasing the efficiency of photosynthesis. The CAM pathway allows stomata to remain shut during the day, reducing evapotranspiration ; therefore, it is especially common in plants adapted to arid conditions.

26. The CAM cycle is shown below... Notice how all the reactions occur in the same cell but at different times of the day .

28. The fixation step occurs at night with the guard cells open to receive carbon dioxide during the cool night. This process is driven by use of starch to make the PEP required for PEPcarboxylase activity. The malic acid is transported to the vacuole and accumulates there at night. There is a strong pH change in the vacuole at night! During the night

29. During the day The malic acid is transported back to the cytosol for the decarboxylation reaction. This floods the Calvin cycle with carbon dioxide while the guard cells are closed. The energy of course comes from the light reactions and accumulated starch is used the next night for another round of carbon fixation.