To easy remember it,
Phloem, has the (f) sound, so it carries food and nutrition like sugars all around the plant, up and down movwment.
while Xylem carries water and minerals, from down the soil up to the plant, only up movement.
1. Trachea itself is not considered a complete organ. It is a part of the breathing system and the only airway to the lungs.
2.Yes rigid organs.
3. Rigid organs constitute part of the endoskeleton of vertebrates.
Answer:
(B) open stomata only at night, limiting water loss because of heat and low humidity.
Explanation:
CAM plants are found in the regions characterized by very hot and dry environmental conditions. These plants reduce the water loss through transpiration by exhibiting CAM photosynthesis.
They open the stomata during night time when the air is cooler and rich in moisture. They take in CO2 during night time and fix it into the oxaloacetate which in turn is converted into malate and is stored in the vacuoles.
During day time, stomata remain closed to prevent water loss and the CO2 trapped during night time (released by decarboxylation of malate) enter the Calvin cycle.