Which sequence of events could lead to mass flow in a phloem sieve tube? 1 Sucrose moves into a sieve tube element. 2 Protons (H+) and sucrose molecules move into a companion cell through a co-transporter protein. 3 A very high hydrostatic pressure is produced. 4 The water potential of the sieve tube element decreases. 5 Protons (H+) are actively pumped out of a companion cell. 6 Water moves down a water potential gradient by osmosis.

The diagrams show transverse sections of parts of a plant. In the transverse sections, which tissues transport sucros...

Which statement describes movement through a plant in the apoplast pathway?

Which changes to the water potential and the volume of liquid in the phloem occur when sucrose is moved from the phlo...

Which statement about the blood flow in the cardiac cycle is correct?

Which of these statements about the formation of haemoglobinic acid are correct? 1 It depends on the formation of car...

What can combine with the haem group of a haemoglobin molecule? 1 oxygen 2 carbon dioxide 3 carbon monoxide