Unit 3 Questions

Question 1

Joins right ventricle to lungs

Answer 1

Pulmonary artery

Question 2

Carries oxygenated blood away from heart

Answer 2

Aorta

Question 3

Carries deoxygenated blood away from kidneys

Answer 3

Renal vein

Question 4

First main blood vessel that an oxygen molecule reaches after being absorbed from an alveolus

Answer 4

Pulmonary vein to left atrium

Question 5

Has the highest blood pressure

Answer 5

Aorta

Question 6

Translocation

Answer 6

Process by which organic molecules (e.g. Sucrose, amino acids) and mineral ions (e.g. K+, Cl-, Mg2+) are transported from one part of a plant to another.

Question 7

Mass flow

Answer 7

Bulk movement of substance through a given channel or area in a specified time

Question 8

Transpiration pull

Answer 8

Column of water being pulled up a xylem as a result of transpiration

Question 9

Cohesion-tension theory

Answer 9

Transpiration pull puts the xylem under tension creating a negative pressure in the xylem. Hydrogen bonds cause cohesion.

Question 10

Evidence supporting mass flow

Answer 10

• pressure in sieve tubes, shown by sap coming out
• conc. of sucrose higher in leaves than respiring cells
• downward flow in phloem in daylight, but ceases with low light
• increases in sucrose levels in leaf followed by similar levels in phloem
• low metabolic activity inhibits translocation
• companion cells possess many mitochondria

Question 11

Evidence against mass flow

Answer 11

• function of sieve plates is unclear(appear to hinder process)
• not all solutes move at same speed
• sucrose is delivered at similar rate to all regions, rather than to ones with lowest conc.