Ch. 36: Resource Acquisition and Transport in Vascular Plants

Question 1

Describe the forces acting on a water molecule as it travels form the soil, through the root cells, vascular bundles and leaves in a pine tree

Answer 1

Ground => Roots: Diffusion requires ATP; use osmotic force, to make saltier; diffusion => bulk flow
(AKA: root pressure)

Roots => Stem: Diffusion requires ATP (AKA: root pressure)

Stem => Leaves: Hydrostatic pressure works against adhesion and cohesion processes

Leaves => Air: Diffusion

Transpiration pull

Transpiration: flow of H2O from roots through leaf stoma to atmosphere

Question 2

If the xylem were impermeable to water in vascular bundles, how would this affect the transport of sugar sap in the phloem?

Answer 2

without water supply, sugar sap would not be produced.
water is required to help sugar diffuse from the leaves into the phloem–sieve tubes–helps bulk flow

• xylem and phloem are connected/coupled together.
• need to create a pressure flow/osmotic pressure for the transportation of the sugar sap.
• bulk flow, needs ATP

2nd xylem: water (up)
2nd phloem: sugar-sap (mostly down)

Question 3

The leaves produce sugars via photosynthesis and carbon fixation. Which tissues in the plant require these sugars and how are the sugars converted back to usable energy (i.e. ATP).

Answer 3

Roots need ATP to keep their pressure gradient to increase mineral absorption. All live tissues require some type of sugar energy

leaves produce sugar via photosynthesis and carbon fixation.
the roots use ATP to transport ions and water to the shoots
( hydrogen, potassium, nitrate gradient)

Question 4

Adaptations for acquiring resources were key steps in…

Answer 4

the evolution of vascular plants

Question 5

Different mechanisms transport substances…

Answer 5

over short of long distances

Question 6

Transpiration drives..

Answer 6

the transport of water and minerals from roots to shoots via the xylem

Question 7

The rate of transpiration is

Answer 7

regulated by stomata

Question 8

Sugars are transported

Answer 8

from sources to sinks via the phloem

Question 9

Apoplectic route

Answer 9

on cell walls

Question 10

Symplastic route

Answer 10

within the cell

Question 11

Cohesion-Tension Theory

Answer 11

tendency of H2O to stick together

Question 12

Guttation

Answer 12

Root pressure “push”

-i.e. dew on leaves

Question 13

Demography

Answer 13

the study of changes over time in the vital statistics of populations, especially birth rates and death rates

Question 14

Life Table

Answer 14

an age-specific summary of the survival pattern of a population

Question 15

Cohort

Answer 15

a group of individuals of the same age in a population

studied as a group/ group of focus