Plant Nutrition and Transport

Question 1

What is the main difference between ectomycorrhizae and endomycorrhizae?

A. Hyphae of ectomycorrhizae form a sheath around the root from the outside, whereas hyphae of endomycorrhizae enter cells of the root

B. Hyphae of endomycorrhizae form a sheath around the root from the outside, whereas hyphae of ectomycorrhizae enter cells of the root

Answer 1

A

Question 2

What are the three levels of plant transport?

Answer 2

1. Uptake and loss of water and solutes by individual cells
2. Short-distance transport of substances from cell to cell in tissues/organs
3. Long-distance transport of sap within xylem and phloem through whole plant

Question 3

Symplast

Answer 3

Continuum of cytosol linked by plasmodesmata

Question 4

Transmembrane

Answer 4

Molecules repeatedly cross plasma membranes and cell walls

Question 5

Apoplast

Answer 5

Water-filled cell walls and intercellular spaces

Question 6

What are some functions of the vacuole?

Answer 6

1. Hold water and toxic waste
2. Enlarge cell
3. Contain unpalatable/poisonous compounds to deter herbivores

Question 7

Transpiration

Answer 7

Loss of water vapor from leaves

Question 8

What does transpiration cause?

Answer 8

1. Xylem sap rises against gravity
2. Carries minerals to shoots
3. Evaporative cooling, preventing denaturing of proteins

Question 9

Guttation

Answer 9

Exudation of water droplets that can be seen in the morning on grass

Question 10

Cohesion-Tension theory

Answer 10

1. Plants expend no energy on bulk flow; sun’s energy indirectly powers transpiration.
2. Hydrogen bonding in water makes it cohesive, tension exerted on water by evaporation at plant’s surface pulls on a continuous stream of water from soil

Question 11

What does adhesion do in respect to water?

Answer 11

Makes it stick to walls

Question 12

Photosynthesis-Transpiration Compromise

Answer 12

Rate of transpiration will be greatest on sunny, warm, windy days that increase evaporation of water

Question 13

Adaptations for xerophytes

Answer 13

1. Small, thick, leaves reducing leaf surface area relative to leaf volume
2. During driest months, some desert plants shed leaves, while others subsist on stored water.
3. Stomata located in depressions that shelter pores from dry wind
4. Trichomes keep humidity higher in depressions than in surrounding atmosphere.
5. Cacti can tolerate high leaf temps

Question 14

Translocation

Answer 14

Sugar loading into phloem causes water to enter by bulk flow from adjacent xylem

Accumulation of sugar in sink cells reduces solute concentration of phloem, resulting in bulk water flow into xylem