Consumption efficiency is the proportion of production at one trophic level that is eaten by, or ingested, by the next trophic level which of the following are correct statement ?

A.Consumption efficiencies higher in  forests than grassland

B-In aquatic ecosystems consuption efficiencies of hervivore are greater than terrestrial hervivore

C- Consumption efficiencies for carnivores are typically higher than those of herbivores

D-Primary production consumption is increased where it is high in nutrients such as nitrogen and phosphorus

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#Question id: 13205

#Unit 6. System Physiology – Plant

The mechanisms that regulate the loading of sucrose from the apoplast to the sieve elements by the sucrose–H+ symporter await characterization. Possible regulatory factors include the following:

a) The solute potential or, more likely, the turgor pressure of the sieve elements

b) Sucrose concentration in the apoplast

c) The available number of symporter protein molecules

Which one of the mechanism that involve to regulate the loading of sucrose?

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#Question id: 13206

#Unit 6. System Physiology – Plant

Given below are some of the statements that regulate the sucrose loading mechanism;

A) The solute potential or, more likely, the turgor pressure of the sieve elements

B) Sucrose concentration in the apoplast

C) The available number of symporter protein molecules

Possible observation given on how to avoid regulation;

i) increase in sieve element turgor above a certain threshold would lead to a compensatory increase in loading

ii) High sucrose concentrations in the apoplast would increase phloem loading

iii) SUT1 transporter mRNA and protein have been lower after 15 hours of darkness than after a light treatment. These data suggest that the concentration of SUT1 transporter molecules could regulate loading

iv) Decrease in sieve element turgor below a certain threshold would lead to a compensatory increase in loading

v) The transporter mRNA and protein high in darkness than lower in the light treatment

Which of the following combinations represents correct observation?

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#Question id: 13207

#Unit 6. System Physiology – Plant

The polymer-trapping model explains symplastic loading in plants with intermediary-type companion cells, this model makes three prediction; which one of the following prediction is INCORRECT?

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#Question id: 13208

#Unit 6. System Physiology – Plant

The polymer trapping model explains that, Plasmodesmata between the  Bundle sheath cell  and intermediary cells must be smaller that allows only selective sugar to diffuse from this Plasmodesmata such as;

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#Question id: 13209

#Unit 6. System Physiology – Plant

After unloading, the sugars are transported to cells in the sink by means of a short-distance transport pathway. This pathway has also been called,

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#Question id: 13210

#Unit 6. System Physiology – Plant

In Cohesion–Tension Theory, the pressure gradients needed to move water through the xylem could result from