#Question id: 11200
#Unit 7. System Physiology – Animal
Action potentials are normally carried in only one direction: from the axon hillock toward the axon terminals. If you experimentally depolarize the middle of the axon to threshold, using an electronic probe, then ________.
#Question id: 10920
#Unit 6. System Physiology – Plant
The pressure-flow model, first proposed by Ernst Münch, Phloem loading at the source and phloem unloading at the sink establish the pressure gradient.
a.) In source tissues, an accumulation of sugars in the sieve elements generates a lower or negative solute potential (ψs).
b.) source tissue, causes a steep drop in the water potential (ψ), due to water potential gradient, water enters the sieve elements and causes turgor pressure (ψp ) decrease.
c.) In sink tissues, phloem unloading leads to a lower sugar concentration in the sieve elements, generating a higher or less negative solute potential.
d.) As the water potential of the phloem rises above that of the xylem, water tends to leave the phloem in response to the water potential gradient, causing a decrease in turgor pressure in the sieve elements of the sink.
Which of the following statements of sink and source tissue is FALSE?
#Question id: 11010
#Unit 7. System Physiology – Animal
Which of the following best explains how sympathetic stimulation affects the heart?
#Question id: 49
#Unit 1. Molecules and their Interaction Relevant to Biology
The equilibrium constant, Keq, for the following reaction is 2 × 105 M: If the measured cellular concentrations are [ATP] = 5 mM, [ADP] = 0.5 mM, and [Pi] = 5 mM, on the basis of the above information calculate the Keq in living cells?
#Question id: 28374
#Unit 5. Developmental Biology
Which of the following proteins bind with dorsal protein and sequester in inactivated form and to prevent ventralizes embryo cell?