The rate of the oxygen diffusing from the lungs to the blood in a person has decreased by 20%. Identify as many ways as you can that could have caused this decrease. Explain how the ways you identified above cause the rate of oxygen diffusion from the lungs into the blood to decrease.
In some cells of the brain, when a small molecule called acetylcholine binds to Na+ channels those channels open and Na+ can enter the cell. In an experimental laboratory rat, you observe the rate of Na+ entering the cell is 50% less than normal. a) Identify as many ways as you can that could have caused this decrease in Na+ entering the cell. b) Explain how the ways you identified above could have caused this decrease in Na+ entering the cell.
a) The rate of blood flow to a person’s brain has decreased drastically causing them to pass out. Identify as many changes to the circulatory system as you can that could have caused this decrease in blood flow to the brain.
b) Explain how the changes you identified could have caused this decrease in blood flow to the brain.
This is a figure of a heart with the major arteries labeled. These arteries deliver blood to the muscles of the heart. In a patient, you notice that blood flow to region X of the heart muscle has decreased by 10%. Identify as many ways as you can that could have caused this decrease in blood flow to region X of the heart.
Explain how the ways you identified above could have caused this decrease in blood flow to region X of the heart.
The figure shows an animal cell with the following labeled:
● Potassium (K+) ion concentrations (measured in mM) inside and outside the animal cell
● Membrane potential (-70 mV)
● K+ channel
a) In this situation, there is net movement of K+ ions out of the animal cell through the K+ channel (as indicated by the arrow). What would have to change to cause net movement of K+ INTO the animal cell? Identify as many ways as you can.
b) Explain how the ways you identified above cause K+ to move INTO the animal cell.
The figure shows: ● Alveoli permeable to oxygen (O2) next to a blood vessel ● The concentration of O2 in the alveoli and blood vessel when a person first inhales ● Oxygen molecules represented by white circles ● One oxygen molecule labeled “X”
A scientist is studying sap flow in phloem vessels in three different tree, an American beech, a white oak, and an American chestnut of similar size and age. She found that the composition of the sap was identical among the trees as well as the diameter of their phloem vessels, but the rate of sap flow through the phloem vessels was different. The scientist measured the following pressures at the top (i.e., in the tree crown) and near the bottom (i.e., the base of the trunk) of each phloem vessel.
The same kind of sap flows through three very long, phloem vessels. Each vessel has the same diameter but different flow rates of sap. A scientist measures the pressure of the sap near the beginning and near the end of each phloem vessel.
Which phloem vessel has the greatest flow rate (L/hour) of sap? a) Phloem vessel 1 b) Phloem vessel 2 c) Phloem vessel 3
Explain why the phloem vessel you selected has the greatest flow rate (L/hour) of sap.