Question

rbcs typically have a biconcave disk shape. a scientific study examined the effect of changing the rbc shape and membrane flexibility on its ability to transfer oxygen. for this study, when the rbc membrane was less flexible, the oxygen transfer capacity decreased by 18%. when the rbc was more flexible, the oxygen carrying capacity increased by 21%. when rbcs take on water their membrane initially becomes more flexible.
typical biconcave disc
shape of red blood cells
side view
(cross section)
2.0 μm
top view
7.5 μm

1. what evidence would support the claim that consuming water after exercise helps an athlete’s body maintain homeostasis?

number of rbcs
taking on water
rbc flexibility
rate of oxygen transfer
(1)
increases
decreases
decreases
(2)
increases
increases
increases
(3)
decreases
increases
increases
(4)
decreases
decreases
decreases
chapter 3:
designing an artificial organ
organ transplants save lives, but the demand for organs like kidneys and heart valves far exceeds the supply. to help solve this issue, scientists and engineers have started creating bioengineered artificial organs. these organs are often made from synthetic materials or 3d - printed biological tissues designed to mimic the function of the real organ.
a research team is designing a new artificial heart valve. the goal is to create a model that can survive long - term inside the human body, function reliably, and minimize the risk of rejection. to evaluate design options they consider trade - offs like material strength, cost, durability, and compatibility with the human immune system.
comparing artificial heart valve materials
material
durability
risk of rejection
estimated cost
notes
bovine (cow) tissue
medium
low
$3,000
biologically derived, proven safe and effective
titanium - coated alloy
high
medium
$17,000
very durable, may require blood thinner
polymer (plastic) scaffold
medium - high
low
$6,000
flexible and customizable on its printing

1. which of the following would be considered a constraint in the development of an artificial heart valve?

(1) whether the artificial valve design allows for future upgrades in tubular wireless sensors for tracking heart function in real time.
(2) surgeons may prefer a less invasive procedure that reduces operating time and shortens patient recovery after valve replacement.
(3) the valve must function under high heart rates, opening wide enough to keep up with increased blood flow during physical activity.
(4) the materials used must not trigger an immune response, since they will be in contact with blood for many years.
the artificial valve (bottom) mimics the function of a real heart valve (top), allowing blood to flow in one direction and preventing backflow
(source: biotronik medicali)

Explanation:

To determine the evidence supporting the claim that drinking water after exercise helps maintain homeostasis, we analyze the RBC (red blood cell) data. When an athlete drinks water, RBCs take on water (increasing their number taking on water). From the table, when "Number of RBCs Taking on Water" increases, we look at RBC Flexibility and Oxygen Transfer. The study states that when RBC membrane is more flexible (from taking on water), oxygen transfer capacity increases. Option (2) shows "Number of RBCs Taking on Water" increases, "RBC Flexibility" increases, and "Rate of Oxygen Transfer" increases. This matches the relationship: more water intake → more RBCs taking on water → increased RBC flexibility → increased oxygen transfer, which helps the body (e.g., muscles) get oxygen, maintaining homeostasis (like oxygen and fluid balance after exercise). Other options don't align: (1) shows decreased flexibility and oxygen transfer, (3) has decreased RBCs taking on water, (4) has decreased all, which don't support the claim.

Answer:

(2) increases, increases, increases