EASY
AS and A Level
IMPORTANT
Earn 100

Calculate the volume of filtrate that enters the loops of Henle from the proximal convoluted tubules each minute.

Important Questions on Homeostasis

MEDIUM
AS and A Level
IMPORTANT
Biology for Cambridge International AS & A Level coursebook 2nd Edition Digital Access>Chapter 14 - Homeostasis>Questions>Q 4
Although almost half of the urea in the glomerular filtrate is reabsorbed from the proximal convoluted tubule, the concentration of urea in the fluid in the nephron actually increases as it passes along the proximal convoluted tubule. Explain why this is so. 
EASY
AS and A Level
IMPORTANT
Biology for Cambridge International AS & A Level coursebook 2nd Edition Digital Access>Chapter 14 - Homeostasis>Questions>Q 4

Explain how each of this feature of the cells in the proximal convoluted tubules adapts them for the reabsorption of solutes:

microvilli

EASY
AS and A Level
IMPORTANT
Biology for Cambridge International AS & A Level coursebook 2nd Edition Digital Access>Chapter 14 - Homeostasis>Questions>Q 4

Explain how each of these features of the cells in the proximal convoluted tubules adapts them for the reabsorption of solutes:

many mitochondria

EASY
AS and A Level
IMPORTANT
Biology for Cambridge International AS & A Level coursebook 2nd Edition Digital Access>Chapter 14 - Homeostasis>Questions>Q 4

Explain how each of these features of the cells in the proximal convoluted tubules adapts them for the reabsorption of solutes:

folded basal membranes. 

EASY
AS and A Level
IMPORTANT
Biology for Cambridge International AS & A Level coursebook 2nd Edition Digital Access>Chapter 14 - Homeostasis>Question>Q 5
Discuss how human kidneys can reabsorb so much water from the filtrate that they are able to produce urine four times more concentrated than blood plasma. 
MEDIUM
AS and A Level
IMPORTANT
Biology for Cambridge International AS & A Level coursebook 2nd Edition Digital Access>Chapter 14 - Homeostasis>Question>Q 6

The figure given below shows the relative rate at which fluid flows through nephrons and collecting ducts. If water flows into an impermeable tube such as a hosepipe, it will flow out of the far end at the same rate that it flows in. However, this clearly does not happen in a nephron. Consider what happens in each region, and suggest an explanation for the shape of the graph. 

Question Image

MEDIUM
AS and A Level
IMPORTANT
Biology for Cambridge International AS & A Level coursebook 2nd Edition Digital Access>Chapter 14 - Homeostasis>Questions>Q 7
Aquaporins are found in the cell surface membranes of many plant and animal cells. Explain.
MEDIUM
AS and A Level
IMPORTANT
Biology for Cambridge International AS & A Level coursebook 2nd Edition Digital Access>Chapter 14 - Homeostasis>Questions>Q 8
Use the example of water content of the blood, explain the terms set point and homeostasis.