AQA
A-Level
BIOLOGY
Organisms Respond to Changes in Environments
Principles of Homeostasis and Negative Feedback
Time allowed
59 minutes
QUESTION PAPER
Score Percentage
/49 %
4.1 | CELL BIOLOGY | QUESTION PAPER 1 1
,(a) The control of water balance in the body involves negative feedback.
(i) Describe what is meant by negative feedback.
...............................................................................................................
...............................................................................................................
...............................................................................................................
(1)
(ii) Water is removed from the body via the kidneys. Give two other ways in which
water is removed from the body.
1 ............................................................................................................
2 ............................................................................................................
(2)
(iii) Name the part of the brain which acts as the coordinator in the control of water
balance.
...............................................................................................................
(1)
(b) Figure 1 shows the cells lining the collecting duct in a human kidney. ADH
molecules bind to the receptor proteins and this triggers the vesicles containing
aquaporins to bind with the plasma membrane next to the lumen. Figure 2 shows
an aquaporin which is a large channel protein.
Figure 1
, Figure 2
(i) From which gland is ADH released?
...............................................................................................................
(1)
(ii) Use the information given to explain how ADH increases the movement of
water from the lumen of the collecting duct into the blood.
A-Level
BIOLOGY
Organisms Respond to Changes in Environments
Principles of Homeostasis and Negative Feedback
Time allowed
59 minutes
QUESTION PAPER
Score Percentage
/49 %
4.1 | CELL BIOLOGY | QUESTION PAPER 1 1
,(a) The control of water balance in the body involves negative feedback.
(i) Describe what is meant by negative feedback.
...............................................................................................................
...............................................................................................................
...............................................................................................................
(1)
(ii) Water is removed from the body via the kidneys. Give two other ways in which
water is removed from the body.
1 ............................................................................................................
2 ............................................................................................................
(2)
(iii) Name the part of the brain which acts as the coordinator in the control of water
balance.
...............................................................................................................
(1)
(b) Figure 1 shows the cells lining the collecting duct in a human kidney. ADH
molecules bind to the receptor proteins and this triggers the vesicles containing
aquaporins to bind with the plasma membrane next to the lumen. Figure 2 shows
an aquaporin which is a large channel protein.
Figure 1
, Figure 2
(i) From which gland is ADH released?
...............................................................................................................
(1)
(ii) Use the information given to explain how ADH increases the movement of
water from the lumen of the collecting duct into the blood.
