When answering a six mark question it is important that you:
1) write at least six points explained
2) write in paragraphs, or else you will loose a mark for spag (spelling, punctuation and grammar)
3) Read the question so that you understand what exactly the question is asking. Students usually loose marks because they have misunderstood what they need to do.
Explain how ADH controls water levels in the body using negative feedback mechanism. (6 marks).
MODEL ANSWER
ADH is a hormone secreted by the pituitary gland. ADH helps to control the water content of the blood. If the water content is too low or high, ADH helps by making the kidneys either absorb more or less water.
If the water content of the blood is too low, the pituitary gland in the brain, secretes a lot of ADH. The ADH causes the kidneys to reabosorb more water. This means there is now sufficient water content in the body. Only a small volume of concentrated urine is produced.
Likewise, if the blood has too much water content, the pituitary gland secretes less ADH. This means the kidneys do not reabsorb large amounts of water, only a small amount. So, a large volume of dilute urine is produced.
Finally, this is an example of the mechanism, negative feedback. This helps to keep water levels constant.
YOU ARE READING
B3/ Further additional science
Non-FictionRevision on B3- Using chemistry. This is for Year 11 exams on further additional/ triple science. Please follow and vote
