48 exam-style questions on Homeostasis — topic D3.3 of Continuity and change in the IB Biology syllabus — with answers and explanations. Samples below; the full set is free with an account.
When blood glucose falls, which hormone stimulates the breakdown of glycogen to glucose in the liver?
Answer: Glucagon
Glucagon, secreted by pancreatic alpha cells, promotes glycogenolysis and gluconeogenesis in the liver, raising blood glucose. Insulin has the opposite effect, lowering blood glucose.
In the nephron, most selective reabsorption of glucose and amino acids occurs in the:
Answer: Proximal convoluted tubule
The proximal convoluted tubule reabsorbs nearly all glucose and amino acids, along with much water and salts, using cells rich in mitochondria and microvilli for active transport.
Which hormone lowers blood glucose concentration?
Answer: insulin
Insulin (from pancreatic β-cells) promotes glucose uptake and storage as glycogen; glucagon raises blood glucose.
In which structure does antidiuretic hormone (ADH) increase water reabsorption?
Answer: collecting duct
ADH raises the permeability of the collecting duct to water, concentrating the urine and conserving water.
State what is meant by homeostasis in a mammal.
Answer: Maintaining a constant internal environment
Homeostasis is the maintenance of internal conditions (such as temperature, pH and glucose) within narrow tolerance limits despite changes in the external environment.
In a negative feedback control system, the role of the effector is to:
Answer: produce a response that reverses the change
In negative feedback the receptor detects the change and the effector produces a response that returns the variable towards the set point, opposing the original deviation.
That was 6 of 48 Homeostasis questions.
Practise all 48 freeStateAO1 · 1–2 marks
One word or one short sentence. No explanation, no working: the mark is for the fact itself.
OutlineAO2 · 1–4 marks
A brief account or summary: the main points in two or three sentences, no evaluation.
DefineAO1 · 1–2 marks
Give the precise meaning — one sentence, the key terms in it, no example needed unless asked.
48 Homeostasis questions — free with an account. Spaced repetition, streaks and full exam simulations included.
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