IB Biology SL D3.3 Homeostasis Questions

Practise IB Biology SL D3.3 by tracing blood-glucose and temperature feedback, comparing diabetes types and linking monitored variables to responses.

47 questions in this syllabus scope, with question parts counted together.

Exam analysis

SL · 2010–2025

Papers with this topic44 / 141in the analysed sample

Latest appearanceNovember 2025

Tagged question parts66

Paper types5

Most tested objectives

D3.3.3—Blood glucose regulation20 papers
D3.3.4—Diabetes14 papers
D3.3.5—Thermoregulation6 papers
D3.3.6—Thermoregulation mechanisms5 papers
D3.3.1—Homeostasis definition2 papers

Common question formats

Definition or recall
Process explanation
Data analysis
Diagram interpretation
Calculation
Structured response

Recent exam appearances

November 2025Paper 2 SL · TZ1Q6(a), 6(b)[ 11 ]

November 2025Paper 1A SL · TZ1Q21[ 1 ]

May 2025Paper 1A SL · TZ3Q22[ 1 ]

141 papers analysed · Tagging incomplete

Exam points

Define homeostasis and explain how negative feedback restores internal variables towards set points.
Trace insulin and glucagon responses to high or low glucose and interpret regulation data.
Distinguish type I beta-cell loss from type II insulin resistance using risk and treatment evidence.
Trace temperature feedback and predict vasodilation, sweating, shivering or heat production.

Covered syllabus points

D3.3.1—Homeostasis definition D3.3.2—Negative feedback loops D3.3.3—Blood glucose regulation D3.3.4—Diabetes D3.3.5—Thermoregulation D3.3.6—Thermoregulation mechanisms

Exam points

Define homeostasis as maintaining a stable internal environment within narrow limits.
Identify variables controlled by homeostasis, including blood pH, water balance and blood glucose.

[Maximum number: 1]

Which of the following are controlled by homeostasis?

I. Blood pH
II. Water balance
III. Blood glucose concentration

I and II only

I and III only

II and III only

I, II and III

Exam points

Explain how negative feedback opposes a change and returns a variable toward its set point.

[Maximum number: 4]

Feedback control is used to regulate the levels of variables in the blood system.

Discuss the use of positive and negative feedback to control levels of variables.

Exam points

Describe beta-cell insulin secretion when blood glucose rises and alpha-cell glucagon secretion when it falls.
Explain how insulin promotes glucose uptake or storage, while glucagon stimulates glycogen breakdown in the liver and muscle to raise blood glucose.

[Maximum number: 1]

The graph shows blood glucose levels over the course of a day.

What could explain the trend in glucose levels between 20:00 and 23:00?

Increasing insulin concentration forming glycogen from glucose

Decreasing insulin concentration forming glucose from glycogen

Increasing glucagon concentration forming glycogen from glucose

Decreasing glucagon concentration forming glucose from glycogen

Exam points

Distinguish Type 1 diabetes, caused by pancreatic beta-cell destruction and insufficient insulin, from Type 2 diabetes, involving reduced insulin response.
Link lifestyle factors such as BMI and diet to Type 2 diabetes risk, and interpret evidence about insulin sensitivity.

[Maximum number: 2]

A nomogram can be used to determine the body mass index (BMI) of an individual.

Explain how measurement of BMI could help to assess whether a person has an increased risk of type II diabetes.

Exam points

Explain hypothalamic detection and negative feedback in human temperature control.
Relate sweating, shivering and skin blood-flow changes to heat loss or heat gain.

[Maximum number: 1]

What helps to directly regulate body temperature in humans?

Melatonin secreted by the pineal gland

Thyroxin secreted by the thyroid gland

Glucagon secreted by $\alpha$ cells of the pancreas

Exocrine secretions by the pancreas

Exam points

Explain how vasodilation and sweating increase heat loss when body temperature is high.
Explain how shivering and brown fat generate heat in cold conditions.

[Maximum number: 1]

What occurs if human body temperature decreases?

Thyroxin secretion decreases

Vasodilation of skin arterioles

Sweating increases

Shivering increases

[Maximum number: 11]

Feedback control is used to regulate the levels of variables in the blood system.

(a)

Discuss the use of positive and negative feedback to control levels of variables.

[ 4 ]

(b)

Describe the mechanisms used to keep blood glucose levels within narrow limits in humans.

[ 7 ]

All question bank results loaded

a	pancreas cells monitor blood glucose concentrations;
b	glucagon secreted by alpha cells and insulin secreted by beta cells;
c	glucagon/insulin/hormones secreted into/transported by bloodstream;
d	insulin secreted when glucose concentration rises/is high;
e	insulin stimulates uptake of glucose by liver/muscle/body cells;
f	insulin stimulates conversion of glucose to glycogen (in liver/muscle cells);
g	insulin stimulates body cells to use glucose instead of fat in cell respiration;
h	glucagon secreted when glucose concentration falls/is low;
i	glucagon stimulates breakdown of glycogen to glucose (by liver/muscle cells);
j	negative feedback (is used to regulate blood glucose concentration);

Exam analysis

Most tested objectives

Common question formats

Recent exam appearances

Covered syllabus points

Question 1

Question 1

Question 1

Question 1

Question 1

Question 1

Question 1

Question (a)

Question (b)