Practice 2.3 Carbohydrates and lipids with authentic IB Biology exam questions for both SL and HL students. This question bank mirrors Paper 1A, 1B, 2 structure, covering key topics like cell biology, genetics, and ecology. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.
Paper
Level
Question 1
HLPaper 1A
The diagrams show how monosaccharide molecules are joined to form chains in two polysaccharides.
Using the diagram and the table, which diagram and monosaccharide represent glycogen?
| Diagram | Monosaccharide that makes up the chain | |
|---|---|---|
| A. | A | glucose |
| B. | A | maltose |
| C. | B | glucose |
| D. | B | maltose |
Question 2
SLPaper 1A
What type of molecule is formed by the chemical reaction shown in the diagram?
Question 3
SLPaper 1A
The diagram shows a type of fatty acid.
What type of fatty acid is shown?
Question 4
SLPaper 1A
Which type of reaction is the breakdown of starch into sugars?
Question 5
HLPaper 1A
The table shows the mass of different types of fat in some foods.
| Mass per food | ||||
|---|---|---|---|---|
| Food | Saturated fat | Polyunsaturated fat | Monounsaturated fat | Trans fat |
| Palm oil | 50 | 9 | 23 | 0 |
| Canola oil | 7 | 28 | 63 | 0 |
| Sunflower oil | 10 | 40 | 45 | 0 |
| Partially hydrogenated soybean oil | 30 | 10 | 15 | 45 |
Which oil would be least recommended for inclusion in the human diet?
Question 6
HLPaper 1A
Which organic molecules may contain the element sulphur?
Question 7
HLPaper 1A
Olive oil may reduce the risk of coronary heart disease. What is/are the compound(s) responsible for the health benefits of olive oil?
I. Cis unsaturated fatty acids
II. Trans unsaturated fatty acids
III. Saturated fatty acids
Question 8
SLPaper 2
The equation below shows the production of glucose and galactose from lactose. 
1.[1]
Glucose and galactose are examples of monosaccharides. State one other example of a monosaccharide.
2.[1]
There are several different types of carbohydrate. State which type of carbohydrate lactose is.
3.[1]
State the type of chemical reaction that occurs when lactose is digested into glucose and galactose.
4.[3]
Lactase is widely used in food processing. Explain three reasons for converting lactose to glucose and galactose during food processing.
5.[2]
Simple laboratory experiments show that when the enzyme lactase is mixed with lactose, the initial rate of reaction is highest at 48°C. In food processing, lactase is used at a much lower temperature, often at 5°C. Suggest reasons for using lactase at relatively low temperatures.
Question 9
HLPaper 1A
The graph shows the amounts of two substances present in food ingested by a healthy person as it moves along the gut.
Which substances could X and Y be?
Question 10
HLPaper 1A
How is the sequence of DNA conserved?