IGCSE Biology
2026 - 2028
Syllabus Checklist
Topic 7: Human Nutrition
1 Diet
Describe what is meant by a balanced diet
.
State the principal dietary sources and describe the importance of:
▪ Carbohydrates
▪ Fats and oils
▪ Proteins
▪ Vitamins ( C and D
) ▪ Mineral ions ( calcium and iron
) ▪ Fibre
▪ Water
.
State the causes of scurvy
and rickets
.
2 Digestive System
Identify in diagrams and images the main organs of the digestive system
:
▪ Mouth
, oesophagus
, stomach
, small intestine
(duodenum & ileum), large intestine
(colon, rectum, anus).
Associated organs: salivary glands
, pancreas
, liver
, gall bladder
.
Describe the functions of these organs in relation to:
▪ Ingestion
▪ Digestion
▪ Absorption
▪ Assimilation
▪ Egestion
.
3 Physical Digestion
Describe physical digestion
as the breakdown of food into smaller pieces without chemical change.
State that physical digestion increases the surface area
of food for enzyme action.
Identify in diagrams the types of human teeth
: incisors, canines, premolars, molars.
Describe the structure of a tooth – enamel
, dentine
, pulp
, nerves, blood vessels, and cement
.
Describe the functions of the types of teeth in the physical digestion
of food.
Describe the function of the stomach
in physical digestion.
Chemical Digestion
Describe chemical digestion
as the breakdown of large insoluble molecules into small soluble molecules.
State the role of chemical digestion in producing small soluble molecules for absorption
.
Describe the functions of enzymes: amylase
→ simple sugars, protease
→ amino acids, lipase
→ fatty acids + glycerol.
State where in the digestive system amylase
, protease
, and lipase
are secreted and act.
Describe the functions of hydrochloric acid
in gastric juice – kills microbes and provides acidic pH for enzymes.
Describe digestion of starch
: amylase → maltose, then maltase → glucose (on intestinal membranes).
Describe digestion of protein
: pepsin (works in acidic stomach) and trypsin (works in alkaline small intestine).
Explain that bile
is an alkaline mixture that neutralises acidic food from the stomach to create a suitable pH for enzyme action.
Outline the role of bile
in emulsifying fats and oils
to increase surface area for chemical digestion.
4 Absorption
State that the small intestine
is the region where nutrients are absorbed.
State that most water
is absorbed from the small intestine, but some from the colon
.
Explain the significance of villi and microvilli
in increasing the surface area for absorption.
Describe the structure of a villus
.
Describe the roles of capillaries
and lacteals
in villi.
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