Adaptive features — Cambridge IGCSE Biology
Adaptive features as inherited features that aid survival and reproduction, with hydrophyte and xerophyte examples.
Revision notes
2 short notes, in the order of the specification. Each one in short:
An adaptive feature is an inherited feature that helps an organism to survive and reproduce in its environment. It can be a body structure, a way the body works or a pattern of behaviour, but it must be inherited. For example, a polar bear's white fur gives camouflage and its thick fat layer gives insulation.
Hydrophytes and xerophytes
SupplementHydrophytes are plants adapted to live in water, and xerophytes are plants adapted to dry places. A water lily has large air spaces so it floats, stomata on the upper leaf surface and a thin cuticle. Cactus and marram grass have a thick waxy cuticle, spines or rolled leaves, and sunken stomata that reduce water loss.
Exam questions
6 exam-style questions (14 marks), each with its mark scheme.
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Quick check questions
Define adaptive feature.
Show answer
An inherited feature that helps an organism to survive and reproduce in its environment.
Why is a skill learned during life not an adaptive feature?
Show answer
It is not inherited.
Supplement Where are the stomata on a floating water lily leaf?
Show answer
On the upper surface.
Supplement Why do xerophytes have a thick waxy cuticle?
Show answer
To reduce evaporation of water from the leaf surface.
Frequently asked questions
What is an adaptive feature?
An adaptive feature is an inherited feature that helps an organism to survive and reproduce in its environment. It can be a body structure, such as the shape of a beak, a way the body works, such as producing concentrated urine, or a pattern of behaviour. A skill learned during life is not an adaptive feature.
How are xerophytes adapted to dry conditions?
Supplement Xerophytes have features that reduce water loss. A thick waxy cuticle reduces evaporation, and leaves reduced to spines give a smaller surface area. Marram grass has rolled leaves with hairs that trap humid air, and sunken stomata reduce diffusion of water vapour. Fleshy stems store water, and long or widespread roots absorb it.
How are hydrophytes adapted to living in water?
Supplement Hydrophytes such as the water lily have large air spaces in their leaves and stems, which make the plant float so leaves are near the light. Stomata are on the upper surface of floating leaves so they can exchange gases with the air. They have a thin or no waxy cuticle, small roots and little xylem.
How is a polar bear adapted to its environment?
A polar bear has white fur, which camouflages it against the snow so prey find it harder to see it. It also has a thick layer of fat, which provides insulation so less heat is lost. In exams, link each feature to what it does and explain how that helps the animal survive.
Written and checked against the Cambridge IGCSE Biology (0610) specification · Updated October 2026