AQA GCSE Biology Foundation (8461), Foundation tier · Ecology › Adaptations, interdependence and competition
Practise Adaptations. 8 exam-style questions plus unlimited generated ones on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Adaptations are features that help an organism survive in the conditions where it normally lives. Expect to classify adaptations as structural, behavioural or functional, and to explain the features of plants, animals and microorganisms (including extremophiles) from information you are given.
Key facts
Adaptation = a feature that helps an organism survive in its normal conditions
Structural = body features (e.g. thick fur, spines)
Behavioural = actions (e.g. migration, huddling)
Functional = processes inside the body, such as metabolism and reproduction (e.g. concentrated urine)
Small surface area to volume ratio → less heat lost (cold places)
Large surface area to volume ratio → more heat lost (hot places)
Extremophile = lives in extreme conditions of temperature, pressure or salt concentration
Example extremophile: bacteria in deep sea vents
Notes
Three types of adaptation
An adaptation is a feature that helps an organism survive in the conditions where it normally lives.
Structural: features of the body, e.g. thick fur, sharp claws, a thick waxy cuticle on leaves, camouflage colouring.
Behavioural: the way an organism acts, e.g. migrating to warmer places in winter, being active at night to avoid the daytime heat, huddling together to keep warm.
Functional: processes inside the body, such as metabolism and reproduction, e.g. a desert animal producing very little sweat and very concentrated urine to save water, or a mammal lowering its metabolic rate while it hibernates.
Hot, cold and dry places
diagram
Cold: thick fur or a layer of fat insulates the body. A large body with small ears has a small surface area to volume ratio, so less heat is lost.
Hot: large ears and thin fur increase heat loss. A large surface area to volume ratio helps an animal lose heat.
A bigger body has a smaller surface area to volume ratio, so it loses heat more slowly: useful in the cold.
Dry (plants): spines instead of broad leaves and a thick waxy cuticle reduce water loss; long or widespread roots absorb as much water as possible; swollen stems store water.
Camouflage, such as white fur in snow or sandy colours in a desert, helps animals hide from predators or approach prey unseen.
Extremophiles
Extremophiles are organisms that can live where conditions are extreme: very hot, under very high pressure, or very salty (high salt concentration).
Example: bacteria living around deep sea vents survive very high temperatures and pressures.
Their enzymes and other proteins keep working in conditions that would denature the enzymes of most organisms.
Answering adaptation questions
Name the feature, then say how it helps in that environment, e.g. 'thick fur traps air, which insulates the body, so less heat is lost'.
How to answer each type of question
Classify an adaptation
1 mark eachGrade 4
A body feature you could see or measure is structural.
Something the organism does is behavioural.
A process inside the body is functional.
Example. Classify each adaptation of a camel as structural, behavioural or functional. (a) Long eyelashes that keep sand out of its eyes. (b) Producing very concentrated urine. (c) Resting in the shade during the hottest part of the day.
Listing features without explaining how each one helps the organism survive.
Saying the organism 'adapted itself' or 'chose' to change. Adaptations come about by natural selection over many generations.
Mixing up surface area with surface area to volume ratio: in the cold, a small ratio reduces heat loss.
Calling migration or huddling a structural adaptation. They are behavioural.
Writing that extremophiles 'live in extreme places' without naming the condition (temperature, pressure or salt).
More tips
Memory tricks
S-B-F: Structural = what it looks like, Behavioural = what it does, Functional = what goes on inside.
Big and round keeps heat around: large, compact bodies have a small surface area to volume ratio.
For every feature, ask 'so what?': feature → effect → how that helps survival.
Exam technique
Explain questions usually give 1 mark for the feature and 1 mark for how it helps. Always pair them up.
Unfamiliar organisms are common. The clues you need are usually in the question.
Use scientific words: insulation, camouflage, surface area to volume ratio, water loss, denatured.
What each grade needs
What you need to be able to do, from the first marks up to the top grade.
Grade 3
Define an adaptationA feature that helps an organism survive in the conditions where it normally lives.
Grade 4
Classify adaptations as structural, behavioural or functionalStructural means body features, behavioural means what it does, and functional means processes inside the body.
Grade 5
Define an extremophile and give an exampleAn organism that lives in extreme conditions of temperature, pressure or salt concentration, e.g. bacteria in deep sea vents.
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy4 marks
Organisms have adaptations that enable them to survive in the conditions in which they normally live.
(a) Which is a behavioural adaptation? Tick (✓) one box.[1]
A hedgehog hibernates during the winter.
A polar bear has a thick layer of fat.
A cactus stores water in its stem.
A desert rat produces very concentrated urine.
(b) Which is a functional adaptation? Tick (✓) one box.[1]
A camel has long eyelashes.
An Antarctic fish makes antifreeze proteins in its blood.
Penguins huddle together in cold weather.
A cactus has spines instead of leaves.
(c) Bacteria that live near deep-sea vents are extremophiles. Give two extreme conditions that these bacteria are adapted to.[2]
Show the answer and mark scheme
(a)Answer: A hedgehog hibernates during the winter.
(b)Answer: An Antarctic fish makes antifreeze proteins in its blood.
(c)
high temperature
high pressure
no light
high concentrations of dissolved chemicals / minerals
Question 2Medium7 marks
Cacti are plants that live in hot deserts where there is very little rain.
(a) Cacti have spines instead of broad, flat leaves. Explain how this helps a cactus to survive in the desert.[2]
(b) The stem of a cactus is thick and swollen. Suggest why.[1]
(c) The stem is covered by a thick layer of wax. Explain how this helps the cactus to survive.[1]
(d) Some cacti have long roots that grow deep into the ground. Others have shallow roots that spread over a wide area. Suggest how each type of root helps a cactus to obtain water.[2]
(e) The stem of a cactus is green. Suggest why this is important for the cactus.[1]
Show the answer and mark scheme
(a)
smaller surface area (for evaporation) / fewer stomata
(so) less water is lost by transpiration / evaporation
(b)
it stores water
(c)
it reduces water loss by evaporation / it is waterproof
(d)
deep roots reach water far below the surface
shallow, widespread roots absorb rainwater quickly over a large area (before it evaporates)
(e)
the stem photosynthesises / contains chlorophyll, because the spines cannot photosynthesise (so the stem must make glucose)