Teacher sheet · Ages 10–11 · about 45–50 minutes
Deserts: why so dry, and how life copes
Lesson page: echoesof.science/school/deserts/ages-10-11/ · Pupil worksheet: echoesof.science/school/deserts/ages-10-11/print/
Learning aims
- Define a desert by rainfall and know that deserts can be hot or cold, sandy or rocky.
- Explain how latitude, high pressure and rain shadows make deserts.
- Explain why hot deserts have big day–night temperature differences.
- Describe plant and animal adaptations and plan a fair test.
Lesson plan
| Time | Activity |
|---|---|
| 5 min | Starter: is Antarctica a desert? Vote, then reveal. |
| 10 min | Read the text; draw a labelled rain-shadow diagram. |
| 20 min | Set up the shape fair test; weigh after 1 hour and 3 hours. |
| 5 min | Desert survival tricks game. |
| 5 min | Quiz. |
Materials for the experiment
- Three identical paper towels
- Measuring spoon or syringe and a cup of water
- Kitchen scale (1 g or better)
- Three plates
- Sticky tape
- A warm, sunny spot
Safety: Use only water. Wipe up spills straight away. Keep the scale dry.
Common misconceptions
| Pupils may think… | Actually… |
|---|---|
| Deserts are defined by heat. | Deserts are defined by how little rain falls; cold places can be deserts too. |
| Deserts are always hot, even at night. | Dry, clear air lets heat escape, so desert nights can be freezing. |
| Desert animals must find a pond to drink. | Some, like the kangaroo rat, get all the water they need from their food. |
Worksheet answers
- Any two: they lie around 30° north or south where the air has already lost its moisture; high pressure brings few clouds; they lie in a rain shadow behind mountains.
- Plant: a cactus stores water in its stem, bushes grow few leaves or long roots, ephemerals grow only after rain. Animal: the kangaroo rat gets water from seeds and does not sweat, the fennec fox hunts at night, the Namib beetle collects fog.
- Changed: the shape of the towel. Measured: the mass (water lost) after 1 and 3 hours. Kept the same: towel type, amount of water, place, time.
- About 9 times (250 ÷ 28 ≈ 9).
Quiz answers
- How much rain does an arid place get in a year? Less than 250 mm. That is the usual dividing line for arid land.[1]
- About how much of the world's desert area is covered by sand? About 20%. Most deserts are rock and gravel.[3]
- What is a rain shadow? Dry land behind mountains that caught the rain. Moist air drops its rain as it rises over the mountains.[4]
- Why do hot deserts get cold at night? The dry, clear air lets most of the heat escape. About 90% of the day's heat radiates back to the sky.[4]
- Where does a kangaroo rat get its water? From the seeds it eats. It can survive without ever drinking.[5]
- What do ephemeral plants do? Grow, flower and make seeds within a few weeks after rain. They complete their whole life cycle while there is water.[2]
Going further
Find the Sahara, the Atacama, the Namib and Antarctica on a world map. Which lie near 30° north or south? Which one is a cold desert?
Sources used in this lesson
- [1] Deserts: Geology and Resources – What is a desert? (U.S. Geological Survey (General Interest Publication)): reliability High
- [2] Mission: Biomes – Desert (NASA (Mission: Biomes)): reliability High
- [3] Deserts explained (National Geographic Society (Education resource library)): reliability Medium-high
- [4] Deserts (Joshua Tree National Park) (U.S. National Park Service): reliability High
- [5] Animal fact sheet: Merriam's kangaroo rat (Arizona-Sonora Desert Museum): reliability High
- [6] Desert: Biota (Encyclopaedia Britannica): reliability High
Full list with links and a note on each source's reliability: echoesof.science/school/deserts/sources/
Privacy: the lesson pages have no ads, no tracking and no cookies. Quiz answers and game scores stay in the pupil's browser. A short video for each age is coming.