Hot Deserts

Question 1

Deserts can be cold or hot. But what are they always?

Answer 1

Deserts are always dry.

Question 2

What is the maximum amount of rainfall for a desert to have each year?

Answer 2

Deserts must have less than 25cms of rainfall per year to be classified as a desert.

Question 3

What is an ecosystem?

Answer 3

An ecosystem is a natural system showing the interaction of living and non-living elements.

Question 4

Where are hot deserts found?

Answer 4

Hot deserts are found in bands that are 20-30 degrees north and south of the equator. They are found at the Tropic of Cancer and the Tropic of Capricorn.

Question 5

Describe the rain shadow effect.

Answer 5

Prevailing wind comes from across an ocean, or a sea. The warm, moist air rises, and as it gets further up, it cools and condenses, forming clouds. The dry air then sinks and warms on the other side of the mountain.

Question 6

Name one example of a biotic element.

Answer 6

Biotic elements:
- Fish
- Seaweed
- Frogs
…etc.

Question 7

Name one example of an abiotic element.

Answer 7

Abiotic elements:

• Sunlight
• Rocks
• Water
• Air

Question 8

Why are deserts cold at night?

Answer 8

Deserts are cold at night because in the daytime, the sun causes the desert to heat up. Now, in the night, when there is not sun, the daytime warmth rises up and out of the sand, but then just disappears into the atmosphere, as there are no clouds to trap the heat in and keep the desert nice and warm.

Question 9

Why are some animals nocturnal?

Answer 9

Some animals are nocturnal so that they can avoid the hot daytime temperatures.

Question 10

Why do some animals live underground?

Answer 10

Some desert animals’ habitats are underground, so that it gives them a cool place to stay during the day, yet an insulated place in the night.

Question 11

Why do some animals have light-coloured fur?

Answer 11

Some animals have light-coloured fur as dark colours absorb heat, and light colours reflect heat.

Question 12

Why do some animals have large ears?

Answer 12

Some animals have large ears, which can flap around, for use as a fan. Also, they are thin, and so any blood that enters that area of the animal’s body is chilled slightly by the desert breeze, and so is cooler when it re-enters the rest of the body.

Question 13

Why do some animals have bushy tails?

Answer 13

Some animals have bushy tails for use as a sort of portable parasol for their back when out foraging for food in the daytime.

Question 14

Why do some animals have furry feet?

Answer 14

Some animals have furry feet so that they are protected against the scorching sand/rocks.

Question 15

Name 3 camel adaptations to life in the desert.

Answer 15

Camel adaptations to life in the desert:

• Hair on back to protect from the sun
• Hump for storing food and water
• Long legs to keep the camels off the hot sands
• Padded feet to stop the camels for sinking into the sand and to protect them from the heat as well.
• Leathery mouth to protect when eating spiky plants such as cacti
• Stretchy and closable nostrils to keep the sand out.
• Long and extra sets of eyelashes to keep the sand out of their eyes.

Question 16

Name 1 cactus adaptations to life in the desert.

Answer 16

Cactus adaptations to life in the desert:

• Spikes instead of leaves to deter predators and to prevent moisture loss
• Very wide, shallow roots to absorb the rainwater quickly
• Thick, waxy skin and spikes; both reduce loss from transpiration
• Water can be stored in the trunk and the skin can expand to store large amounts of food and water during a flash flood

Question 17

What is desertification?

Answer 17

Desertification is when deserts spread into semi-deserts around them, turning them into deserts.

Question 18

Name two causes of desertification?

Answer 18

Causes of desertification:

• Deforestation - trees are being chopped down, often for use as firewood
• Over grazing - too many animals are eating grass more quickly than it can grow
• Population growth - the number of people in the world is getting bigger
• Climate change - there is a permanent change in the temperature and the rainfall patterns

Question 19

Name two effects of desertification?

Answer 19

Effects of desertification:

• Desert enlargement - deserts are becoming bigger over time
• Lower food production - there is a decrease in the amount of food produced
• Soil degradation - the soil is becoming weaker at supporting the plant’s life
• Extinction - animals are being wiped out by loss of habitat and/or feeding areas

Question 20

Where is the Mojave desert?

Answer 20

The Mojave desert is in the south west of the United States of America. It is in four states: California, Utah, Arizona and Nevada.

Question 21

What are some of a desert’s resources?

Answer 21

Some of the desert’s resources:

• Sunshine
• Wind
• High daytime temperatures
• ‘Stunning’ natural scenery
• Rock and sand
• Unique wildlife
• Water underground
• Open space