4. Write the scientific term:

   The modification of the structure, function or behavior of living organisms to suit the conditions of the environment.
   Plants that capture & feed on insects.

5. Give reasons for the following :

1. The feet of camels are thick pads.

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2. The legs & beaks of herons are long & thin.

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3. The limbs of dolphins are paddles & those of bats are wings.

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4. Insectivorous plants capture insects.

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6. Fill in the blanks:

Animal	Modified organ	Function
Monkey	Long thin fingers
Vulture		Tear the prey
	Flat pad	Walking in the desert
Horse		Running
	Paddles
	Webbed feet (palms)

Animals adapt to the conditions of their environment with different methods.

• The temperature in winter is low & not suitable for some organisms such as frogs & toads. These animals bury themselves in mud, they stop feeding & reduce their bodies vital activities & they sleep through winter.

• During spring, when the temperature is suitable, they wake up & their bodies activities return back to normal.

• Desert animals aestivate during summer, (i.e. they sleep in their burrows) to avoid the high temperature

& shortage in water.

• J erboa, desert snails & some insects are some of the animals which survive through summer by aestivation.

• The quail is one of the birds which live in polar regions during spring. In winter, quail birds fly towards warm regions where they reproduce.

Elodea & hyacinth are aquatic plants which adapt to the conditions of their environment .

Aquatic plants don’t have enough oxygen or light. Water currents are strong.

E lodea plant which lives submerged in water adapts to the environment as follows:

Oxygen is needed for respiration & to help the plant float near water surface to get light.

• The conditions of the desert are

• Rare (shortage) rainfall

• Strong wind

• High temperature during the day & low temperature during night

1. Calmagrostis plant has roots that extend deeply in the soil to get ground water.

• The leaves are small spiral & ribbon – like.

• The stomata (pores on the surface) are few, this saves water & reduce transpiration (evaporation).

2. O puntia & cactus

• store rain water in their stems.

• Their stems are short to overcome wind.

• Their leaves are modified to spines to reduce transpiration.

• They are covered with wax to reduce transpiration.

Examples:

1. The leaf insect matches the colour & shape of a leaf, therefore predating birds don’t see it easily.

2. The stick insect matches the colour & shape of a branch.

3. C hameleon (a type of lizard ) has the colour of its environment. It hides to capture its food of insects.

The camel is the desert ship:

The camel has many features that help it to adapt with the conditions of the desert (water shortage – high temperature during day & low temperature during night – strong wind).

1. The eyes have a large number of lacrymal (tear) glands & long eyelashes to protect the eyes from sand storms .

2. The ears are small & are covered with dense hair to prevent dust from going in the ears.

3. The fur that covers the vital organs is thicker than that covers that rest of the body. The fur is heat insulator which keeps the body warm when the temperature is low at night.

4. The thick flat pads help the camel in walking on soft hot sand.

5. The upper lip is forked & the enamel of the teeth is strong, therefore the camel can eat spiny cactus without being harmed.

6. The hump stores excess food in the form of fat, therefore the camel can survive for months without eating food.

7. The body temperature of the camel can rise from 34^o to 41^o during day without sweating. (remember that the temperature of healthy human has to stay 37^o therefore he’ll sweat a lot to cool his body if he’s in the desert).

8. T he camel can drink a huge amount of water in one time & store it in its body, therefore it can go in the desert without drinking for a long time.