1. Adaptations for survival
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2. Questions to think about…
What are the types of adaptations?
How do adaptations improve chances of survival?
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3. Adaptations
Living things that can survive in their natural habitats are said to be adapted to their environment.
Organisms that are adapted to their environment are able to:
get air, water and food
cope with physical conditions such as temperature and light
protect themselves from their enemies
reproduce
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4. Adaptations
Special characteristics that help organisms survive in their natural habitats are called adaptations.
Adaptations
structural
behavioural
special body parts of an
organism that help it to
survive in its natural habitat,
for example, its colour,
shape and body covering
special ways an organism
behaves to survive in its
natural habitat
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5. Adaptations for breathing in water
Aquatic animals have to breathe in oxygen that is dissolved in the water or from the air above the water.
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6. Gills
Animals that breathe in oxygen that is dissolved in the water usually have gills.
When oxygen-rich water passes over the gills, dissolved oxygen is taken in and carbon dioxide is given out.
Gills can be found in aquatic animals like fish, shrimps and tadpoles, as well as in some insects like dragonfly nymphs.
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7. Gill chambers
There are animals which breathe with gills but can also stay out of water for short periods of time.
These animals, such as crabs and mudskippers, have gill chambers to store water and keep the gills wet.
When the animals are on land, they can use the oxygen from the water stored in the gill chambers.
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8. Skin
Some aquatic animals use their skin to take in oxygen that is dissolved in water.
The skin is usually thin and soft, and kept wet all the time.
Examples of these animals include aquatic worms like tubifex worms and flatworms, and amphibians like frogs and toads.
Frogs and toads can breathe through their nostrils when on land.
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9. Air tube
Many aquatic insects have to take in oxygen from the air directly using air tubes.
Mosquito larvae and pupae, water stick insects and water scorpions, all have air tubes.
These tubes extend from their bodies and stick out above the water surface to get oxygen.
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10. Air bubble
Other aquatic insects like water beetles and water spiders trap air bubbles by using their adapted wings, legs or hairy bodies.
In this way, they carry their own supply of air and can spend time in the water to hunt for food.
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11. Special nostrils
Mammals cannot breathe in oxygen that is dissolved in water, but can only breathe in oxygen from the air through their lungs.
Mammals that spend time underwater like seals and dugongs have nostrils at the tip of their snouts.
When they want to breathe, they push their nostrils above the water surface.
But when they are underwater, they keep their nostrils shut to keep water out.
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12. Blowhole
Aquatic mammals like whales and dolphins have blowholes on top of their heads.
This enables them to breathe even when most of the body is underwater – with only the blowhole above the water surface.
Whales and dolphins can also hold their breaths for long periods of time.
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13. Adaptations for movement
Let us take a look at how animals adapt to moving in water and in air.
Movement is important for animals so that they can hunt for food and escape from danger.
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14. Moving in water
Movement in water involves a force that acts against the direction of this movement.
Aquatic animals need to overcome this force so that they can move easily through water.
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15. Streamlined body shape
The bodies of most aquatic animals are streamlined.
A streamlined body shape is one that is narrow at both ends, and broad in the middle.
This shape allows the animals to move quickly through water.
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16. Modified limbs
Most aquatic animals have modified limbs to help them move in water.
Fins keep a fish balanced
and its powerful tail propels
it forward.
Animals like seals have flippers for paddling in water.
Frogs have webbed feet for swimming.
A backswimmer has oar-like legs for swimming.
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17. Swim bladder
Besides being able to swim, aquatic animals need to stay afloat in water.
Most fishes have swim bladders.
The swim bladder is like a little balloon of air inside the body of the fish.
The fish can control the depth it wants to float at by varying the amount of air held in its swim bladder.
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18. Moving in air
Some animals such as bats, insects and birds are able to fly in the air.
Flying allows them to escape from danger quickly, and swoop down on a distant prey.
All flying animals have wings.
Unlike insects and bats which are small and require less effort to fly, birds, which can be large, have special adaptations for flight.
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19. Wings Birds have wings that are well developed for flying.
Bird that have heavy bodies and less developed wings cannot fly.
These include the ostrich, emu, goose, chicken and turkey.
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20. Flight muscles
Birds also have strong flight muscles for flapping their wings.
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21. Feathers Birds are the only animals that have feathers.
Feathers make light but strong wings, and also keep birds warm.
The warmth provided by the feathers makes sure that the flight muscles can work properly.
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22. Streamlined body shape
Just like in water, there is a force that opposes motion in air.
When a bird is flying, its streamlined body shape helps it to overcome this come.
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23. Hollow bones Bird have strong but hollow bones.
This is important as this reduces the bird’s body weight and makes flight easier.
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24. Adaptations for catching prey
All predators have adaptations that allow
them to hunt for food.
For example,
Sharks have a strong sense of smell and are generally able to detect as little one part of per million of blood in seawater. This makes it easy for sharks to find their prey.
Sharp teeth is also one of the most visible adaptations on many animals. Sharp teeth helps an animal eat meat. Found primarily on meat-eating animals, or carnivores, sharp teeth are used mainly for tearing and chewing of an animal’s prey.
Other adaptations for catching prey include strong jaws, claws, sticky tongue, super senses and speed.
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25. Adaptations for obtaining sunlight
So these plants have special adaptations for their leaves to get sunlight. Such plants can be grouped as creepers or climbers.
Most land plants and trees have strong, woody stems to hold up their branches and leaves to get enough sunlight.
Plants need to get enough sunlight in order to carry out photosynthesis.
Other plants, however, have soft, non-woody stems and cannot grow upright.
So how do plants get sunlight?
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26. How land plants get sunlight
Creepers
Creepers grow horizontally on the ground.
Their shoots spread out on all sides of the main stem.
Carpet grass and mimosa are examples of creepers.
carpet grass
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27. How land plants get sunlight
Climbers
Climbers climb onto supports such as walls, fences or other plants that have strong stems.
Some climbers have tendrils or clasping roots to attach themselves to the supports.
tendril of a passion fruit vine coiling around a branch
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28. How aquatic plants get sunlight
Sunlight cannot reach deep into water. The deeper the water is, the less sunlight is available.
Thus, to get enough sunlight, many aquatic plants adapt by floating or sticking their leaves out of the water surface.
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29. How aquatic plants get sunlight
The water lily and lotus have large waxy leaves.
This prevents water from collecting on the leaves.
When leaves collect water, they will sink beneath the water surface.
waxy leaf
lotus
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30. How aquatic plants get sunlight
Aquatic plants also have air spaces in their leaves and stems.
These air spaces keep the plant upright in the water to get more sunlight.
The leaves of the water spangle and water moss fern have hairs that trap air.
swollen leaf stalk in the water hyacinth contains air
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31. Adaptations for coping with extreme temperatures
Living in a cold environment
white coat
In the North and South Poles, it is cold all year round.
What adaptations do the plants and animals living here need to survive?
thick fur and an extra layer of fat
soles covered with stiff hairs
polar bear
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32. Adaptations for coping with extreme temperatures
Living in a cold environment
closely-packed feathers
penguin
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33. Adaptations for coping with extreme temperatures
Living in a cold environment
a thick layer of fat called blubber
walrus
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34. Adaptations for coping with extreme temperatures
Living in a cold environment
Some plants in cold places, such as lichens and some grasses, grow in clumps close to the ground.
This adaptation protects them from the freezing winds.
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35. Adaptations for coping with extreme temperatures
Living in a hot environment
A camel can drink more than 100 litres of water at one time.
This allows it to go for a long distance without water.
It also sweats and urinates very little to retain as much water as possible.
A camel’s hump stores fat that releases energy for the animal.
It is very hot and dry in a desert habitat. How do living things survive in a desert?
camel
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36. Adaptations for coping with extreme temperatures
Living in a hot environment
Some animals avoid the Sun’s heat by staying underground or in the shade during the day.
At night, when it is cooler, they come out to hunt for food.
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37. Adaptations for protection
Body coverings
Body coverings are adaptations to help animals survive in their environment.
Some body coverings are used to protect the animals against the temperatures of their environment.
Others are used to protect the animals from their predators.
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38. Feathers Feathers keep birds warm and help them to fly.
Some birds have to dive or swim in water to find food.
These birds have feathers which are covered with a layer of oil that makes the feathers waterproof and helps the bird to float.
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39. Fur Some animals have a coat of thick, soft hair called fur.
In a very cold environment, the thick fur traps air close to the animal’s body.
This layer of air insulates the animal from the cold and keeps the animal’s body at a constant temperature.
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40. Scales, shells and spines
Reptiles and most fishes have scales, which can be smooth, rough or pointed.
fish scales
scales on a snake
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41. Scales, shells and spines
Other animals like turtles, snails and crabs have shells to cover their bodies.
snail
turtle
crab
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42. Scales, shells and spines
Hedgehogs, spiny anteaters and porcupinefish have spines.
Scales, shells and spines are hard and not easily broken.
So they act like armour to protect the animals from their enemies.
spiny anteater
This is very useful for animals that move too slowly to escape from danger.
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43. Camouflage
Some animals cannot be easily spotted because they blend in with their surroundings.
This is an adaptation called camouflage.
Camouflage gives animals a better chance of survival as they are less likely to be eaten by their predators and more likely to catch their prey.
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44. Camouflage
An example of camouflage is that the fur and feathers of some animals can change colour at different times of the year.
The fur or feathers can be white during the winter months and in shades of brown in the summer months.
This adaptation allows the animal to blend in with its different surroundings during different seasons.
Examples of these animals are arctic foxes and arctic hares.
arctic fox
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45. Camouflage
Other animals such as the leaf insect and stick insect have body shapes and colours that blend into their surroundings.
leaf insect
stick insect
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46. Camouflage
Some animals have patterns that look like big eyes on their bodies.
These are called ‘eyespots’.
Predators may mistake these eyespots as belonging to that of larger creatures.
As a result, the predators move away, thinking they may become prey themselves.
moth
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47. Adaptations for reproduction
Animals have to mate in order to reproduce. Before they can mate, they have to find a mate or sexual partner.
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48. Reproduction in animals – finding mates
Body covering
Many animals have specialised ways of attracting their mates.
The males often have more colourful body coverings than the males, which makes them more attractive to the females who are looking for mates.
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49. Reproduction in animals – finding mates
Body covering
The male peacock has a spectacular way of attracting a female.
It spreads out its tail feathers in a big, colourful fan.
After the mating season, the male peacock’s tail feathers are no longer needed and they drop off.
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50. Reproduction in animals – finding mates
Behaviour
The male frigate bird has an inflatable red throat sac.
It puffs the throat sac like a huge balloon for long hours.
It also vibrates the throat sac, claps its bill and waves its wings to attract a female.
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51. Reproduction in animals – finding mates
Lighting up
Animals that live in very dark places glow in the dark to attract their mates.
E.g. glow-worms
Wingless females of a type of beetle
The tip of the female’s abdomen glows in the dark to attract the flying males to mate with her.
glow worm
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52. Reproduction in animals – finding mates
Lighting up
Fishes living in deep sea, where it is very dark, have parts of their bodies that light up to attract mates.
anglerfish
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53. Reproduction in plants – getting the flowers pollinated
Flowering plants need to be pollinated in order to reproduce.
During pollination, some flowering plants depend on the wind to disperse their pollen grains.
Most of them, however, depend on animals like insects or birds.
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54. Reproduction in plants – getting the flowers pollinated
Adaptations of plants for pollination
Flowers that are pollinated by insects and birds are usually large and colourful.
They have nectar and a fragrance so that the animals are attracted to them.
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55. Reproduction in plants – getting the flowers pollinated
Adaptations of plants for pollination
Flowers that are pollinated by wind are usually small and plain.
They are without fragrance as they do not need to attract animals.
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56. Reproduction in plants – getting the seeds dispersed
Flowering plants have different adaptations to allow their seeds to be dispersed as far away as possible.
Dispersal methods:
By water
By explosion
By wind
tomato
By animals
coconut
saga
love grass
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57. The end
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