2009 Marshall Cavendish International Singapore Private Limited Questions

© 2009 Marshall Cavendish International (Singapore) Private Limited

Questions to think about… What are the types of adaptations? How do adaptations improve chances of survival? © 2009 Marshall Cavendish International (Singapore) Private Limited

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 o cope with physical conditions such as temperature and light o protect themselves from their enemies o reproduce o © 2009 Marshall Cavendish International (Singapore) Private Limited

Adaptations • Special characteristics that help organisms survive in their natural habitats are called adaptations. Adaptations structural special body parts of an organism that help it to survive in its natural habitat, for example, its colour, shape and body covering behavioural special ways an organism behaves to survive in its natural habitat © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

Gill chambers • There 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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

Modified limbs • Most aquatic animals have modified limbs to help them move in water. Fins keep a fish balanced have and its Animals powerfullike tail seals propels flippers for paddling in it forward. water. Frogs A have webbed has oar-like backswimmer feet forlegs swimming. for swimming. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

Flight muscles • Birds also have strong flight muscles for flapping their wings. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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 force. © 2009 Marshall Cavendish International (Singapore) Private Limited

Hollow bones • Bird have strong but hollow bones. • This is important as this reduces the bird’s body weight and makes flight easier. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

Adaptations for obtaining sunlight Soland these plants have Most plants and trees Plants need tohowever, get enough Other plants, special adaptations for their have strong, woody stems sunlight in non-woody order to carry have soft, leaves toup get sunlight. Such to hold their branches out photosynthesis. stems andgrouped cannot as plants can be and leaves toupright. get enough grow creepers or climbers. sunlight. So how do plants get sunlight? © 2009 Marshall Cavendish International (Singapore) Private Limited

How land plants get sunlight • Creepers grow horizontally on the ground. o Their shoots spread out on all sides of the main stem. o Carpet grass and mimosa are examples of creepers. o carpet grass © 2009 Marshall Cavendish International (Singapore) Private Limited

How land plants get sunlight • Climbers climb onto supports such as walls, fences or other plants that have strong stems. o Some climbers have tendrils or clasping roots to attach themselves to the supports. o tendril of a passion fruit vine coiling around a branch © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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 © 2009 Marshall Cavendish International (Singapore) Private Limited

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 © 2009 Marshall Cavendish International (Singapore) Private Limited

Adaptations for coping with extreme temperatures • Living in a cold environment white coat thick fur and an extra layer of fat soles covered with stiff hairs polar bear © 2009 Marshall Cavendish International (Singapore) Private Limited

Adaptations for coping with extreme temperatures • Living in a cold environment closely-packed feathers penguin © 2009 Marshall Cavendish International (Singapore) Private Limited

Adaptations for coping with extreme temperatures • Living in a cold environment a thick layer of fat called blubber walrus © 2009 Marshall Cavendish International (Singapore) Private Limited

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. o This adaptation protects them from the freezing winds. o © 2009 Marshall Cavendish International (Singapore) Private Limited

Adaptations for coping with extreme temperatures • Living in a hot environment A camel can drink more than 100 litres of water at one time. o This allows it to go for a long distance without water. o It also sweats and urinates very little to retain as much water as possible. o A camel’s hump stores fat that releases energy for the animal. o camel © 2009 Marshall Cavendish International (Singapore) Private Limited

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. o At night, when it is cooler, they come out to hunt for food. o © 2009 Marshall Cavendish International (Singapore) Private Limited

Adaptations for protection • Body coverings are adaptations to help animals survive in their environment. o Some body coverings are used to protect the animals against the temperatures of their environment. o Others are used to protect the animals from their predators. o © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

Scales, shells and spines • Reptiles and most fishes have scales, which can be smooth, rough or pointed. fish scales on a snake © 2009 Marshall Cavendish International (Singapore) Private Limited

Scales, shells and spines • Other animals like turtles, snails and crabs have shells to cover their bodies. snail crab turtle © 2009 Marshall Cavendish International (Singapore) Private Limited

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. • This is very useful for animals that move too slowly to escape from danger. spiny anteater © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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 © 2009 Marshall Cavendish International (Singapore) Private Limited

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 © 2009 Marshall Cavendish International (Singapore) Private Limited

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 © 2009 Marshall Cavendish International (Singapore) Private Limited

Adaptations for reproduction Animals have to mate in order to reproduce. Before they can mate, they have to find a mate or sexual partner. © 2009 Marshall Cavendish International (Singapore) Private Limited

Reproduction in animals – finding mates • Body covering Many animals have specialised ways of attracting their mates. o The males often have more colourful body coverings than the females, which makes them more attractive to the females who are looking for mates. o © 2009 Marshall Cavendish International (Singapore) Private Limited

Reproduction in animals – finding mates • Body covering The male peacock has a spectacular way of attracting a female. o It spreads out its tail feathers in a big, colourful fan. o After the mating season, the male peacock’s tail feathers are no longer needed and they drop off. o © 2009 Marshall Cavendish International (Singapore) Private Limited

Reproduction in animals – finding mates • Behaviour The male frigate bird has an inflatable red throat sac. o It puffs the throat sac like a huge balloon for long hours. o It also vibrates the throat sac, claps its bill and waves its wings to attract a female. o © 2009 Marshall Cavendish International (Singapore) Private Limited

Reproduction in animals – finding mates • Lighting up Animals that live in very dark places glow in the dark to attract their mates. o E. g. glow-worms o • 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 © 2009 Marshall Cavendish International (Singapore) Private Limited

Reproduction in animals – finding mates • Lighting up o Fishes living in deep sea, where it is very dark, have parts of their bodies that light up to attract mates. anglerfish © 2009 Marshall Cavendish International (Singapore) Private Limited

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. © 2009 Marshall Cavendish International (Singapore) Private Limited

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. o They have nectar and a fragrance so that the animals are attracted to them. o © 2009 Marshall Cavendish International (Singapore) Private Limited

Reproduction in plants – getting the flowers pollinated • Adaptations of plants for pollination Flowers that are pollinated by wind are usually small and plain. o They are without fragrance as they do not need to attract animals. o © 2009 Marshall Cavendish International (Singapore) Private Limited

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: tomato coconut saga love grass © 2009 Marshall Cavendish International (Singapore) Private Limited

© 2009 Marshall Cavendish International (Singapore) Private Limited