Download LESSON 27 TEKS: 3.10A, 4.10A, 5.10A,B Adaptations The words in

LESSON 27
TEKS: 3.10A, 4.10A, 5.10A,B
Adaptations
The words in bold are vocabulary words that the student should be aware of.
To survive, plants and animals must have ways to meet their basic needs. Any feature that
helps a living thing survive in its environment is an adaptation. Some adaptations are body
parts, such as webbed feet or sharp teeth. Other adaptations are behaviors, or ways an animal
acts, such as hibernating or a squirrel storing food for the winter.
Each living thing is born with its adaptations. Adaptations do not develop or change during a
living thing’s lifetime. But plants and animals that are best suited to the places where they live
are most likely to survive and reproduce.
Adaptations in Land Environments
Tropical rain forests are warm and wet. Plants in a rain forest have plenty of water. But trees
and other plants grow so close together that they block the sunlight. Remember that plants
need sunlight to make their own food. Many rain forest trees have very long
trunks to help them reach the sunlight. Rain forest plants also have wide, flat
leaves. These leaves help them to absorb as much sunlight as possible.
Many animals in tropical rain forests have adaptations for living in tall trees.
Howler monkeys have tails that can grab onto branches. A howler monkey
holds on with its tail at all times.
Sloths have long, curved claws that let them hang from tree
branches. Sloths also use their claws to protect themselves from
attackers. Howler monkeys and sloths eat mainly leaves, so they
can find food without leaving the trees. The leaves also contain
most of the water the animals need.
The armadillo has a tough
leathery skin that helps protect it from predators. It also has
strong claws that it uses for digging to get food and for
burrowing to find shelter. The armadillo also has the ability
to gulp air to inflate its digestive tract. The inflated digestive
tract allows the animal to swim across streams.
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What is an adaptation? __________________________________________________
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In deserts, water is scarce. Desert plants and animals have adaptations that
help them survive without much water. Cactuses have roots that spread out
near the surface. When rain falls, the roots soak up water quickly before it can
dry up in the hot, dry air. Cactuses store the water in their thick stems. Some
other desert plants, such as mesquite trees, have very long roots. The roots
reach down to water far below the surface.
Plants lose water through their leaves, in a process called transpiration. Desert plants can
conserve water by having very small leaves. Cactus plants have such small leaves that you can
see them only with a microscope. Mesquite trees have small leaves with a way coating. The
coating helps keep the leaves from losing water. Cactuses and many other desert plants have
sharp spines. Spines help protect the plants from animals that would use them as sources of
food and water.
Desert animals also have adaptations that help them save water.
Many lizards and snakes live in deserts. Lizards and snakes have
scales. The scales help keep the animals from losing water through
their skin. Many desert animals are active at night, when the air is
cool. They sleep during the day in places sheltered from the hot sun.
The Arctic tundra in the northern polar region also gets very little rain. The tundra is very cold.
Temperatures there can get as cold as -50⁰F. Plants in the tundra can grow for only a short
time each year. The plants best suited for this environment are mosses, lichens, and grasses.
The polar bear has a number of adaptations that help it survive
in this cold ecosystem. It has thick fur that provides warmth and
camouflage. It also has a layer of body fat under its skin that can
be as much as 4.5 inches thick. The hairs of a polar bear’s thick
fur are actually clear, not white. They allow the sunlight to reach
the bear’s dark skin to help keep the polar bear warm.
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What adaptations help a polar bear survive?
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What 2 adaptations do cactus plants have that help them survive in the desert?
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How do scales help lizards and snakes that live in the desert?
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Adaptations in Water Environments
There are two main types of water environments – salt water and freshwater. The oceans
contain most of the salt water. Rivers and streams contain freshwater– water that is not salty.
Lakes, ponds, and many wetlands also contain freshwater. Just as on land, plants and animals
have adaptations for different water environments.
In the ocean, algae are important producers. Algae are a kind of plankton. Most plankton are
tiny organisms that float in the water. Algae and certain other kinds of plankton use sunlight to
make their own food. They float near the surface of the ocean where sunlight can reach them.
The shapes of large ocean animals are also adaptations for living in water. Both whales and fish
have bodies that are narrower in the front and back and wider in the middle. This shape lets
them move smoothly and quickly through water. A whale’s smooth skin and a fish’s slippery
scales help them glide through the water. A whale uses its flippers to steer and turn, and a fish
uses its fins in the same way.
However, whales and fish have different adaptations for breathing in water. Whales are
mammals that breathe air. They come up to the surface and breathe through the blowholes on
top of their heads. Fish take in water through their gills and get the gases they need from the
water.
Like plant life in salt water, freshwater plants need sunlight to make food.
They have adaptations for getting enough sunlight. Water lilies grow in
rivers and lakes. Their roots grow down into the soil at the bottom. Their
long stems reach up, and their wide leaves float on the water’s surface.
Their leaves gather the sunlight that is necessary for photosynthesis.
Like saltwater fish, freshwater fish have narrow bodies and fins for
swimming. They also have gills for breathing underwater. Frogs and
ducks have webbed feet that help them swim in lakes and rivers.
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How does the shape of the whale and the fish help it to survive in the water?
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Other Adaptations
Camouflage is a pattern or coloring that helps a living thing blend in with its surroundings. A
plant or animal that is difficult to see is less likely to be eaten. For example, green tree frogs
blend in with the thick green leaves of rain forests. Arctic hares have white fur that blends in
with their snowy environment. Camouflage also helps some animals find food. A polar bear’s
white fur helps it hide while it hunts.
In places where seasons change, animals have adaptations for
winter. As the weather gets colder, it is more difficult to find food.
Then some animals migrate, or move from one place to another.
Geese and monarch butterflies are examples of animals that
migrate.
Some other animals spend the fall months
eating as much food as they can. Then they
hibernate, or go into a sleep – like state during
winter. When an animal hibernates, its heart
beats very slowly. The temperature of its body
drops. A hibernating animal uses so little energy
that it does not need to eat. It can live off the
fat stored in its body until spring. Some animals
that hibernate are gophers, bats, frogs, snakes,
and ladybugs.
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How is camouflage helpful to an animal?
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How can an animals’ coloring help protect it from predators?
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Why is it helpful for some animals to migrate?
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How is hibernation helpful to an animal?
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QUESTIONS
1. Penguins have webbed
feet. In which kind of
environment would this
feature help a penguin
survive?
A. Ocean
B. Desert
C. Forest
D. Tundra
2. Which animal most likely
lives in a cold place?
A. A fox with thick fur
B. A frog that is green
C. A rat with little fat
D. A coyote that sleeps
during the day
3. Which adaptation helps
some plants that live in dry
deserts?
A. Tall trunks
B. Long roots
C. Thin stems
D. Floating leaves
4. An animal that sleeps
during the day most likely
lives in
A. A tropical rain forest
B. A tundra region
C. A tide pool
D. A hot desert
5. Which of these is not an
adaptation for a polar
bear?
A. Dark skin
B. Front
paws
for
swimming
C. Thick layer of body fat
D. Gills for living and
breathing under water
6. Which adaptation would
best help an owl catch a
mouse?
A. Camouflage
B. Hollow bones
C. Talons or claws
D. Pointed ears
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