1. Living Things and Their Needs
environment
biome
climate
soil
humus
structure
shelter
Start with the CALIFORNIA STANDARDS
3 LS 3.a. Students know plants and animals have structures that serve different functions in growth, survival, and reproduction.
3 LS 3.b. Students know examples of diverse life forms in different environments, such as oceans, deserts, tundra, forests, grasslands, and wetlands.
Look and Wonder
Invite students to share responses to the Look and Wonder question:
■ How do living things get what they need to survive?
Have students identify structures and behaviors that help organisms meet their needs. Make notes of possible misconceptions.
adaptation
Living Things and Their Needs

2. Where do living things live?
environment (en vī´rən mənt) All the living and nonliving things that surround a living thing.
Where do living things live?
climate
environment
biome
soil
humus
biome (bī´ōm) An area of land or water that has certain kinds of living and nonliving things.
climate (clī´mit) The average weather patterns of a region.
Start with the CALIFORNIA STANDARDS
3 LS 3.a. Students know plants and animals have structures that serve different functions in growth, survival, and reproduction.
3 LS 3.b. Students know examples of diverse life forms in different environments, such as oceans, deserts, tundra, forests, grasslands, and wetlands.
Main Idea
Living things get what they need from their environment.
Discuss the Main Idea
Have students identify and describe characteristics of the environment within the immediate geographic area. Ask:
■ How is the biome in this area most like a desert, forest, or grassland?
Possible answers: hot, cold, wet, dry, sunny, cloudy, sandy soil, rich soil, presence of cacti, grass fields, tall trees, reptiles, deer.
■ Why do you think that few trees grow in a desert biome?
Most trees need good soil and a lot of water. Deserts have little water and poor soil.
Use the Visuals
Have students examine the pictures on pages 26 and 27. Ask:
■ How are desert and grassland biomes different?
Possible answers: The desert is sandy while the grassland is covered with grass. The desert supports camels while the grassland supports bison, or buffalo. The desert has sandy soil while the grassland has richer soil that contains more humus. The grassland receives more rainfall than the desert. This desert is hotter than the grassland.
■ Why do bison, or buffalo, live in a grassland biome rather than a desert biome?
Possible answers: A grassland biome provides food lacking in a desert; a desert biome does not have enough water for bison, a desert biome is too hot for a bison.
Develop Vocabulary
environment (en vī′rәn mәnt) All the living and nonliving things that surround a living thing. (p. 26)
Plants need an environment in which they can get sunlight, water, carbon dioxide, and other nutrients.
- Word Origin The word environment comes from the Old French word environ, meaning “to surround or encircle.”
biome (bī′ōm) An area of land or water that has certain kinds of living and nonliving things. (p. 26)
A desert biome is very different from an ocean biome.
- Word Origin The word biome comes from the Greek root bios, meaning “life,” coupled with the Latin oma, meaning “group or mass.”
climate (klī′mit) The average weather patterns of a region. (p. 27)
Most people prefer a warm climate.
- Word Origin The word climate comes from the Old French word climat, originally meaning “region or slope of the earth.” The meaning shifted from “region” to “weather associated with that region” by the year 1600.
soil (soil) A mixture of tiny rock particles, minerals, and decayed plant and animal matter. (p. 27)
Every biome has a certain kind of soil.
- Word Origin The word soil comes from the Latin word solum, meaning “floor, ground, or dirt.”
humus (hū′mәs) Leftover decomposed plant or animal material in soil. (p. 27)
Each layer of soil has different amounts of rock and humus.
- Word Origin The word humus most probably comes from the Latin word humi, meaning “on the ground.”
Critical Thinking
What are some of the living things in a city environment?
Possible answers: people, pigeons, dogs, cats, squirrels, trees, flowers.
soil (soil) A mixture of tiny rock particles, minerals, and decayed plant and animal matter.
humus (hū´məs) Leftover decomposed plant or animal material in soil.

3. Biomes
Start with the CALIFORNIA STANDARDS
3 LS 3.a. Students know plants and animals have structures that serve different functions in growth, survival, and reproduction.
3 LS 3.b. Students know examples of diverse life forms in different environments, such as oceans, deserts, tundra, forests, grasslands, and wetlands.
Use the Visuals
Have students examine the pictures on pages 26 and 27. Ask:
■ How are desert and grassland biomes different?
Possible answers: The desert is sandy while the grassland is covered with grass. The desert supports camels while the grassland supports bison, or buffalo. The desert has sandy soil while the grassland has richer soil that contains more humus. The grassland receives more rainfall than the desert. This desert is hotter than the grassland.
■ Why do bison, or buffalo, live in a grassland biome rather than a desert biome?
Possible answers: A grassland biome provides food lacking in a desert; a desert biome does not have enough water for bison, a desert biome is too hot for a bison.
This camel lives in a desert. Deserts are biomes that have dry climates and sandy soil. Deserts can be hot or cold.

4. How do plants get what they need?
structure
stems
Start with the CALIFORNIA STANDARDS
3 LS 3.a. Students know plants and animals have structures that serve different functions in growth, survival, and reproduction.
3 LS 3.b. Students know examples of diverse life forms in different environments, such as oceans, deserts, tundra, forests, grasslands, and wetlands.
Discuss the Main Idea
Have students identify, compare, and contrast plant structures that receive needed substances from the soil and from the air. Ask:
■ How does water travel from plant roots to reach the leaves?
Water taken in by roots is carried through the stems to the leaves.
■ Why will a plant die if all of its leaves are removed during the growing season?
The Sun’s energy shines on leaves and changes carbon dioxide and water into food for the plant. The plant will not have food if the leaves are removed during the growing season.
Read a Diagram
How do leaves help plants get what they need?
Clue: Bold words can help you find information.
Answer Leaves take in carbon dioxide from the air and use energy from the Sun to make food needed by plants.
Develop Vocabulary
structure (strәk′chәr) A thing that is developed or built for a particular use. (p. 29)
Fish have structures called gills to help them breathe in the ocean.
- Word Origin The word structure comes from the Latin word structura, meaning “a fitting together, to build, or to assemble.”
Critical Thinking
Why don’t plants need to eat?
Answer: Plants do not need to eat because they are able to make their own food.
structure (strək´chər) A thing that is developed or built for a particular use.
leaves
roots

5. How do animals get what they need?
shelter
gills
Start with the CALIFORNIA STANDARDS
3 LS 3.a. Students know plants and animals have structures that serve different functions in growth, survival, and reproduction.
3 LS 3.b. Students know examples of diverse life forms in different environments, such as oceans, deserts, tundra, forests, grasslands, and wetlands.
Discuss the Main Idea
Have students contrast plant needs with animal needs. List differences on the board and discuss ways that animals meet their needs. Ask:
■ What do plants and animals both need?
water, energy from food, and oxygen
■ How can animals use their structures to meet their needs?
Possible answers: move to find food and water; catch food; swallow food and water; breathe or get oxygen from the air or water; build shelters; escape or protect themselves from danger.
Use the Visuals
Have students look at the photos on page 30.
■ How does a lion’s tongue help it get water?
The rough surface holds on to some of the water and does not let it run off the tongue quickly. Some of the water is drawn into the mouth and swallowed as the lion laps at the liquid.
■ How do birds use their nests as shelter?
Possible answers: place to rest; place to lay eggs; place to raise young; place away from animals that might harm or eat them, their eggs, or their young.
■What structures do young turtles use to help them stay safe since they do not stay with their mothers the way young kangaroos do?
Turtles have a hard shell to protect their soft body parts.
■Why do you see fish in an aquarium opening and closing their gills?
to push water through their gills and take in oxygen from the water
Develop Vocabulary
shelter (shel′tәr) A place or object that protects an animal and keeps it safe.(p. 30)
During a rainstorm, you might seek shelter under a tree.
- Word Origin The word shelter is thought to come from the Middle English word sheltron, meaning “roof or wall formed by locked shields.” The notion is of a compact body of men protected by interlocking shields.
Critical Thinking
How might the shape of a bird’s beak affect what it eats?
Possible answers: A bird that has a small beak might eat berries and insects. A bird that has a large beak like a pelican’s might scoop fish from the water. A bird that has a sharp, strong beak might eat small animals.
shelter (shel´tər) A place or object that protects an animal and keeps it safe.

6. What helps living things survive in their environments?
adaptation
adaptation (a´dap´tā´shən) A special trait that helps a living thing survive in its environment.
Start with the CALIFORNIA STANDARDS
3 LS 3.a. Students know plants and animals have structures that serve different functions in growth, survival, and reproduction.
3 LS 3.b. Students know examples of diverse life forms in different environments, such as oceans, deserts, tundra, forests, grasslands, and wetlands.
Discuss the Main Idea
Have students identify adaptations evident in pet dogs and cats. As you write ideas on the board, encourage students to compare and contrast how identified adaptations help the pets. Ask:
■ What adaptation helps dogs and cats survive in colder environments?
fur or hair
■ How is an adaptation like claws different from an adaptation like hunting?
Living things are born with physical features like claws. Living things learn behaviors like hunting.
Use the Visuals
Have students look at the picture on page 32.
■ What other adaptations help a bear catch fish?
Possible answers: sharp teeth, powerful body, quick movement.
Develop Vocabulary
adaptation (a′dap′tā′shәn) A special trait that helps a living thing survive in its environment. (p. 32)
A fish’s gills are an example of adaptation.
- Word Origin The word adaptation comes from the Latin word adaptare, meaning “adjust.”
Critical Thinking
Are a bear’s sharp teeth an adaptation?
Answers: A bear’s sharp teeth are an adaptation. Sharp teeth are structures that help the bear survive.

7. What are adaptations and how do they help living things survive?
Review
Main Idea
What are adaptations and how do they help living things survive?
An adaptation is a special feature or behavior that helps a living thing survive. This bear’s claws are an adaptation that help it catch fish.
Start with the CALIFORNIA STANDARDS
3 LS 3.a. Students know plants and animals have structures that serve different functions in growth, survival, and reproduction.
3 LS 3.b. Students know examples of diverse life forms in different environments, such as oceans, deserts, tundra, forests, grasslands, and wetlands.
Answer:
An adaptation is a special feature or behavior that helps a living thing survive. This bear’s claws are an adaptation that help it catch fish.

8. How do living things get what they need from their environments?
Review
Main Idea
How do living things get what they need from their environments?
Living things have structures that help them get what they need from their environments.
Start with the CALIFORNIA STANDARDS
3 LS 3.a. Students know plants and animals have structures that serve different functions in growth, survival, and reproduction.
3 LS 3.b. Students know examples of diverse life forms in different environments, such as oceans, deserts, tundra, forests, grasslands, and wetlands.
Main Idea:
Living things have structures that help them get what they need from their environment.

9. Text Clues Conclusions
Review
Draw Conclusions
Could a redwood tree survive in the desert?
Text Clues
Conclusions
Redwoods grow along the California coast.
Redwoods are normally found along the coast.
Box 1: Redwoods grow along the California coast.
Box 2: Redwoods are normally found along the coast.
Box 3: Here the cool, damp climate and rich soil are just right for them to grow.
Box 4: The desert’s warm, dry climate and sandy soil will not allow the redwood tree to survive in the desert.
Alternate Questions
Draw Conclusions: Do all deserts have similar kinds of living things?
Conclusion: All deserts have similar kinds of living things.
Draw Conclusions Why are roots important to plants?
Conclusion: Roots are important because they take in the water and nutrients that plants need to grow.
Draw Conclusions Why are legs, fins, and wings important to some animals?
Conclusion: Animals must find and get food to eat. Legs, fins, and wings are structures that help animals move so they can find food, water, and shelter.
Draw Conclusions Why can’t a cactus grow where redwoods grow?
Conclusion: A cactus cannot grow where redwoods grow because a cactus needs dry conditions and sandy soil.
Draw Conclusions Some soil has very little humus. Would this kind of soil soak up a lot of water or a little?
Conclusion: Soil with little humus would soak up little water.
Here the cool, damp climate and rich soil are just right for them to grow.
The desert’s warm, dry climate and sandy soil will not allow the redwood tree to survive in the desert.

10. Match each word with its definition.
Review
Vocabulary
Match each word with its definition.
biome
climate
environment
humus A)
the average weather patterns of a region
Vocabulary
A= climate
B= humus
C= biome
D= environment
Develop Vocabulary
environment (en vī′rәn mәnt) All the living and nonliving things that surround a living thing. (p. 26)
Plants need an environment in which they can get sunlight, water, carbon dioxide, and other nutrients.
biome (bī′ōm) An area of land or water that has certain kinds of living and nonliving things. (p. 26)
A desert biome is very different from an ocean biome.
climate (klī′mit) The average weather patterns of a region. (p. 27)
Most people prefer a warm climate.
soil (soil) A mixture of tiny rock particles, minerals, and decayed plant and animal matter. (p. 27)
Every biome has a certain kind of soil.
humus (hū′mәs) Leftover decomposed plant or animal material in soil. (p. 27)
Each layer of soil has different amounts of rock and humus.
structure (strәk′chәr) A thing that is developed or built for a particular use. (p. 29)
Fish have structures called gills to help them breathe in the ocean.
shelter (shel′tәr) A place or object that protects an animal and keeps it safe.(p. 30)
During a rainstorm, you might seek shelter under a tree.
adaptation (aªdapªtā′shәn) A special trait that helps a living thing survive in its environment. (p. 32)
A fish’s gills are an example of adaptation. B)
broken-down plant and animal material C)
an area of land or water that has certain kinds of living and nonliving things D)
everything that surrounds a living thing

11. Match each word with its definition.
Review
Vocabulary
Match each word with its definition.
soil
shelter
adaptation
structure A)
a place or object that protects an animal and keeps it safe
Vocabulary
A= shelter
B= structure
C= soil
D= adaptation
Develop Vocabulary
environment (en vī′rәn mәnt) All the living and nonliving things that surround a living thing. (p. 26)
Plants need an environment in which they can get sunlight, water, carbon dioxide, and other nutrients.
biome (bī′ōm) An area of land or water that has certain kinds of living and nonliving things. (p. 26)
A desert biome is very different from an ocean biome.
climate (klī′mit) The average weather patterns of a region. (p. 27)
Most people prefer a warm climate.
soil (soil) A mixture of tiny rock particles, minerals, and decayed plant and animal matter. (p. 27)
Every biome has a certain kind of soil.
humus (hū′mәs) Leftover decomposed plant or animal material in soil. (p. 27)
Each layer of soil has different amounts of rock and humus.
structure (strәk′chәr) A thing that is developed or built for a particular use. (p. 29)
Fish have structures called gills to help them breathe in the ocean.
shelter (shel′tәr) A place or object that protects an animal and keeps it safe.(p. 30)
During a rainstorm, you might seek shelter under a tree.
adaptation (aªdapªtā′shәn) A special trait that helps a living thing survive in its environment. (p. 32)
A fish’s gills are an example of adaptation. B)
a thing that is developed or built for a particular use C)
a mixture of tiny rock particles, minerals, and decayed plant and animal matter D)
a special trait that helps a living thing survive in its environment

12. How do leaves help plants get what they need?
Review
Read a Diagram
How do leaves help plants get what they need?
Read a Diagram
How do leaves help plants get what they need?
Clue: Bold words can help you find information.
Answer: Answer Leaves take in carbon dioxide from the air and use energy from the Sun to make food needed by plants.

13. Click on the diagrams to open enlarged editable version.