1. How do scientists classify Earth’s living things?

2. respond to the environment
What are living things?
Living things:
are made of cells
obtain and use energy
reproduce
grow and develop
respond to the environment
Discuss the Main Idea
Can you classify bicycles by the number of wheels they have? Why?
No. They all have two wheels.
How would you classify bicycles if you owned a bike shop and wanted customers to easily find what they were looking for?
Possible answers: by brand name, size, color, number of gears, or by the type of surface they should be ridden on
Develop Vocabulary
Organism: Word Origin The word organism is derived from the word organ. Tell students that an organism is a living thing that is usually made up of systems of organs.
Use the Visuals
Refer students to the visuals on page 23. Ask:
Why is a rock not considered to be a living thing?
It is not made of cells and does not obtain and use energy, reproduce, grow and develop, or respond to its environment.
The flame of a candle or a fire changes in shape and size, moves, responds to the environment, and uses energy. Is it a living thing? Why or why not?
It is not a living thing, because it is not made of cells and does not reproduce.
How do the subjects in the photos of living things represent living things’ environment?
Possible answer: The subjects in the photos show examples of each of the five basic life functions.
Quick Check (Critical Thinking)
Cars move, age, and use energy. Why are they not living things?
Cars do not meet all five criteria of living things: They do not grow and develop, they are not made of cells, and they do not reproduce.
Lesson 1 a

3. How are organisms classified?
Discuss the Main Idea
What is the difference between kingdoms and species?
A kingdom is the largest, most general grouping. A species is the smallest unit of classification.
What are the advantages of using a classification system to group organisms?
Possible answers: Classifying organisms helps show relationships between organisms. Using a universal classification system helps scientists communicate more easily.
Develop Vocabulary
Species: Word Origin This word in English is identical to the Latin word species, meaning “appearance.” Members of one species have a similar appearance.
Phylum: Word Origin The word phylum is based on the Greek word phylon, meaning “tribe” or “race.”
Kingdom: Scientific vs. Common Use Students will be familiar with the common use of kingdom, used to describe a community with a government headed by a king or queen.
Ask students how the common definition of the word kingdom is related to the scientific definition.
Both kingdoms include a large number of organisms united by certain characteristics
Scientific name: This is the two-word name denoting an organism’s genus and species. The scientific name for modern humans is Homo sapiens.
Quick Check (Critical Thinking)
Which have more in common: organisms in the same family or organisms in the same order? Explain.
Organisms in the same family have more in common. For instance, animals in the family Canidae all look like dogs, whereas animals in the order Carnivora range from bears to foxes.
Lesson 1 b

4. What are some other kingdoms?
Discuss the Main Idea
What are some differences between plants and animals?
Possible answers: Plants can make their own food using sunlight. They use carbon dioxide and give off oxygen. Animals cannot make their own food. Animals use oxygen and give off carbon dioxide. Most animals have some form of locomotion.
What are some examples of fungi? What characteristics do they have?
Possible answers: mushrooms, molds, yeast. They cannot move or make their own food.
Develop Vocabulary
Vascular: Word Origin Explain that the word vascular comes from the Latin word vasculum, meaning “a small vessel.” In animals, vascular tissue consists of small vessels that can carry blood or other body fluids. In plants, the vessels may carry sap or water.
Nonvascular: Have students predict the definition of this word before reading the definition. Remind them that the prefix non- means “not” or “without.”
Quick Check (Critical Thinking)
How are fungi and protists similar to plants and animals? How are they different?
They are similar in that fungi and many protists cannot make their own food. Fungi are different because they do not move. Protists are different because some have chloroplasts, and those protists can make their own food.
Some members of the fungi kingdom cause diseases, but others play a vital role in the environment by breaking down dead organisms.
Lesson 1 c

5. What are bacteria and viruses?
Sphere-shaped eubacteria are called cocci.
influenza virus
Spiral-shaped eubacteria are called spirilla.
Discuss the Main Idea
What are some characteristics of bacteria?
Possible answers: They are single-celled and microscopic. They can cause illness in organisms.
Is a virus considered a living thing? Why or why not?
Answers will vary based on students’ prior knowledge.
Quick Check (Critical Thinking)
If viruses can reproduce inside host cells, why are they not considered living things?
Viruses are not made of cells, do not eat or have a source of energy, cannot reproduce outside of a host cell, and cannot grow.
Rod-shaped eubacteria are called bacillia.
Lesson 1 d

6. Lesson 1 Main Idea Review
How are living things classified?
Living things are grouped by common characteristics. They are placed in one of six kingdoms by general characteristics; more specific characteristics allow them to be grouped in phyla, classes, orders, and families. The genus and species name uniquely describe one type of organisms.
Main Idea
How are living things classified?
Living things are grouped by common characteristics. They are placed in one of six kingdoms by general characteristics; more specific characteristics allow them to be grouped in phyla, classes, orders, and families. The genus and species name uniquely describe one type of organisms.
Lesson 1 Main Idea Review

7. An ______________ is a living thing.
Vocabulary
The largest and most general grouping of living things is a ______________.
An ______________ is a living thing.
The genus and species name of an organism is its ______________.
A ______________ is a group of similar organisms that reproduce more of their own kind.
Vocabulary
Match each word with its definition.
A) The largest and most general grouping of living things is a __________.
B) An _________ is a living thing.
C) The genus and species name of an organism is its __________.
D) A _________ is a group of similar organisms that reproduce more of their own kind.
A-kingdom, B-organism, C-scientific name, D-species
species
scientific name
kingdom
organism
Lesson 1 Vocab a Review

8. An organism is shaped like a plant, does not move, and cannot make its own food. How might you classify it?
Classify
Kingdom
a fungus
Classify
Use graphic organizer 11.
An organism is shaped like a plant, does not move, and cannot make its own food. How might you classify it?
Kingdom: a fungus
Alternate Classify
What are the five characteristics of living things?
Living things are made of cells, obtain and use energy, reproduce, grow and develop, and respond to the environment.
List the seven classification groups in order, beginning with the largest, or most general.
kingdom, phylum, class, order, family, genus, species
What features distinguish each of these kingdoms: plants, fungi, and protists?
Plants are multicellular and can make their own food. Fungi do not move and cannot make their own food. Protists are mostly unicellular and can be either plantlike (able to make their own food) or animal-like (not able to make their own food).
How are eubacteria and archaebacteria classified?
Eubacteria are classified by their shapes. Archaebacteria are classified by where they are found.
End of Lesson
Lesson 1 GO Review

9. Lesson 1 Vocab a

10. Lesson 1 Vocab d

11. Lesson 3

12. What are vertebrates? amphibian reptile mammal bird
Discuss the Main Idea
What is the function of an internal skeleton?
Possible answers: to provide support to the body; to protect organs and tissues.
If an animal has a shell, is it a vertebrate or an invertebrate. Many invertebrates have shells that protect their soft bodies. Some vertebrates, such as turtles, have both shells and endoskeletons.
Develop Vocabulary
Vertebrate: Explain that vertebrates are named for their vertebrae, the segments of the spine.
Chordate: Word Origin The word chordate comes from the Latin word chorda, meaning “cord.” Chordates include both the vertebrates and simple animals with notochords (cartilaginous rods) in place of vertebrae.
Endoskeleton: Word Origin The prefix of this word, endo-, comes from the Greek word endon, meaning “within.” Vertebrates have a skeleton within their bodies.
Cartilage: Remind students that humans are vertebrates and have cartilage in their bodies as well. Cartilage makes up the tip of the nose, the external portion of the ear, and parts of the respiratory system.
Tetrapod: Word Origin The first part of the word tetrapod, tetra, comes from the Greek word tettares, which means “four.” The second part of the word, pod, comes from the Greek word pous, which means “foot.” Tetrapods have four limbs.
Use the Visuals
Refer students to the visuals on page 49. Ask:
What are the groups of vertebrates shown in the pictures?
amphibians, reptiles, birds, and mammals
What are the similarities among the vertebrates in these pictures?
All have an endoskeleton with a backbone and limbs (legs or wings).
Quick Check (Critical Thinking)
Why might there be many more species of bony fish than of fish with cartilage skeletons?
Having a backbone may give bony fish advantages over soft-boned fish that allow them to survive and reproduce more successfully.
A vertebrate is an animal with a segmented backbone.
Lesson 3 a

13. What are invertebrates?
Discuss the Main Idea
How are vertebrates and invertebrates similar and how are they different?
Both are animals. Vertebrates have an internal skeleton, including a backbone. Invertebrates do not have an internal skeleton or a backbone.
Develop Vocabulary
Invertebrate: Word Origin The prefix in- can have multiple meanings. In this usage, in- comes from the Latin prefix un-, which means “not.”
Quick Check (Critical Thinking)
Which types of invertebrates would most likely be seen in your community? Explain.
Answers will vary, depending on the location of your community but should include mollusks, such as snails, or segmented worms, such as earthworms.
Invertebrates are animals without backbones.
Lesson 3 b

14. What are arthropods?
antennae
thorax
jointed legs
head
abdomen
Arthropods are invertebrates with tough exoskeletons that protect their internal organs.
Discuss the Main Idea
What are the characteristics of arthropods?
They have an exoskeleton, a segmented body with specialized sections, and jointed legs.
What characteristics separate the different groups of arthropods from one another?
Possible answers: number of legs; number of body sections; whether or not they have antennae
Develop Vocabulary
Exoskeleton: Word Origin The prefix exo- comes from the Greek word exo, which means “outside.”
Read a Photo
How does an arthropod such as this grasshopper differ from a vertebrate?
An arthropod has an exoskeleton but no backbone or internal skeleton.
Quick Check (Critical Thinking)
“All spiders are arachnids, but not all arachnids are spiders.” Explain this statement.
Arachnids include spiders as well as scorpions, mites, and ticks.
Lesson 3 c

15. A ____________ is an animal with a segmented backbone.
Vocabulary
A ____________ is an animal with a segmented backbone.
____________ is soft bonelike material that grows with the animal.
An inner skeleton for protection and movement is an ____________.
A ____________ is an animal with nerve cords in place of vertebrae.
Cartilage
Vocabulary
Match each word with its definition
A) A __________ is an animal with a segmented backbone.
B) __________ is soft bonelike material that grows with the animal.
C) An inner skeleton for protection and movement is an __________.
D) A __________ is animal with nerve cords in place of vertebrae.
A-vertebrate, B-cartilage, C-endoskeleton, D-chordate
vertebrate
chordate
endoskeleton
cartilage
Lesson 3 Vocab a Review

16. An animal without a backbone is an ____________.
Vocabulary
An animal without a backbone is an ____________.
A ____________ is an animal with four feet.
An ____________ is an outer skeleton.
Vocabulary
Match each word with its definition.
A) An animal without a backbone is an __________.
B) A __________ is an animal with four feet.
C) An __________ is an outer skeleton.
A-invertebrate, B-tetrapod, C-exoskeleton
tetrapod
invertebrate
exoskeleton
Lesson 3 Vocab b Review

17. What are the seven classes of vertebrates? Classify
jawless fish, fish with cartilage skeletons, bony fish, amphibians, reptiles, birds, mammals
Classify
Use graphic organizer 11.
What are the seven classes of vertebrates?
Vertebrates: jawless fish, fish with cartilage skeletons, bony fish, amphibians, reptiles, birds, mammals
Alternate Classify
How are vertebrates classified?
Possible answers: Vertebrates are classified in seven groups: jawless fish, cartilaginous fish, bony fish, amphibians, reptiles, birds, and mammals.
How are invertebrates classified?
Invertebrates are classified as sponges, cnidarians, flatworms and roundworms, mollusks, segmented worms, echinoderms, and arthropods.
What characteristics identify an arthropod?
Arthropods have jointed legs, a tough exoskeleton, and a segmented body.
End of Lesson
Lesson 3 GO Review

18. chordate (kôr΄dāt) An animal with a nerve cord running down its back
chordate (kôr΄dāt) An animal with a nerve cord running down its back. (p. 19)
Lesson 3 Vocab a

19. invertebrate (in·vûr΄tә·brāt) An animal without a backbone. (p. 50)
Lesson 3 Vocab d