GRADE LEVELS: 5-8

TIME ALLOTMENT: One or two 45-minute class periods

OVERVIEW:

In this lesson, students will learn about the various attributes of different predators on the African grasslands which make them effective hunters, and about the attributes their prey have developed to help them survive the predators’ attacks. The development of both sets of attributes will be presented as part of natural selection—a process which takes varied forms (and produces varied results) in the earth’s different ecosystems.

In the Introductory Activity, students will use an online interactive to familiarize themselves with the physical attributes of the cheetah which make it such an effective predator. In the Learning Activities, students explore the cheetah’s use of these attributes in pursuit of its equally well-adapted prey—the gazelle—through video from the “Hunters and Herds” episode of the PBS series NATURE, which also discusses the similar contest between lions and wildebeests. The Culminating Activity challenges students to research, compare, and contrast predator/prey relationships in earth’s different ecosystems, and present their findings to the class.

This lesson is intended for use during study on natural selection and adaptations, or a unit on the food chain/web.

SUBJECT MATTER: Science, Biology

LEARNING OBJECTIVES:

Students will be able to:

• Identify the attributes of different predators which contribute to their effectiveness as predators
• Identify the attributes of different prey animals which contribute to their ability to elude predators
• Discuss how the attributes of both predator and prey animals have developed in a process of natural selection
• Compare and contrast predator/prey relationships from different ecosystems around the world.

STANDARDS:

National Science Education Standards

Life Science

Content Standard C

As a result of their activities in grades 5-8, all students should develop understanding of:

1. Structure and function in living systems
2. Reproduction and heredity
3. Regulation and behavior
4. Populations and ecosystems
5. Diversity and adaptations of organisms

MEDIA COMPONENTS:

Video: NATURE: “Moments of Impact– Hunters & Herds”

Clip #1 “Cheetah vs. Gazelle”

An animation-enhanced comparison of the strengths and weaknesses of this predator and prey pair.

Clip #2 “Lion vs. Wildebeest”

An animation-enhanced comparison of the strengths and weaknesses of this predator and prey pair.

Websites:

“Toki’s Survival Challenge”

An interactive in which a cheetah hunts its prey on the African savannah. From the PBS NATURE web site.

“Anatomy of a Cheetah”

A simple interactive highlighting the primary physical attributes of the cheetah as a predator.

MATERIALS:

For the class:

• 1 computer w/ internet connection and projector

For each group of 3-5 students:

• 1 computer w/ internet connection

PREP FOR TEACHERS:

Prior to teaching this lesson, you will need to:

Preview all of the video segments and websites used in the lesson.

Download the video segments used in the lesson to your classroom computer, or prepare to watch them using your classroom’s internet connection.

Bookmark the website used in the lesson on each computer in your classroom. Using a social bookmarking tool such as del.icio.us or diigo (or an online bookmarking utility such as portaportal) will allow you to organize all the links in a central location.

Next: Proceed to Activities.

Excerpts from the NATURE episode, “Moments of Impact: Hunters and Herds”

Cheetah vs. Gazelle
(View full post to see video)

Lion vs. Wildebeest
(View full post to see video)

Downloadable QuickTime versions of the video segments:
(Note: To download a video, right click on the video title and click “Save Link As…’ or “Save Target As…”. On a Mac, press the CTRL key and simultaneously click the mouse, then save the link.)

Video Clips

1.“Cheetah vs. Gazelle”

2.“Lion vs. Wildebeest”

GRADE LEVEL: 5-8

TOPIC/SUBJECT MATTER: Life Science

TIME ALLOTMENT: One to two 45-minute class periods

OVERVIEW:

During this video-enhanced lesson, students will watch video segments from the NATURE film “The Secret World of Sharks and Rays” and learn about adaptations that have helped sharks and rays survive. Students will explore similarities and differences between sharks, rays and other fish. They will watch segments that provide information about physical features and behaviors that have helped sharks and rays survive, with specific attention paid to the angel, wobbegong and saw sharks and the electric, sting and manta rays. Students will work in small groups to research a specific type of shark or ray and share their findings with the class. Students will discover that different types of sharks and rays have different temperaments and diets and that some of the largest sharks and rays are the most gentle.

MEDIA RESOURCES

Video

Clip 1

Fish, Sharks and Rays: A comparison of fish, sharks and rays.

Clip 2

A Close Look at Sharks: A close look at angel, wobbegong and saw sharks and their survival techniques.

Clip 3

A Close Look at Rays: A close look at electric, sting and manta rays and their survival techniques.

Access the streaming and downloadable video segments for this lesson at the Video Segments Page.

Web sites

Ichthyology at the Florida Museum of Natural History

This site features a rich variety of information, games and photographs of a variety of fish, including sharks and rays. The following sections are recommended for this lesson:

• Sharks- This section features information, games and photographs of sharks.
• Biological Profiles- This section provides photographs and detailed information about specific sharks and rays, as well as other fish.

Kidzone Fun Facts for Kids: Sharks

This Web site features a variety of photographs, activities and facts about sharks.

National Geographic: Sharks
This Web site features many photos and facts about sharks, which can be used in this lesson.

Seaworld: Sharks and Rays

This site contains a variety of facts, photographs and diagrams of sharks and rays.

STANDARDS:

National Science Education Standards, Grades 5-8

LIFE SCIENCE: Content Standard C

As a result of their activities in grades 5-8, all students should develop understanding of

• Regulation and behavior
  • Behavior is one kind of response an organism can make to an internal or environmental stimulus. A behavioral response requires coordination and communication at many levels, including cells, organ systems, and whole organisms. Behavioral response is a set of actions determined in part by heredity and in part from experience.
  • An organism’s behavior evolves through adaptation to its environment. How a species moves, obtains food, reproduces, and responds to danger are based in the species’ evolutionary history.
• Populations and ecosystems

• Populations of organisms can be categorized by the function they serve in an ecosystem. Plants and some microorganisms are producers-they make their own food. All animals, including humans, are consumers, which obtain food by eating other organisms. Decomposers, primarily bacteria and fungi, are consumers that use waste materials and dead organisms for food. Food webs identify the relationships among producers, consumers, and decomposers in an ecosystem.

• Diversity and adaptations of organisms
  • Millions of species of animals, plants, and microorganisms are alive today. Although different species might look dissimilar, the unity among organisms becomes apparent from an analysis of internal structures, the similarity of their chemical processes, and the evidence of common ancestry.

• Biological evolution accounts for the diversity of species developed through gradual processes over many generations. Species acquire many of their unique characteristics through biological adaptation, which involves the selection of naturally occurring variations in populations. Biological adaptations include changes in structures, behaviors, or physiology that enhance survival and reproductive success in a particular environment.

MATERIALS

For each group of 2-3 students:

• Books, reference materials and/or computers to conduct research on sharks and rays.

For the class:

• A large sheet of paper or board and something with which to write.
• A photograph of a bull shark and a photograph of a whale shark. (See “Prep for Teachers” section for details.)
• One computer for the teacher with a digital projection system (to play video clips either downloaded or streaming from the Web).

OBJECTIVES

Students will be able to:

• Discuss similarities and differences between sharks, rays and other fish;
• Describe physical features and characteristics that have helped sharks survive, with specifics about angel, wobbegong and saw sharks;
• Provide details of physical features and characteristics that have helped rays survive, with specifics about electric, sting and manta rays;
• Explain that there are many different types of sharks and rays, with varied skills, physical features, temperaments and diets;
• Explain that some sharks and rays are harmful to humans, while others are not and provide specific examples of harmful and gentle species;
• Discuss that sometimes the largest species can be the most gentle;
• Provide detailed information about one species of shark or ray.

PREP FOR TEACHERS

Prior to teaching this lesson, you will need to:

Preview all of the video segments and Web sites used in the lesson.

Download the video clips used in the lesson to your classroom computer, or prepare to watch them using your classroom’s Internet connection.

Bookmark the Web sites used in the lesson on each computer in your classroom. Using a social bookmarking tool such as del.icio.us or diigo (or an online bookmarking utility such as portaportal) will allow you to organize all the links in a central location.

Print out one photo of a whale shark and one photo of a bull shark to show the class. Make sure that the image of the whale shark is about 3 times larger than the bull shark. See the “Web sites” section above for a list of sites with shark photos.

Proceed to ACTIVITIES

Downloadable QuickTime versions of the video segments:
(Note: To download a video, right click on the video title and click “Save Link As…’ or “Save Target As…”. On a Mac, press the CTRL key and simultaneously click the mouse, then save the link.)

Clip 1

Fish, Sharks and Rays

Clip 2

A Close Look at Sharks

Clip 3

A Close Look at Rays