Unit A: How Living Things Function
1. Get Set to Explore
- backbone: The series of bones that runs down the back of animals called vertebrates.
- lungs: Organs inside the body of certain animals, including mammals, that aid with breathing and getting oxygen into the blood.
- mammal: An animal that has hair or fur and produces milk to feed its young.
- warm-blooded: Having a body temperature that does not change when the temperature of the surroundings changes; mammals are warm-blooded.
- Show students still or moving pictures of dolphins and have students identify these animals. Let students describe what they observe about these animals, including where they live, what they look like, and how they behave. Record their ideas on the board.
- Go over definitions of the vocabulary words, referring to students' observations of the dolphins. Refer to Student Edition pages A36-A37 for additional context for discussing vocabulary terms.
- Explain that in the simulation, students will be comparing traits people have with traits that dolphins have. Pose the Discover! question. Refer students to the list they made earlier of characteristics of dolphins. Make that the first column of a chart on the board. The second column of the chart will be used for listing traits of humans. Read or ask a volunteer to read the dolphin trait listed at the top of the chart. Encourage volunteers to identify a related trait of humans and write the trait on the board. Continue down the list and then let students add traits to either column.
- Direct students to make a two-column chart to record traits of dolphins and traits of humans, or hand out copies of a chart for students to use during the simulation.
2. Guide the Exploration
- Show students how to launch the Discover! Simulation. Encourage students to begin filling out their chart even during the introduction of the activity.
- As students begin Step 2, point out the list of labels down the center of the screen. These labels include all of the characteristics that these animals share. Note that when they click the feature labels, the characteristics of the dolphin and corresponding features of the human will be highlighted. Students should compare the highlighted features. The simulation compares seven pairs of features.
- After students have finished the exploration, return to the class chart on the board. Let students add traits of humans and dolphins that they compared during the simulation. Also, encourage them to revise or correct any information from the earlier discussion that they think needs to be changed, referring to their own charts.
- Continue referring to the chart and ask a volunteer to read the first two sentences of Step 3's Wrap-up text aloud. After the student reads each element listed in the second sentence, let the class check for similar information in the chart on the board. Students should think back to features highlighted in the simulation that support each trait listed. Note, however, that the trait of producing milk is not listed in the simulation; go over the definition of mammal and explain that milk production is implied by this definition.
- Assign another volunteer to read the third through the sixth sentence of the Wrap-up text. Let students continue making additions to the class chart. Summarize the simulation by reading the last sentence of the Wrap-up text aloud to the class. Then, read the Extension aloud and have students return to the simulation. Encourage them to add to their charts to organize information related to the answer. Through class discussion, encourage students to note the following adaptations:
- flexible backbone to aid in motions necessary for swimming
- blowhole on top of head for air intake; sealed when dolphin goes underwater
- hairlessness and smooth skin for ease of movement in water
- flippers and flukes to aid swimming
- ability of babies to swim at birth
If time permits, present students with the following question:
- Critical Thinking Apply Dolphins and humans both use lungs to breathe air. Neither can breathe underwater. What would happen if a dolphin did not have a seal to cover its blowhole when it went underwater? Answer: The dolphin could get water in its lungs, which would cause it to drown.
4. Reaching All Learners
English Language Learners
Print a copy of each of the diagrams of the humans and the dolphins from the simulation. Let students label any body parts that they already know. Then go over the names or the organs and body parts that students are less familiar with. Discuss the function of each of the labeled parts. Let students refer to their diagrams as they do the simulation.