Birds and Mammals
Birds
The Physics of Flight
Mammals
Table of Contents
Birds and Mammals - Birds
Characteristics of Birds
The bodies of most birds have adaptations for flight.
Birds and Mammals - Birds
Characteristics of Birds
Air sacs and a four-chambered heart help birds obtain oxygen and move it to their cells.
Birds and Mammals - Birds
Characteristics of Birds
Birds have four-chambered hearts and double-loop circulatory systems that efficiently move oxygen to their cells.
Birds and Mammals - Birds
Characteristics of Birds
Some birds like this hawk have a crop and a gizzard. The crop stores food, and the gizzard crushes food.
Birds and Mammals
Previewing VisualsWhen you preview, you look ahead at the material to be read. Preview Figure 1. Then write two questions you have about the diagram in a graphic organizer like the one below. As you read, answer your questions.
Q. How are birds adapted for flight?
A. They have lightweight bones, wings, and contour feathers.
Q. What is the function of contour feathers?
A. They give shape to the body and help the bird balance and steer during flight.
Adaptations for Flight
- Birds
Birds and Mammals
End of Section:Birds
Birds and Mammals - The Physics of Flight
Staying in the Air
The difference in pressure above and below the wings as a bird moves through the air produces an upward force, called lift, that causes the bird to rise.
Birds and Mammals
Relating Cause and EffectA cause makes something happen. An effect is what happens. As you read, identify the physical properties of a bird’s wing that cause lift. Write them down in a graphic organizer like the one below.
Lift
Air flows around the wing.
The shape of the wing causes a difference in air pressure that produces an upward force.
Contour feathers give the wings a smooth shape.
- The Physics of Flight
Cause
Effect
Birds and Mammals
More on Bird Adaptations
Click the PHSchool.com button for an activityabout bird adaptations.
- The Physics of Flight
Birds and Mammals
End of Section:The Physics of
Flight
Birds and Mammals
Mammal Diversity
This circle graph shows the percentages of species of some groups of mammals.
- Mammals
Birds and Mammals
Mammal Diversity
21.8 %
Reading Graphs:
What percentage of species are bats?
- Mammals
Birds and Mammals
Mammal Diversity
78.2 %
Calculating:
What percentage of species are not bats?
- Mammals
Birds and Mammals
Mammal Diversity
The group with the greatest number of species, rodents, would be the tallest.
Graphing:
Suppose you used the data shown in the circle graph to make a bar graph. Which bar would be tallest?
- Mammals
Birds and Mammals
Mammal Diversity
100; no, you do not have to add them because it is a circle chart—the entire chart stands for 100 percent of the items counted— in this case, mammal species.
Predicting:
What total should all the percentages in the pie chart add up to? Do you have to add the percentages to obtain your answer? Explain.
- Mammals
Birds and Mammals
Building VocabularyA definition states the meaning of a word or phrase by telling about its most important feature or function. After you read the section, reread the paragraphs that contain definitions of Key Terms. Use all the information you have learned to write a definition of each Key Term in your own words.
Key Terms: Examples:
- Mammals
mammal The yak is a member of the group of vertebrates called mammals.
mammary gland Every young mammal is fed with milk produced by organs in its mother’s body. These organs are called mammary glands.
diaphragm Mammals breathe in and out because of the combined action of rib muscles and a large muscle called the diaphragm.
Key Terms: Examples:monotreme
marsupial
gestation period
Egg-laying mammals are called monotremes.
Marsupials are mammals whose young are born at an early stage of development and usually continue to develop in a pouch on their mother’s body.
Marsupials have a very short gestation period, the length of time between fertilization and birth.
Key Terms: Examples:placental mammal
placenta
Unlike a monotreme or a marsupial, a placental mammal develops insides its mother’s body until its body systems can function independently.
The name of this group comes from the placenta, an organ in pregnant female mammals that passes materials between the mother and the developing embryo.
Birds and Mammals
Links on Mammals
Click the SciLinks button for links on mammals.
- Mammals
Birds and Mammals
Data Sharing Lab
Click the PHSchool.com button for an activityabout sharing data for the Consumer Lab Keeping Warm.
- Mammals
Birds and Mammals
End of Section:Mammals
Birds and Mammals
Graphic Organizer
Milk from pores or slits on mother’s skin
Hatch from egg
Characteristic Monotremes Marsupials Placental Mammals
How Young Begin Life
How Young Are Fed
Example
Born live, crawl into mother’s pouch
Born live
Milk produced by mother in her pouch
Milk produced by mother
Spiny anteater or duck-billed platypus
Koala, kangaroo, or opossum
Human, giraffe, bear, rabbit, whale, etc.
Birds and Mammals
End of Section:Graphic Organizer