End Show Slide 1 of 50 Copyright Pearson Prentice Hall Biology

End Show Slide 2 of 50 Copyright Pearson Prentice Hall 31-1 Reptiles

End Show 31-1 Reptiles Slide 3 of 50 Copyright Pearson Prentice Hall What Is a Reptile? What are the characteristics of reptiles?

End Show 31-1 Reptiles Slide 4 of 50 Copyright Pearson Prentice Hall What Is a Reptile? A reptile is a vertebrate that has dry, scaly skin, lungs, and terrestrial eggs with several membranes. These characteristics enable reptiles to live their entire lives out of water.

End Show 31-1 Reptiles Slide 5 of 50 Copyright Pearson Prentice Hall What Is a Reptile? Reptilian skin is dry and covered with thick, protective scales. This prevents the loss of body water in dry environments. The scaly layer of skin doesn’t grow, so it must be shed periodically as the reptile increases in size.

End Show 31-1 Reptiles Slide 6 of 50 Copyright Pearson Prentice Hall Evolution of Reptiles Reptiles were the first vertebrates that were not dependent on water for reproduction. The first reptile fossil dates back to the Carboniferous Period.

End Show 31-1 Reptiles Slide 7 of 50 Copyright Pearson Prentice Hall Evolution of Reptiles Dinosaurs During the late Triassic and Jurassic periods, a great adaptive radiation of reptiles took place. The Mesozoic Era is often called the Age of Reptiles.

End Show 31-1 Reptiles Slide 8 of 50 Copyright Pearson Prentice Hall Evolution of Reptiles Triassic Reptiles

End Show 31-1 Reptiles Slide 9 of 50 Copyright Pearson Prentice Hall Evolution of Reptiles Dinosaur structure and behavior varied: Ranged in size from small to enormous. Ran on two legs or on four legs. Ate leafy plants or other animals. Some lived in small family groups. Some may have had feathers.

End Show 31-1 Reptiles Slide 10 of 50 Copyright Pearson Prentice Hall Evolution of Reptiles All of dinosaurs belonged to one of two major groups: Ornithischia, or “bird-hipped” dinosaurs Saurischia, or “lizard-hipped” dinosaurs

End Show 31-1 Reptiles Slide 11 of 50 Copyright Pearson Prentice Hall Evolution of Reptiles At the end of the Cretaceous, a mass extinction occurred that killed the dinosaurs as well as other plant and animal groups.

End Show 31-1 Reptiles Slide 12 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles How are reptiles adapted to life on land?

End Show 31-1 Reptiles Slide 13 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Tough, scaly skin and the ability to control body temperature are two adaptations to terrestrial life.

End Show 31-1 Reptiles Slide 14 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Adaptations that have contributed to the success of reptiles on land are: well-developed lungs a double-loop circulatory system a water-conserving excretory system strong limbs internal fertilization shelled, terrestrial eggs

End Show 31-1 Reptiles Slide 15 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Body Temperature Control Reptiles are ectotherms. Ectotherms are animals that rely on behavior to control body temperature. To warm up, they bask in the sun or stay under water at night. To cool down, they move to the shade or take shelter in underground burrows.

End Show 31-1 Reptiles Slide 16 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Feeding Reptiles eat a wide range of foods. Iguanas eat plants. Snakes eat small animals, bird eggs, or other snakes. Crocodiles and alligators eat fish and land animals. Chameleons eat insects.

End Show 31-1 Reptiles Slide 17 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Respiration Reptile lungs are spongy, allowing for a larger area of gas-exchange. Many reptiles have muscles around the ribs that expand and collapse the chest cavity. Most reptiles have two lungs, but certain species of snakes have just one lung.

End Show 31-1 Reptiles Slide 18 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Circulation Reptiles have a double-loop circulatory system: One loop brings blood to and from the lungs. One loop brings blood to and from the rest of the body.

End Show 31-1 Reptiles Slide 19 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Kidney Liver Heart Cloaca Bladder Lung Digestive tract

End Show 31-1 Reptiles Slide 20 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Reptile hearts have two atria and either one or two ventricles. Most reptiles have one ventricle with a partial septum that separates oxygen-rich and oxygen- poor blood. Crocodiles and alligators have two atria and two ventricles.

End Show 31-1 Reptiles Slide 21 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Right atrium Left atrium Incomplete division Ventricle From body To lungs To body From lungs

End Show 31-1 Reptiles Slide 22 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Excretion Urine is produced in the kidneys. In some reptiles, urine flows in tubes directly into a cloaca. In others, a bladder stores urine before it is expelled.

End Show 31-1 Reptiles Slide 23 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Other reptiles convert ammonia into uric acid. In the cloaca, urine is reduced to crystals of uric acid that form a pasty white solid. By eliminating solid wastes, a reptile can conserve water.

End Show 31-1 Reptiles Slide 24 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Response Reptilian brains are similar to amphibians. Their cerebrum and cerebellum are more developed than other parts of the brain.

End Show 31-1 Reptiles Slide 25 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Reptiles that are active in the day have complex eyes and see color well. Many snakes also have an extremely good sense of smell. Most reptiles have sensory organs in the mouth that detect chemicals when reptiles flick their tongues.

End Show 31-1 Reptiles Slide 26 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Reptiles have simple ears with an external eardrum and a single bone that conducts sound to the inner ear. Snakes can also pick up vibrations in the ground through bones in their skulls. Some snakes can detect the body heat of their prey.

End Show 31-1 Reptiles Slide 27 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Movement Reptiles with legs have large strong limbs. Some have legs that are rotated further under the body, enabling them to carry more body weight.

End Show 31-1 Reptiles Slide 28 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles The legs and feet of many aquatic turtles have developed into flippers. Reptiles’ backbones help accomplish much of their movement.

End Show 31-1 Reptiles Slide 29 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles Reproduction Most reptiles are oviparous, laying eggs that develop outside the mother’s body. All reptiles reproduce by internal fertilization, in which the male deposits sperm inside the female’s cloaca. After fertilization, the female’s reproductive system covers the embryo with several membranes and a leathery shell.

End Show 31-1 Reptiles Slide 30 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles The shell and membranes protect the embryo and prevent the egg from drying out. This type of egg, an amniotic egg, is one of the most important adaptations to life on land. An amniotic egg has four membranes—the amnion, the yolk sac, the chorion, and the allantois.

End Show 31-1 Reptiles Slide 31 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles The amnion is a fluid-filled sac that surrounds and cushions the developing embryo. Amnion

End Show 31-1 Reptiles Slide 32 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles The chorion regulates the transport of oxygen and carbon dioxide between the surface of the egg and the embryo. Chorion

End Show 31-1 Reptiles Slide 33 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles The yolk sac contains the yolk that serves as a nutrient-rich food supply for the embryo. Yolk sac

End Show 31-1 Reptiles Slide 34 of 50 Copyright Pearson Prentice Hall Form and Function in Reptiles The allantois stores the waste produced by the embryo. Allantois

End Show 31-1 Reptiles Slide 35 of 50 Copyright Pearson Prentice Hall Groups of Reptiles What are the four living orders of reptiles?

End Show 31-1 Reptiles Slide 36 of 50 Copyright Pearson Prentice Hall Groups of Reptiles The four surviving groups of reptiles are: lizards and snakes crocodilians turtles and tortoises tuatara

End Show 31-1 Reptiles Slide 37 of 50 Copyright Pearson Prentice Hall Groups of Reptiles Lizards Most lizards have four legs and clawed toes. Most lizards have external ears and movable eyelids. Some lizards have evolved into highly specialized forms.

End Show 31-1 Reptiles Slide 38 of 50 Copyright Pearson Prentice Hall Groups of Reptiles Snakes Snakes have no legs. Snakes have immovable eyelids and no external ear openings. Snakes are efficient predators.

End Show 31-1 Reptiles Slide 39 of 50 Copyright Pearson Prentice Hall Groups of Reptiles Crocodilians Crocodilians have long, broad snouts and a squat appearance. They prey on animals such as fishes, deer, and even humans. Females guard their eggs from predators and watch over their young after the eggs hatch.

End Show 31-1 Reptiles Slide 40 of 50 Copyright Pearson Prentice Hall Evolution of Reptiles Crocodilians live only where it is warm year-round. Alligators and caimans live only in fresh water and are found almost exclusively in North and South America. Crocodiles live in either fresh or salt water and are native to Africa, India, and Southeast Asia.

End Show 31-1 Reptiles Slide 41 of 50 Copyright Pearson Prentice Hall Groups of Reptiles Turtles and Tortoises Turtles live in water. Tortoises live on land. A terrapin is a turtle that lives in water that is somewhat salty.

End Show 31-1 Reptiles Slide 42 of 50 Copyright Pearson Prentice Hall Groups of Reptiles Turtles and tortoises have a two-part shell built into the skeleton: a dorsal part, or carapace a ventral part, or plastron The head, legs, and tail emerge from holes where the carapace and plastron join. Tortoises and most turtles pull into their shells for protection.

End Show 31-1 Reptiles Slide 43 of 50 Copyright Pearson Prentice Hall Groups of Reptiles Tuataras Tuataras are found only on a few islands off New Zealand. They lack external ears and retain primitive scales. They have a “third eye,” which is part of a complex organ located on top of the brain.

End Show 31-1 Reptiles Slide 44 of 50 Copyright Pearson Prentice Hall Ecology of Reptiles Many reptiles are in danger because of habitat destruction. Humans hunt reptiles for food, for pets, and for their skins. Laws protect some species, but more conservation efforts are needed to counteract their dwindling numbers.

End Show - or - Continue to: Click to Launch: Slide 45 of 50 Copyright Pearson Prentice Hall 31-1

End Show Slide 46 of 50 Copyright Pearson Prentice Hall 31-1 Most reptiles reproduce with a.external fertilization and external development. b.internal fertilization and internal development. c.internal fertilization and external development in water. d.internal fertilization and external development in shelled eggs.

End Show Slide 47 of 50 Copyright Pearson Prentice Hall 31-1 The yolk sac of a reptile egg functions as a a.membrane that exchanges oxygen and carbon dioxide for the embryo. b.membrane that stores wastes produced by the embryo. c.source of nutrient-rich food for the developing embryo. d.shock-absorbing fluid-filled sac protecting the embryo.

End Show Slide 48 of 50 Copyright Pearson Prentice Hall 31-1 Reptiles are a.ectotherms. b.endotherms.

End Show Slide 49 of 50 Copyright Pearson Prentice Hall 31-1 Reptiles with the most well-developed hearts include a.turtles and alligators. b.crocodiles and turtles. c.crocodiles and alligators. d.alligators and lizards.

End Show Slide 50 of 50 Copyright Pearson Prentice Hall 31-1 The two parts of a turtle or tortoise's shell are the a.terrapin and plastron. b.carapace and plastron. c.carapace and terrapin. d.terrapin and carapace.

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