1 / 8

Chordate Cladogram

Chordate Cladogram. Section 30-1. Mammals. Birds. Reptiles. Amphibians. Fishes. Nonvertebrate chordates. Invertebrate ancestor. Interest Grabber. Section 30-3. Declining Numbers of Frogs

patino
Download Presentation

Chordate Cladogram

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chordate Cladogram Section 30-1 Mammals Birds Reptiles Amphibians Fishes Nonvertebratechordates Invertebrate ancestor

  2. Interest Grabber Section 30-3 • Declining Numbers of Frogs • Ecologists have recently noticed declining numbers of certain types of amphibians in a variety of places. Some scientists have hypothesized that this decline might be a result of toxins in the environment. • Work with a partner to discuss and answer the questions that follow. 1. What characteristics of amphibians might make them more susceptible to environmental toxins than other types of animals? 2. Frogs reproduce in water. Why might toxins in aquatic ecosystems affect the reproductive success of frogs? 3. Can you think of any other possible explanations for the reduced numbers of amphibians observed?

  3. Section 3 Answers Interest Grabber Answers 1. What characteristics of amphibians might make them more susceptible to environmental toxins than other types of animals? Amphibians live both in water and on land, have moist skins that allow the exchange of substances, and do not have protective scales or a thick impermeable skin. 2. Frogs reproduce in water. Why might toxins in aquatic ecosystems affect the reproductive success of frogs? Eggs and tadpoles may be more sensitive to toxins in the water during these developmental stages. 3. Can you think of any other possible explanations for the reduced numbers of amphibians observed? Possible answers: more predators; presence of a viral, bacterial, or fungal infection; decreasing food supply; and normal fluctuations in population size.

  4. Section Outline Section 30-3 • Amphibians A. What Is an Amphibian? B. Evolution of Amphibians C. Form and Function of Amphibians 1. Feeding 2. Respiration 3. Circulation 4. Excretion 5. Reproduction 6. Movement 7. Response D. Groups of Amphibians 1. Salamanders 2. Frogs and Toads 3. Caecilians E. Ecology of Amphibians

  5. Concept Map Water Land Bones Lungs Ribs Efficientmovement Breathingair Support andprotection Section 30-3 Amphibians means “Double life” as larvæ they live in adults they live on and have special adaptations such as are that allow for that allow that provide are

  6. The Life Cycle of a Frog Section 30-3 Adult Frog Adults are typically ready tobreed in about one to two years. Young Frog Frog eggs are laid in water and undergo external fertilization. The eggs hatch into tadpoles a few days to several weeks later. Fertilized Eggs Tadpoles Tadpoles gradually grow limbs, lose their tails and gills, and become meat-eaters as they develop into terrestrial adults.

  7. Video Video

  8. End of Custom Shows • This slide is intentionally blank.

More Related