Bellwork 1: Briefly write about a real scientific observation you made over the break. I will only call on 3 of you to share

Vertebrates Chapter 3

Vertebrates There are more than 50,000 species of vertebrates in this world. A vertebrate is an animal with a backbone that supports and protects the spinal cord.

Vertebrates All Have All vertebrates have: Backbones, brains, craniums (skulls), closed circulatory systems with veins, arteries, and capillaries, continuously beating heart to keep blood flowing

Vertebrates 2 Groups Vertebrates can be divided into two groups: Ectotherms & Endotherms Ectotherms are animals that use the environment to regulate their body temperatures. They generally bask in the sun or bury themselves for heat or cooling Reptiles, fish, and amphibians are all ectotherms

Ectotherms

Endotherm Endotherms are organisms that internally regulate their body temperatures. Their internal temperature remains generally the same whether they are in hot or cold environments Birds and mammals are examples of endotherms.

Endotherms

Vertebrates Vertebrates’ tissues are made mostly of salty water This tissue freezes/dies at 31.1’ F Most vertebrates live in areas with temperature ranges from 32’-122’F Some have adapted to harsher environments

Adaptations Polar bears have thick layers of fat to insulate them from the cold Some fish have chemicals in their blood that act like antifreeze to allow them to live in cold arctic water

Review 1. What do vertebrates have in common? Backbones, brains, craniums (skulls), closed circulatory systems with veins, arteries, and capillaries, continuously beating heart to keep blood flowing 2. What are the two general groups of vertebrates? Ectotherms, endotherms

Review 3. What distinguishes these two groups? Their ability, or lack there of, to regulate their internal temperature 4. In general, what animals are part of each group? Ectotherms: reptiles, fish, amphibians Endotherms: birds, mammals

Ectotherms Ectotherms’ body temperature and body functions are regulated by the outside temperature Not cold-blooded: ectotherms are not called cold-blooded anymore because some actually have a higher internal temperature than endotherms

Air vs. Water temp Because air temperatures change more than water temperatures, land ectotherms vary more than water ectotherms Due to this variance, land ectotherms seek sun or shade to help regulate these changes

Ectotherms Regulation Many ectotherms hide from predators at night because they are sluggish from lack of heat energy Others prey at night (mostly in hot climates) and stay out of extreme temperatures during the day

Ectotherm Regulation Ectotherms can also change color to help regulate their body temperatures. Darker colors absorb heat while lighter colors reflect heat.

Review 1.What is the distinguishing feature of ectohterms? They regulate their internal temperature using the sun’s energy 2. Why is cold-blooded a confusing term to describe ectotherms? Many ectotherms have warmer internal temperatures that endotherms.

Review 3. Which organisms have an easier time regulating their body temperatures, ectotherms that live on land or water? Why? Those that live in water Because water temperature is not as volatile as air temperature.

Review 4. What are some ways that ectotherms regulate their body temperatures? Basking, burying, changing color

Reptiles Over 7000 species of reptiles The study of reptiles and amphibians is herpetology Herpo in Greek is “to creep or crawl” All reptiles have lungs and scaly skin

Reptiles Most reptiles shed their entire skin at once rather than one cell at a time like us!

Reptiles Scales protect the skin underneath from drying out Retiles have bone skeletons and most have teeth Their teeth range from blunt crushing teeth to thin needle-like fangs

Reptiles Many reptiles have a muscular, flexible, sticky tongue for catching insects.

Reptiles Reptiles generally have well developed organs. (snakes are deaf and some lizards don’t have eyes) Crocodiles and alligators have very advanced organ systems that have allowed them to thrive for millions of years.

Reptiles All reptiles reproduce through internal fertilization Some lay leathery eggs and the young are hatched Others store their eggs inside their bodies and the young are born live

Live birth

Reptiles Young reptiles look like miniature adults Most reptile mothers do not take care of their young

Common Reptile Groups 1. Turtles 2. Lizards 3. Snakes 4. Alligators and Crocodiles

Turtles Turtles’ bodies are protected by a shell formed of plates of bone Some shells can support a weight 200 X their own!

Turtles

Turtles are toothless, but have a beaklike structure to eat plants and animals