Bellwork 1: 1-8-2014Briefly write about a real scientific observation you made over the break. I will only call on 3 of you to share

VertebratesChapter 3

VertebratesThere 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 HaveAll vertebrates have:

Backbones, brains, craniums (skulls), closed circulatory systems with veins, arteries, and capillaries, continuously beating heart to keep blood flowing

Vertebrates 2 GroupsVertebrates can be divided into two groups:

Ectotherms & EndothermsEctotherms are animals that use the environment to regulate their body temperatures.They generally bask in the sun or bury themselves for heat or coolingReptiles, fish, and amphibians are all ectotherms

Ectotherms

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

Endotherms

VertebratesVertebrates’ tissues are made mostly of salty waterThis tissue freezes/dies at 31.1’ FMost vertebrates live in areas with temperature ranges from 32’-122’FSome have adapted to harsher environments

AdaptationsPolar 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

Review1. 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

Review3. 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, amphibiansEndotherms: birds, mammals

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

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

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

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

Review1.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.

Review3. Which organisms have an easier time regulating their body temperatures, ectotherms that live on land or water? Why?

Those that live in waterBecause water temperature is not as volatile as air temperature.

Review4. What are some ways that ectotherms regulate their body temperatures?

Basking, burying, changing color

ReptilesOver 7000 species of reptilesThe study of reptiles and amphibians is herpetologyHerpo in Greek is “to creep or crawl”All reptiles have lungs and scaly skin

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

ReptilesScales protect the skin underneath from drying outRetiles have bone skeletons and most have teethTheir teeth range from blunt crushing teeth to thin needle-like fangs

Reptiles

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

ReptilesReptiles 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.

ReptilesAll reptiles reproduce through internal fertilizationSome lay leathery eggs and the young are hatched Others store their eggs inside their bodies and the young are born live

Live birth

ReptilesYoung reptiles look like miniature adultsMost reptile mothers do not take care of their young

Common Reptile Groups1. Turtles2. Lizards3. Snakes4. Alligators and Crocodiles

TurtlesTurtles’ bodies are protected by a shell formed of plates of boneSome shells can support a weight 200 X their own!

Turtles

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