CHAPTER TEN ANIMALS WITH BACKBONES By: Raynald Laurent * Information based on exerts from “Concepts and Challenges in Life Science Third Edition”

WHAT ARE CHORDATES? Gill slits Notochord Lancelet Chordates are animals with backbone, animals closely related to invertebrates and contain a notochord at some point of their development. All chordates have a hollow nerve cord and paired gill slits. This diagram of a Lancelet shows the basic parts. Lancelets are fishlike creatures that makes the sand of the ocean floor their habitat. A lancelets'’ notochord never evolves into a backbone.

WHAT ARE FISHES? Fins Scales Gill cover Eye Mouth Tail fin Fishes are the oldest group of vertebrates appearing more than 500 million years ago. Fishes are coldblooded animals. They use their feathery organs called gills to breathe. Their fins and tail fin are there for them to swim.

WHAT ARE AMPHIBIANS? Amphibians are animals that a have a habitat on land and water at separate parts of their lives. It’s during their young age they live in water and as they grow and develop, and become a mature adult they live on land. Amphibians are also coldblooded with the exception of toads. Amphibians have webbed feet and they use their skin to exchange oxygen and carbon dioxide.

How Do Frogs Develop? Frogs endure drastic changes in there physical appearance and development called metamorphosis. Amphibians go through these changes as well. These are the stages: 1.Frogs lay their eggs in water. 2.The eggs hatch in approximately 12 days and tadpoles are hatched. Tadpoles resemble very small fish. 3.The tadpole grows and develops over time into a young frog. The gills are gone and lungs replace them. At that point the young frog is ready for life on land.

What are reptiles? Reptiles are coldblooded animals with the majority of them having two pairs of legs with clawed feet. They were the first true land animals. Retiles breathe through their lungs. They have a three- chambered or four-chambered heart. There are 6500 different kinds of reptiles

What are birds? Birds, unlike amphibians, are warm- blooded. The characteristics of birds are two wings, two legs, lightweight bones, birds have a beak without teeth and birds lay hard-shelled eggs. The organ system of birds are very developed. Birds have a four-chambered heart. The two upper chambers are the atria and the two lower chambers are the ventricles. There are different kinds of birds, Birds of prey, Wading Birds, Perching Birds, Nonperching and Swimming Birds.

What are mammals? Life Science Third Edition Mammals are warm blooded animals. They are a group of vertebrates that include humans here are some of the characteristics of mammals: Body Hair Body Hair Four-chambered heart Four-chambered heart Highly developed brain and nervous system Highly developed brain and nervous system Female mammals nurse their young Female mammals nurse their young

How do animal embryos develop? The female sex cell called the egg, are laid in water by fish and other animals that make that their habitat. The male sex cell called sperm is united with the egg in the process of fertilization. Eggs are fertilized outside of the female body. The developing organism called the embryo develops inside the egg and consumes food stored in the egg. Eggs of mammals are fertilized inside the body of the mother. The embryo develops inside the mother’s body. The embryo gets its food from the mother, the digested food and oxygen from the mothers bloodstream, is passed into the bloodstream of the embryo. Water Animals Land Animals