 Fishes  Amphibians  Reptiles  Mammals  Monotremes Marsupials Placental Mammals

The ancestral animals at the beginning of the evolutionary tree are:  1. eukaryotic  2. multicellular  3. Animals are heterotrophic

1. Invertebrates:  Have Exoskeletons which are: hard or tough outer coverings that provide a framework of support for soft body tissues 2. Vertebrates  Have Endoskeletons: internal bones (a backbone) or cartilage that provide support

 Symmetry: Similarity or balance among body structures of organisms  3 TYPES OF SYMMETRY:  1. Radial symmetry: if you were to slice the organism in any plane along it’s central axis, each side would roughly equal  Example: jellyfish  2. Bilateral symmetry : if you were to slice the organism along its central axis each side would be mirror images of each other  Example:  hummingbird

 3. Asymmetry symmetry: No symmetry  Example: sponge

 Fertilization occurs when the sperm penetrates the egg to form a fertilized egg cell called the zygote.  Internal fertilization: fertilization happens inside the female organism  External fertilization: fertilization happened outside of the female organism

 brain, the spinal cord, and nerves.  the nervous system is your body's control system. It sends, receives, and processes nerve impulses throughout the body.  These nerve impulses tell your muscles and organs what to do and how to respond to the environment.  There are three parts of your nervous system that work together:  1. Central nervous system –main control system  2. Peripheral nervous system- controls muscles  3. Autonomic nervous system- control breathing and heart beat

1. Open circulatory system: blood is pumped out of vessels into open spaces surrounding the body organs (Contains NO blood vessels). -Oxygen and nutrients diffuse into tissues that are bathed in blood and carbon dioxide diffuses from tissues into the blood.  EX.  Mollusk

2. Closed circulatory system: -blood is confined to blood vessels as it moves through the body. -A closed system efficiently transports oxygen and nutrients to cells where they are converted to usable forms of energy.

Arthropod Features:  1. are segmented invertebrates  2. have bilateral symmetry  3 have exoskeletons with jointed appendages.

 1. Crustaceans 2. Spiders and their relatives (scorpions,ticks & mites )

 3. Insects and their relatives (Centipedes and Millipedes) 

The vertebral column, or spinal column, is the hallmark feature of vertebrates Examples:  Fishes  Amphibians  Reptiles  Birds  Mammals

 Skeletal system: Have back bone  Circulatory System: respiration through gills  Reproductive system: External fertilization of shell-less eggs

 Spend part of their life in the water.  They are the first step water animals took to become land animals  Fertilization is external and the shell-less eggs must be laid and fertilized in water.  Tadpoles hatch from the egg and undergo metamorphosis from a fishlike animal to an air-breathing one.

Characteristics that allow reptiles to succeed on land:  1. Shelled egg – provides fluid environment for developing embryo  2. Scaly skin: protects against moisture loss  3. More efficient circulatory system & respiratory systems.

Along the Atlantic coastline of Southern Florida

 Amniotic egg is covered with a protective shell and has several internal membranes  The leathery shell protects the internal fluids and embryo

 Reptiles regulate their body temperatures by basking in the sun for warmth or burrowing in the ground to cool off

 Reptiles have internal fertilization.  After fertilization, the egg develops to form the new embryo and an amniotic egg.

 Two characteristics that distinguish members of class Mammalia:  1. Hair  2. Mammary glands

 1. Monotremes  2. Marsupials  3. Placental mammals

 Are the only mammals that lay eggs  Duck-billed platypus & Echidna

 Very short period of development in the uterus  Crawl into a pouch made of skin and hair and continue development while being nourished by milk from the mother’s mammary glands

 Give birth to young that do not need further development.