Animal Kingdom -Vertebrates Mr. Cobb Biology

1 Zoology: study of animals

The Kingdom Animalia No cell wall Heterotrophic Motile Sexual reproduction Tissue / organs Multicellular Distinct body plan The Kingdom Animalia Animals are heterotrophic, which means they rely directly or indirectly on other organisms for their nourishment. Animals are multicellular organisms, and unlike plants, their cells do not have cell walls. All animals are motile at some time in their life, some even from the moment of birth. While a few animal groups are able to reproduce asexually, most reproduce sexually. Most animals are diploid, and the cells of adults contain two copies of the genetic material. Embryological development in animals is characterized by distinct stages. Following fertilization, the first divisions of the cell forms what is called a zygote. After one hundred or so mitotic divisions, the hollow ball of cells develops into a blastula. When the blastula folds in on itself, it forms a double-walled structure, the gastrula, that has an opening to the outside called the blastopore. The inner layer of the gastrula becomes the endoderm, or the digestive tract. The outer layer usually develops into the ectoderm, or the nerve and epidermal cells of the adult. A third layer is the mesoderm, which develops into the other internal organs. Animals have their own body plan, or symmetry, and internal organization. While sponges are asymmetrical, virtually all other animals exhibit radial or bilateral symmetry. The Cnidarians (hydras, jellies, coral polyps, and sea anemones) and Ctenophora (comb jellies) include radially symmetric animals. Bilateral symmetry is associated with cephalization. References Campbell, N. E. & Reece, J. B. (2002) Biology (6th ed.). Benjamin Cummings. Image Reference Weller, K. USDA Agricultural Research Service. Retrieved 12-11-2006 from http://www.ars.usda.gov/is/graphics/photos/

Kingdom Animalia The animal kingdom is in the domain eukarya. This kingdom consists of different phyla, including: Mollusca Nematoda Annelida Arthropoda Chordata

Kingdom Animalia Organisms in the animal kingdom are sometimes divided into two groups: Vertebrates – organisms that have a notochord (develops into a backbone) Invertebrates – organisms that do NOT have a notochord.

Vertebrates All vertebrates belong to the phylum chordata. They have a dorsal nerve cord that develops into a spinal cord. All vertebrates have an internal skeleton known as an endoskeleton.

Vertebrates There are several classes included in the chordata phylum: Fish Amphibia Reptilia Aves Mammalia

Fish There are 3 different classes of fish: Jawless fish (class Agnatha) – these fish have no jaws, they attach themselves to the side of a fish and suck its blood. Cartilaginous fish (class chondrichthyes) have no bones, only cartilage. Bony fish (class Osteichthyes) – these fish have bones and cartilage.

Jawless Fish                            

Cartilaginous Fish

Bony Fish

Fish Fish use gills to breathe. Gills are full of blood vessels and allow for gas exchange through diffusion. Fish’s scales are used to cover and protect their body. Fish have hearts with two chambers. The heart pumps deoxygenated blood to the gills, then throughout the body.

Fish – Gas Exchange

Fish Fish get their body temperature from their environment (ectotherms) Most fish release eggs and sperm into the water, but some (like sharks) undergo internal fertilization and give birth to live offspring.

Internal Structure of Fish

Amphibians Includes frogs, toads, salamanders, and newts. Ecotherms External fertilization Offspring develop in water and undergo metamorphosis Moist skin without scales

Amphibians Young offspring have gills and 2 chambered hearts. As they grow, they develop lungs and 3 chambered hearts. Some salamanders don’t have gills or lungs, but instead exchange carbon and oxygen through their moist skin.

Amphibians Amphibians have tympanic membranes behind their eyes that pick up sound and transmit it to their ears. Amphibians tend to have good vision and good hearing.

Amphibians Some amphibians produce skin toxins as a defense mechanism Amphibians are good indicator species – they are very sensitive to changes in their environment (pollution).

Amphibians                       

Internal Structure of Frog

Reptiles Includes turtles, crocodiles, alligators, snakes, and lizards Reptiles have thick, dry skin with scales Ectothermic They have 3 chambered hearts

Reptiles Reptiles undergo internal fertilization and most lay eggs. Reptiles can live out of water (snakes, lizards), in water (some turtles), or both (alligators, crocodiles, turtles).

Reptiles Some reptiles are capable of producing toxins (snakes). Most of the molecules in toxins are proteins and enzymes. Causes drop in blood pressure, internal bleeding, muscles stop working (can’t breathe, heart stops)

Reptiles                            

Aves (Birds) Maintain a constant body temperature (Endothermic) Have 2 legs, covered with scales, that are used for walking Forelimbs modified (evolution term) into wings

Aves Birds have different types of feathers: Down feathers – trap air close to the body to keep the bird warm Contour feathers – make body streamlined, provide lift and balance for flying.

Aves Most features are adapted for flight Hollow bones (lighter) Efficient respiratory, digestive, and circulatory systems (steady supply of oxygen and food) Strong chest muscles

Aves

Mammals Have hair Nourish their young with milk Breathe air Have 4 chamber hearts Endothermic

Types of Mammals There are 3 types of mammals: Monotremes Marsupials Placental Mammals

Monotremes Monotremes lay eggs Eggs are similar to reptile eggs There are only 5 species of monotremes Ex: Duckbill platypus,echidnas

Platypus pics

Monotremes

Marsupials Marsupials give birth to very tiny offspring. Once born, offspring climb into its mother’s pouch and nurse almost continually until they’re big enough to leave the pouch Ex: Koalas, Kangaroos

Marsupials                          

Baby Possum Video http://www.youtube.com/watch?v=GKImqLtkeZA

Placental Mammals Offspring develop inside a placenta until they are born. Nutrients, oxygen, and wastes are exchanged between mother and offspring through the placenta Ex: humans, horses, cats, etc.

Placental Mammals