The Animal Kingdom

1. The Animal Kingdom Preparation for Dissection

2. Animals have: Multicellular organisms Eukaryotes have a nucleus and has other organelles No cell walls

3. Invertebrates Invertebrates are animals that do not have a backbone. 95% of animals are invertebrates 11 of 12 phylum of animals

4. Symmetry Radial: Similar parts branch out in all directions from central line (example: starfish) Bilateral: 2 similar halves on each side of central plane (example: earthworm)

5. Invertebrates With no backbone, animals need various methods of support for body Can have exoskeleton-hard covering on outside (exo-)

6. Starfish (Sea Stars) An invertebrate Are carnivores (eat animals such as clams) Suckers grab onto food and mouth balloons out to pull food in.

7. Starfish Continued Have the ability to regenerate arms that they have lost. Move by “walking” along the bottom of the seafloor with their tube feet. Video http://www.schooltube.com/video/46aadd3ebaeb38f2b44b/ http://www.arkive.org/common-starfish/asterias-rubens/video-06.html

8. Terminology for Dissections: Anterior: Front end of a bilateral organism Posterior: Back end of a bilateral organism Dorsal: The top of a bilateral organism Ventral: The bottom of a bilateral organism

9. Earthworms Digestion in the Worm The Pharynx sucks the food into the earthworm Peristalsis pushes the food down the esophagus to the crop for storage. The Gizzard grinds up the food into tiny particles. The tiny particles of food are absorbed through the intestinal wall into the bloodstream The blood then delivers the nutrients(food particles) to the individual body cells.

10. Phylum: Chordata Have a dorsal nerve cord Have notochord, rod of tissue on dorsal side of body Subphylum: Vertebrates Dorsal nerve cord develops into brain and spinal cord Notochord only during embryonic stage, replaced by backbone

11. Classes of vertebrates Fish, amphibians, reptiles, birds, and mammals All but fish spend at least part of their life on land

12. Characteristics of Vertebrates Have endoskeleton: internal skeleton to support large, heavy body. Grows as animal grows Segmented: see in ribs and vertebrae Skin adapted to hold water in body (except fish) Use lungs or gills for gas exchange

13. Reproduction: Fish and amphibians release eggs into water, where fertilization takes place Reptiles, birds, and mammals fertilization takes place inside the female Better chance the egg will be fertilized Mammals give birth to live offspring Many other species have zygotes that develop outside female

14. Fish Classification Ectothermic: body temperature is same as environment (“cold-blooded”) Evolved 550 million years ago Class Osteichthyes: Bony fish, paired fins, jaws Class Chondrichthyes: Cartilage skeleton, jaws, paired fins Class Agnatha: eel-like elongated bodies, no jaws, no paired fins, no bones

15. Class Reptilia Evolved about 300 million years ago, after amphibians went onto land First fully terrestrial organisms, don’t go into water to reproduce

16. Have thick, dry, scaly skin to keep water tight Ectothermic: warms body by absorbing heat from environment

17. Reproduction in Reptiles Oviparity: fertilized egg enclosed in tough protective shell, deposits into safe place in environment- BIG EVOLUTIONARY STEP –No longer needed water to reproduce Nutrition comes from yolk of egg Most reptiles, birds, a few mammals

18. Even greater protection for the young Ovoviviparity: Eggs remain in female until just about ready to hatch. Protects from environment for longer periods of time. Nutrition comes from yolk of egg, not mother

19. Viviparity: The young retained in females body until they are mature enough to be born. No protective shell. Nutrients come from placenta Most mammals do this, a few lizards and snakes

20. Groups of reptiles Reptile classification: 1. Turtles and tortoises 2. Crocodiles 3. Lizards and snakes 4. Tuataras (only 2 living species remain)

21. Class: Aves (Birds) Largest class of terrestrial vertebrates Evolved around 150 million years ago Bodies of birds are well adapted to flight

22. Characteristics of Birds 1. Feathers: for flight and insulation 2. Wings: forelimbs modified into wings for flight 3. Lightweight, rigid skeleton: bones thin walled and hollow 4. Endothermic: maintain own body temperature

23. More….. 5. Respiratory system: need oxygen in lungs, connected to several air sacs 6. Beak: no teeth 7. Oviparity: lay egg in hard shell and kept warm by one or both parents

24. Evolution of Birds Birds evolved at the end of the Jurassic period (150 million years ago) Thought to have evolved from dinosaurs that were small and fast First bird species (Archaeopteryx)

25. Evidence for Evolution Homologous structures: similar features on different organisms that originated from a shared ancestor Example: Forelimbs (wings and arms)

27. Analogous structures: serve identical functions, and look somewhat alike. Different in embryological development Example: Wings of birds and wings of insects

28. Vestigial Structures: Structures that are not used but were used in an ancestor Example: Wings on a flight-less bird

29. Class: Mammalia First ancestors first appeared 300 million years ago First mammals appeared at same time as first dinosaurs Dinosaurs kept mammals small for survival until their extinction

30. Characteristics of Mammals 1. Endothermic: control own body temp 2. Hair: Insulate body to prevent heat loss 3. Divided heart: More efficient at keeping high levels of oxygen in blood 4. Milk: Females produce milk to feed young (mammary glands)

31. Mammals Continued 5. Single jawbone: helpful to identify mammal fossils 6. Specialized teeth: at front to bite, cut, and capture prey. In back to grind and chew

32. 3 Main groups of mammals: Monotremes: Are oviparious (lay eggs) 3 species exist Platypus, 2 species of anteaters Most primitive of all mammals

33. Marsupials: Result of isolation, Australia and New Guinea Are viviparious Time embryo in mother is very short

34. 3. Placental mammals: Viviparious Long period of development inside mother Nourished by placenta 18 orders

35. Some Examples Examples of placental mammals: Bats: use echolocation to navigate (have small eyes and large ears) Order cetacea (whales, porpoises, dolphins)