Zoology

1. Zoology An Introduction

2. Zoology • Study of animals • In this class- Important Kingdoms- Protista- some, unicellular, animal-like organisms(protozoans) considered to be evol. precursors to animals ANIMALIA- are ANIMALS • Latin “zoa” or “zo”- means animal

3. Kingdom Protista • Single celled • Eukaryotic • Ingest or produce food • Some animallike

4. What is an Animal? Are members of Kingdom Animalia Are multicellular Are Eukaryotic Are Heterotrophs Lack cell walls Usually have a method of movement Most reproduce sexually Require oxygen

5. What is an Animal? Multicellular: Having more than one cell Eukaryotic: Organisms whose cell contain a nucleus Heterotroph: Organisms that obtains energy from the foods it consumes; also called a consumer.

6. 2 Types of Animals Invertebrates: Animals that do not have a backbone or a vertebral column Vertebrates: Animals that has a vertebral column, or backbone

7. What Animals Do to Survive Animals carry out the following essential functions: 1. Feed 2. Respire 3. Circulation 4. Excrete 5. Respond 6. Move 7. Reproduce

8. Essential Functions Respiration: Whether they live in water or on land, all animals respire, which means they take in oxygen and give off carbon dioxide. Some can rely on diffusion of these substances through their skin Most have evolved complex tissues and organ systems for respiration

9. Essential Functions Circulation: transport of nutrients and wastes Many aquatic animals (ex: aquatic worms) rely solely on diffusion to transport oxygen & waste. Larger animals have some kind of circulatory system to move materials around within their bodies.

10. Essential Functions Excretion: releasing wastes A buildup of ammonia & other nitrogenous wastes would kill an animal Animals have excretory system that either eliminates ammonia quickly or converts it into a less toxic substance(uric acid) that is removed from the body.

11. Essential Functions Response:Animals respond to events in their environment using specialized cells called nerve cells. Some nerve cells are receptors that respond to sound, light, and other stimuli The arrangement of nerve cells in the body changes dramatically from phylum to phylum Simple animals- nerve cells, nerve net Complex- nervous systems

12. Essential Functions Movement: Some animals live their entire lives attached to a single spot (sessile) Most are motile meaning that they move

13. Essential Functions Reproduction: Most reproduce sexually by producing gametes. Maintains genetic diversity in populations Helps species evolve when the environment changes Many reproduce asexually & allows to increase numbers rapidly (inverts.)

14. Body Plans of Animals Symmetry: balance in body proportions 3 Types Bilateral: can be divided only one way to produce mirror image halves Asymmetrical- Irregular shape Radial symmetry: can be divided along any plane to produce 2 halves which look alike

15. Symmetry Asymmetrical: Has no definite shape.

16. Symmetry Radial Symmetry: Body is arranged in a circle like the spokes of a wheel.

17. Symmetry Bilateral Symmetry: If divided lengthwise in half, both sides will match.

18. Bilateral Symmetry Includes worms, insects & vertebrates Have external body parts that repeat on either side of the body

19. What type of symmetry?

21. Body arrangements: • anterior: head region(front on upright man) • b. posterior: tail region (back on upright man) • c. dorsal: back or top • d. ventral: abdomen(belly) or bottom

22. Anatomical Terms (cont) • Medial - close to the middle • Lateral • Close to the side or movement away from middle • Distal • Away from the main part • Proximal • Close to the main part

23. Anatomical Terms (cont) • Oral • End with the mouth • Aboral • Opposite end of the mouth • Cephalic • Toward head • Caudal • Toward tail

24. Cephalization-concentration of sense organs- developed nervous system- “formation of head"  

25. How does this happen????

26. Embryonic Development STEP 1     STEP 2  Zygote cleaves to become blastula and then forms gastrula. The blastopore of the gastrula can become either the mouth or the anus of the organism

27. Protostomes vs. Deuterostomes • Protostome- “first mouth” Blastopore becomes the mouth. Ex-Annelids, Mollusks and arthropods • Deuterostome- “second mouth” Blastoporebecomes anus. Ex-echinoderms, hemichordates,chordates

28. a. Ectoderm •  becomes nervous system, epidermis of the skin, pituitary, lens of eye(outside layer) b. Mesoderm •  becomes muscles, skeleton, notochord, circulatory system, kidney, reproductive system (middle layer) c.  Endoderm •  becomes lining of digestive tract, liver, pancreas, epithelial lining of lungs, many endocrine glands (inside layerdigestive tract) Embryonic Development • As embryo develops, three germ layers form:

29. Body Cavities a. Acoelomates- no body cavity lined with mesoderm • EX: flatworms

30. b. Pseudocoelomates- partial body cavity lined with mesoderm • “Tube within a tube” body plan • EX: roundworms, rotifers

31. c. Coelomates- true body cavity lined with mesoderm • EX: all other animals

32. Advantages of a body cavity (coelom or pseudocoelom): • Fluid in cavity helps distribute food, wastes, hormones, etc. from one end of animal to the other • Better distribution allows animal to grow larger • A place to put things, like new organs

33. THE ANIMAL KINGDOM OVERVIEW • Invertebrates-no backbone • Vertebrates or Chordates-backbone

34. Checkpoint • What are the main characteristics all animals share? • Evidence suggests that animals evolved from ___________. • What are the three animal body types? • What are the three germ layers? • What is the difference between a protostome and a deuterostome?

35. The End