Chapter 9: Architectural Pattern of an Animal Metazoans

1. Chapter 9: Architectural Pattern of an AnimalMetazoans

2. 32 Phyla of multicellular animals • Survivors of 100 phyla from the Cambrian explosion 600 million years ago.

3. Heterotrophy • Cannot make own food • Filter feed in ocean or find food

4. Mobility • Muscle cells • Swim, crawl, walk, run and fly • Some sessile(do not move)

5. Multicellularity • Daphnia to large whale • More than one cell

6. Organization and Complexity Metazoa or multicellular animals evolved greater complexity by combining cell into larger units Cell – tissue – organs – organ systems Parenchyma – main functional cells Stroma – supportive tissues

7. Segmentation Also called metamerism Common feature of animals Serial repetition of similar body segments along the longitudinal axis of body (parts repeat) Each segment is called a metamere or somite.

8. Allows for more mobility and complexity of structure and function Examples include annelids, chordates and arthropods ( Worms, vertebrates and insects)

9. Diploidy • Adults have 2 copies of each chromosome • One from mother and one from father

10. Sexual reproduction • Gametes from 2 separate parents • Can also see asexual reproduction in the animal kingdom – budding – all genetic information comes from on parent

11. No cell wall - mobility • Eukaryotic – nucleus and other membrane bound organelles

12. Blastula Formation • Zygote forms blastula • Hollow ball of cells • Develop into 3 distinct layers • Ectoderm/endoderm/mesoderm • These layers give rise to all other tissues/organs

13. Zygote - Gastrula • Found in all animals but sponges • One cell – 8 cells – blastula – layers • Process is called cleavage • Takes 3 hours to reach blastula • Second process the blastula begins to collapse inward while cells move to position - gastrulation

14. Cell begin to vary in size and form the 3 primary tissues • Now at embryo stage • Evidence of common ancestor

15. Blastopore Opening to the gut where the inward bending begins First opening that forms in the gastrula

16. During embryonic development germ layers become differentiated into four tissues. • Epithelial • Connective • Muscular • Nervous

17. The development of an animal embryo follows one of two different patterns • Protostome – The blastopore develops into mouth-most invertebrates • Deuterostome-The blastopore develops into the anus – Echinoderms and Chordates

18. Animal Body Plans • Limited by ancestral history. • Shaped by habitat and way of life.

19. Animal Symmetry • Arrangement of body parts with reference to same axis of body. • Most animals have symmetry. • Sponges do not. • Asymmetrical

21. Asymmetry • Without symmetry

22. Spherical Symmetry • Any plane passing through the center divides the body into mirrored halves. • Protozoa

23. Radial Symmetry • Divided into similar halves by more than two planes passing through one main axis. • Tubular, vase or bowl shape. • Some sponges, Hydras, Jellyfish

25. Biradial Symmetry • Some parts are paired rather than radial.

26. Echinoderms • Larvae are Bilateral • Become secondarily radial as adults.

27. Bilateral Symmetry • Divided along a sagital plane into two mirrored portions-right and left halves • Better fitted for directional movement-forward • Associated with cephalization

30. Sagittal • Transverse • Frontal • Draw your own squirrel and label now

31. Animal Body Regions • Anterior – head end • Posterior – tail end • Dorsal – back side • Ventral – front or belly side • Medial – midline of the body • Lateral – the side of body

32. Distal – farther from the middle of the body • Proximal – parts near a reference point • Pectoral – chest region • Pelvic – hip region or area supported by hind legs

34. Body Cavities • Bilateral animals can be grouped according to their body cavity type or lack of body cavity. • Coelom – in more complex animals the main body cavity. • A fluid filled space that surrounds the gut.

35. Provides a “tube within a tube” arrangement. • Allows body flexibility. • Provides a space for visceral organs or internal organs.

36. Greater size and complexity – more cells exposed to surface exchange. • Hydrostatic skeleton in many animals. • Worms

37. Coelom forms differently in protostomes and deuterostomes • Some inverts or protostomes lack a coelom

38. Cephalization • Differentiation of a head or head region. • Bilaterally symmetrical animals. • Most efficient position for sensing the environmental and responding to it.

39. THE END Time to write your summary!!