INVERTEBRATES About 97 percent of all animals are invertebrates.

1. INVERTEBRATESAbout 97 percent of all animals are invertebrates.

2. Introduction to Animals

3. Over a million different types have been identified! • Animals likely evolved from protozoans. Kingdom Protista

4. Section 1 • blastula (596) • ectoderm (596) • endoderm (596) • mesoderm (596) • body plan (598) • asymmetrical (598) • radial symmetry (598) • bilateral symmetry (598) • cephalization (599) • coelom (600) • acoelomate (600) • pseudocoelomate (600) • coelomate (600) • phylogenetic tree (602)

5. Characteristics of Animals All animals share these general features: • heterotrophy, • mobility, • multicellularity, • sexual reproduction, • diploidy, • the absence of a cell wall, • cells organized as tissues, and • blastula formation.

6. heterotrophy, Can’t make their own food… must eat things.

7. mobility, • Animals can swim, crawl, walk, run, and even fly. • Some only move in the larval stage… the sponge

8. multicellularity, • Made up of more then one cell! • Although animals come in a wide range of sizes, the cell sizes are all very similar!

9. sexual reproduction • Almost all animals reproduce sexually by producing gametes. • Unlike the egg cells, the sperm cells of animals have a flagella and are highly mobile.

10. diploidy, adults have two copies of each chromosome, one inherited from their father and one from their mother.

11. the absence of a cell wall, Among the cells of multicellular organisms, only animal cells lack rigid cell walls. The absence of a cell wall has allowed animals mobility that other multicellular organisms do not have.

12. blastula formation In all animals except sponges, the zygote (fertilized egg cell) undergoes cell divisions that form a hollow ball of cells called a blastula.

13. cells organized as tissues Cells within the blastula eventually develop into three distinct layers of cells endoderm, ectoderm, and mesoderm . These layers are called the primary tissue layers because they give rise to all of the tissues and organs of the adult body.

14. tissues tissues are groups of cells with a common structure that work together to perform a specific function.

15. Body Symmetry All animals have their own particular body plan, a term used to describe an animal’s shape, symmetry, and internal organization.

16. 3 body symmetry

17. radial symmetry Animals with radial symmetry have body parts arranged around a central axis.

18. bilateral symmetry Animals with bilateral symmetry have a distinct right and left half, and most display cephalization.

19. body plans Animals have one of three basic body plans: acoelomate, pseudocoelomate, and coelomate.

20. coelom a body cavity, coelom or (SEE luhm), a fluid-filled space found between the body wall and the digestive tract (gut). This space is lined with cells that come from mesoderm.

21. Coelomates are either protostomes or deuterostomes. • Protostomes (first mouth) are coelomates whose embryonic development shows a blastopore associated with a mouth. • Deuterostomes (second mouth) are coelomates whose embryonic development shows a blastopore associated with an anus, with a second opening forming the mouth (hence "second mouth").

22. acoelomate Animals with no body cavity are called acoelomate (ay SEEL oh mayts). The space between an acoelomate’s body wall and gut is completely filled with tissues

23. pseudocoelomate have a body cavity located between the mesoderm and endoderm. Their body cavity is called a pseudocoelom (false coelom)

24. Body plans

25. Segmentation Segmentation in body structure underlies the organization of all advanced animals.

27. Some animals have their bodies divided into segments. This allows them to specialize certain segments, such as for antennae, eyes, claws, etc. Humans, insects, and earthworms are examples of segmented animals.

28. animal phyla There are about 35 animal phyla, which contain an extraordinary range of body forms and body systems. .

29. phylogenetic tree To visually represent the relationships among various groups of animals, scientists often use a type of branching diagram called a phylogenetic tree. It shows how animals are related through evolution

30. Scientists classify animals using several different types of data, which include comparing anatomy and physiology, patterns of development, and DNA.

31. The animal kingdom is divided in two groups: vertebrates and invertebrates

33. Animals are characteristically multicellularheterotrophs whose cells lack cell walls • Animals likely evolved from protozoans. Kingdom Protista

34. At some point during their lives, animals are capable of movement. • In the most commonly encountered animals, this stage is the adult, although some animals (corals) have sessile (nonmobile) adult phases and mobile juvenile forms.

35. Body Cavity and Development • Acoelomate animals (like flatworms and flukes) do not have a coelom (or body cavity) • Pseudocoelomate animals (like roundworms) have a body cavity but it does not develop from splitting of the mesoderm. • Coelomate animals (humans, fish, shrimp) have a body cavity lined with mesoderm cells.

37. Coelomate

38. Coelomates are either protostomes or deuterostomes. • Protostomes (first mouth) are coelomates whose embryonic development shows a blastopore associated with a mouth. • Deuterostomes (second mouth) are coelomates whose embryonic development shows a blastopore associated with an anus, with a second opening forming the mouth (hence "second mouth").

39. Segmented Bodies • Some animals have their bodies divided into segments. This allows them to specialize certain segments, such as for antennae, eyes, claws, etc. Humans, insects, and earthworms are examples of segmented animals.

40. Make a Chart to record notes!

42. Sponges: The Phylum Porifera • These asymmetrical animals have sac-like bodies that lack tissues, and are usually interpreted as representing the most primitive form of animals. • Cells from fragmented sponges can reorganize/regenerate the sponge organism, something not possible with animals that have tissues. • Most zoologists consider sponges as offshoots that represent an evolutionary dead-end. Sponges are aquatic, largely marine animals, with a great diversity in size, shape, and color.

43. Sponges (Phylum Porifera) Sponges are sessile, spending their lives anchored to a solid surface underwater. Most are marine although some live in fresh water. diploblastic; that is, the body wall is made of two layers of cells with a jellylike mesoglea between them; The body wall is perforated with pores (hence the name Porifera) through which water containing food particles is filtered. The water is drawn in through the pores by collar cells like those found in choanoflagellates. Digestion is intra-cellular (inside the cells ). dispersed by small, free-swimming larvae; about 10,000 species known

46. Sponges can reproduce asexually (by budding or from fragments) or sexually. Sponges produce eggs and sperm that are released into a central cavity of the sponge, in which the zygote develops into a ciliated larva. The larval stage is able to move about while the adult is stationary

47. SPONGES

49. Poriferans • don't have mouths; instead, they have tiny pores in their outer walls through which water is drawn. Cells in the sponge walls filter goodies from the water as the water is pumped through the body and out other larger openings. The flow of water through the sponge is unidirectional, driven by the beating of flagella which line the surface of chambers connected by a series of canals. Sponge cells perform a variety of bodily functions and appear to be more independent of each other than are the cells of other animals.