Animal diversity

a presentation about the animal diversity ;)

1. Animal Diversity

2. Extends far beyond humans and other animals we may encounter The Animal Kingdom Figure 32.1

3. Animal are multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers Several characteristics of animals Sufficiently define the group

4. Animals are heterotrophs That ingest their food Nutritional Mode

5. Animals are multicellular eukaryotes Their cells lack cell walls Cell Structure and Specialization

6. Most animals reproduce sexually With the diploid stage usually dominating the life cycle After a sperm fertilizes an egg The zygote undergoes cleavage, leading to the formation of a blastula The blastula undergoes gastrulation Resulting in the formation of embryonic tissue layers and a gastrula Reproduction and Development

7. Early embryonic development in animals Zygote Cleavage Eight-cell stage Cleavage Blastula Cross section of blastula Blastocoel Blastocoel Gastrula Gastrulation Endoderm Ectoderm Blastopore

8. Early members of the animal fossil record Include the Ediacaran fauna Neoproterozoic Era (1 Billion–524 Million Years Ago)

9. The Cambrian explosion Marks the earliest fossil appearance of many major groups of living animals Is described by several current hypotheses Paleozoic Era (542–251 Million Years Ago)

10. During the Mesozoic era Dinosaurs were the dominant terrestrial vertebrates Coral reefs emerged, becoming important marine ecological niches for other organisms Mesozoic Era (251–65.5 Million Years Ago)

11. The beginning of this era Followed mass extinctions of both terrestrial and marine animals Modern mammal orders and insects Diversified during the Cenozoic Cenozoic Era (65.5 Million Years Ago to the Present)

12. Animals can be categorized According to the symmetry of their bodies, or lack of it Some animals have radial symmetry Like in a flower pot Radial symmetry. The parts of a radial animal, such as a sea anemone (phylum Cnidaria ), radiate from the center. Any imaginary slice through the central axis divides the animal into mirror images. Symmetry

13. Bilateral symmetry. A bilateral animal, such as a lobster (phylum Arthropoda ), has a left side and a right side. Only one imaginary cut divides the animal into mirror-image halves. Some animals exhibit bilateral symmetry Or two-sided symmetry

14. Based on certain features seen in early development Many animals can be categorized as having one of two developmental modes: protostome development or deuterostome development Protostome and Deuterostome Development

15. In protostome development Cleavage is spiral and determinate In deuterostome development Cleavage is radial and indeterminate Cleavage Protostome development (examples: molluscs, annelids, arthropods) Deuterostome development (examples: echinoderms, chordates) Eight-cell stage Eight-cell stage Spiral and determinate Radial and indeterminate (a) Cleavage. In general, protostome development begins with spiral, determinate cleavage. Deuterostome development is characterized by radial, indeterminate cleavage.

16. In protostome development The splitting of the initially solid masses of mesoderm to form the coelomic cavity is called schizocoelous development In deuterostome development Formation of the body cavity is described as enterocoelous development Coelom Formation Figure 32.9b Archenteron Blastopore Mesoderm Coelom Blastopore Mesoderm Schizocoelous: solid masses of mesoderm split and form coelom Enterocoelous: folds of archenteron form coelom Coelom (b) Coelom formation. Coelom formation begins in the gastrula stage. In protostome development, the coelom forms from splits in the mesoderm ( schizocoelous development). In deuterostome development, the coelom forms from mesodermal outpocketings of the archenteron ( enterocoelous development).

17. In protostome development The blastopore becomes the mouth In deuterostome development The blastopore becomes the anus Fate of the Blastopore Figure 32.9c Anus Anus Mouth Mouth Mouth develops from blastopore Anus develops from blastopore Digestive tube