Chapter 32 & 33
Kingdom Animilia
- Over 1.5 million species
- Estimated 73 million
- 35 Phylums
- Over half are insects
- More similarities within animal genomes than other kingdoms
Characteristics
- Multicellular
- Lack of cell wall
- Sexual reproduction
- mobile sperm
- larger non-motile egg
- Nervous Tissue
- Complexity
- Responsiveness
- Hox Genes
- Special clusters of genes associated with the planning of the body
Metazoans
- All animals
- Multicellular animals
- Paratoans
- Sponges
- Eumetazoans
- "true" multicellular animals
Classification/Systematics
- Old
- Morphology
- Embryotic Development
- Recent
- Molecular genetics
Body Plans
Morphological and Developmental Features
- Body Symmetry
- Number of tissue Layers
- Patterns of Embryonic development
Symmetry
- Eumetazoa
- Divided by symmetry
- Radiata
- Radial symmetry
- Often Circular or tubular
- Bilateria
- Bilateral symmetry
- Dorsal
- Back
- Ventral
- Front
- Anterior
- Posterior
- cephalization
- enlarged head
Tissues
- Metazoa
- all animals
- divided on weather or not they have specialized tissues
- Parazoa
- Porfera
- sponges
- may have distinct cell types
- Porfera
- Enmetazoa
- more than one type of tissue
- organs
- all other animals
Germ Layers
- Radial
- 2 layers
- Diploblastic
- endoderm
- extoderm
- Bilateral
- 3 layers
- Triploblastic
- endoderm
- extoderm
- mesoderm
Embryonic Development
- Protostome
- Blastopore becomes mouth
- cleavage is determinate
- fate of embryonic cells are determined early
- Deuterostome (second opening)
- Blastopore becomes anus
- cleavage is indeterminate
- each cell produced by early cleavage can develop into a complete embryo
Other Morphological Characteristics
Used in classification
- Presence or absence or coelom