Exam 4 Flashcards
What types of organisms make up subkingdom Eumetazoa?
Segmented body plans, bilaterally symmetrical organisms, possess an internal body cavity
Which adaptations contribute to improved motility?
Segmentation, internal body cavity, bilateral symmetry
What stage of embryo development consists of a simple hollow ball of cells?
Blastula
What is the percentage of animal species with backbones?
1%
Do all animals with bilateral symmetrical body plans have body cavities while not all animals with body cavities are bilaterally symmetrical?
false
What phylum has pseudocoelmates?
Nematoda
Which phyla have segmented body plans?
arthropoda, annelida, chordata, mollusca, echnodermata
What is made possible by an internal body cavity?
Improved embryonic development, improved organ efficiency, improved motility
What are the characteristics of protostome development?
The first opening of the blastospore becomes the oral end, early cell division is spiral, cells in early development are fixed early (Determinate), mesoderm forms from endodermal cells near the blastospore
What stage of animal development do the primary germ layers begin to differentiate?
Gastrula
In coelomates, where does the coelom form?
forms entirely withing the mesoderm
In psudocoelomates, where does the psudocoelom form?
between the endoderm and mesoderm
Which phyla contain coelomates?
Mollusca, echnodermata, annelida, chordata, arthropoda
Where is the dorsal end?
top/back
Where is the ventral end?
bottom, stomach
Where is the anterior end?
front/head
Where is the posterior end?
back/tail
Process during animal development whereby cells divide and get progressively smaller with each round of division
Cleavage