Protostomes Flashcards
General structure and behavioral characteristics of animals
- multicellular
- lack cell walls
- heterotrophic
- motile at some point in life
- reproduce sexually or asexually
- cell membranes are in direct contact with eachother
- have excitable tissues (muscles and nerves)
- have perception and response to environment
What is believed to be the origin of all animals?
Colonial, flagellated protist from the precambrian era
What are the types of symmetry
Radial and bilateral
What is radial symmetry
Body parts arranged around a central axis
What is bilateral symmetry
Mirrored along midline
What is the body plan of an acoelomate(flat worm)
- Hollow has no body cavity
- no divide between gut and body wall
What is the body plan of a pseudocoelomate (round worm)
- fluid filled space between endoderm and mesoderm
- slightly compartmentalized
- psedocoelom forms between the gut and the body wall
What is the body plan of an coelomate
- has true coelom
- has body cavity lined by peritoneum which is derived from the mesoderm
- folds of membrane tissues (mesenteries) surround inner organs
- complete separation between gut and body wall
What are the functions of a coelomate body cavity
- used for the transportation of nutrients and products of metabolism
- serve as a hydrogen static skeleton
- provides space for the functioning of organs
What are tissues
Groups of similar differentiated cells that are specialized for particular functions
What are the 3 primary germ layers
1) endoderm
2) mesoderm
3) ectoderm
What does the endoderm form
Form the lining of the gut
- is the innermost layer
What does the mesoderm form
Forms the muscles of the body wall and other structures between the gut system and the external covering
- inbetween layer
What does the ectoderm form
Forms the external covering/skin and the nervous system
- outermost layer
What is a blastula
The hollow organ stage of development in which the organ becomes a hollow sphere through multiple rounds of division where the organs will develop
What is the gastrula
The stage in development in which the 3 germ layers are made
What are characteristics of a protostomes
- develop mouth first
- go through spiral cleavage
- mesoderm differentiates near the blastopore
- forms a schizocoelom
What are characteristics of a deuterostome
- develop anus first
- have radial cleavage
- mesoderm forms from out pocketings of archentron
- forms an enterocoelom
What is cleavage? And it’s 2 types?
Cleavage is the mitotic cell divisions of the zygote to produce a blastula
- spiral cleavage
- radial cleavage
What is segmentation
The production of body parts and some organ systems in repeating units based on what an animal needs to live
What is some evidence of segmentation
- vertebral column
- ribs
- muscles in abdomen
- limbs
What are the 2 different animal molecular phylogeny divisions
- parazoa
- Eumetazoa
