Lost World
1.muticelled
2.heterotrophs
3.aerobic respiration
4.reproduce asexually and sexually
5.motile during part of life cycle
6.have stages of embryonic development
embryonic cells give rise to primary tissue layers called the ectoderm, endoderm and
usually mesoderm
these tissue layers give rise to all tissues and organs of body
7.eukaryotic
Body symmetry
May be radial symmetry or bilateral symmetry
Radial symmetry all body parts arranged regularly around a central axis
Like spokes of a bike wheel
Ex. Hydra
Bilateral symmetry have a right and left half that are mirror images of each other
Seen in more advanced animals
Cephalization have concentration of sensory structures and nerves and brain region
In head area
Type of Gut
Gut is a tubular or saclike region in the body in which food is digested, then absorbed into the internal environment
Saclike guts have one opening for taking in food and expelling residues
Tubelike (complete) digestive system has an opening at two ends called mouth
And anus
Different parts of system have specialized functions such as preparing, digesting
And storing materials
Types of Body Cavities
May be of three types: coelom, pseudocoel, acoelomate
Acoelomate- tissues fill in region between gut and body wall
No coelom
pseudocoel body cavity with no peritoneal lining
Example:
Coelom area between gut and body wall with unique tissue lining called ___________
Lining encloses organs and helps hold them in place
Advantage: favors increase in size and activity by
Segmentation
repeating series of body units that may or may not be similar to one another
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