Unit 6: Cycles and Animal Ecology Flashcards
What are the five characteristics of animals?
- Eukaryotes
- Multi-cellular
- Lack cell walls
- Heterotrophic
- Blastula during embryonic development
How do we say “toward the head”?
Anterior
How do we say “toward the tail”?
Posterior
How do we say “back side”?
Dorsal
How do we say “belly side”?
Ventral
What do we call an anterior concentration of sense organs?
Cephalization
What is a blastula?
A hollow ball of cells
The blastula pinches inward (invagination), eventually forming _______
Gastrula
What are the three germ layers formed during invagination? (blastula –> gastrula)
Endoderm
Mesoderm
Ectoderm
What does the endoderm become?
The gut
What does the mesoderm become?
The inside bits
What does the ectoderm become?
Skin
What are the advantages of segmentation?
- allows greater body mobility
- allows for specialization of body parts
What is the body cavity called?
Coelem
What do we call the layer that lines the body cavity and gut and covers the internal organs?
Peritonium
What is a pseudocoelemate?
An organism with the coelem but no peritonium
What are the characteristics of sponges?
- No true tissue
- Cellular digestion
- Asymmetry
What are the characteristics of sponges?
- No true tissue
- Cellular digestion
- Asymmetry
What are the characteristics of Cnidaria (hydra)?
- Radial symmetry
- Two germ layers
- Sac gut
What are the two types of guts?
- Sac gut (one opening)
- Tube gut (two openings)
What are the characteristics of Platyhelminthes? (flatworms)
- Three germ layers
- Internal organs and muscles
- No coelem
- Cephalization
What are the characteristics of Nematodes (roundworms)?
- Pseudocoelems
- Tube-within-a-tube (mouth and anus)
