Exam Questions and CORRECT Answers
Be familiar with the common characteristics of animals. - CORRECT ANSWER --
Multicellular heterotrophs
- cells lack cell walls
-most have nerves, muscles, and capacity to move at some point in the life cycle
- able to reproduce sexually
- specialized sensory structures and nervous system
- cells exist in extensive extracellular matrix
- unique cell junctions
What type of life cycle do all animals show? - CORRECT ANSWER - gametic
What is the most likely ancestor of animals? - CORRECT ANSWER - choanoflagellates
What are the 3 major features that were traditionally used to classify animals? Know the
different variations on these 3 major features. - CORRECT ANSWER - 1. Tissues
- metazoa
- parazoa
- porifera (sponges)
- eumetazoa
2. Body Symmetry
- radial symmetry
- bilateral symmetry
3. Specific features of embryonic development
- protosome
- deutrosome
,Be able to draw/identify the phylogenetic tree based off those three major features. - CORRECT
ANSWER - See chapter 26 phylogeny tree
What are the features of protostome and deuterostome development? - CORRECT
ANSWER - Protostome:
- spiral cleavage
- cleavage is determinate
- blastopore becomes mouth
Deutrostome:
- radial cleavage
- cleavage in indeterminate
- blastopore becomes anus
What is the focused gene for molecular analysis used in animal diversity? - CORRECT
ANSWER - Compare similarities between DNA and ribosomal RNA of animals
Sometimes focus on small subunit ribosomal RNA
What are the 2 new invertebrate clades that resulted from molecular analysis of the rRNA region
of the genome? - CORRECT ANSWER - Ecdysozoa:
- named for ecdysis (molting)
- nematodes, arthropods, and a few other minor phyla
Lophotrochozoa:
- named for the lophophore (feeding tentacles) and trochophore larva
- mollusks, annelids, and several other phyla
For this chapter, you should know each of the phylum names (13 total phyla) that are the end
points of the phylogenetic tree of invertebrates. You should also be able to be able to draw the
tree and know the major traits that divide the clades on the tree. - CORRECT ANSWER -
1. Phylum Porifera
2. Phylum Cnidaria
,3. Phylum Ctenphora
4. Phylum Platyhelminthes
5. Phylum Rotifera
6. Phylum Bryozoa
7. Phylum Brachiopoda
8. Phylum Mollusca
9. Phylum Annelida
10. Phylum Nematoda
11. Phylum Arthropoda
12. Phylum Echinodermata
13. Phylum Chordata
You should also be able to identify important features of each of the phyla. (type of gut, type of
tissue, presence or absence of a brain, internal vs external fertilization, etc...) - CORRECT
ANSWER - 1. Phylum Porifera
2. Phylum Cnidaria
3. Phylum Ctenphora
4. Phylum Platyhelminthes
5. Phylum Rotifera
6. Phylum Bryozoa
7. Phylum Brachiopoda
8. Phylum Mollusca
9. Phylum Annelida
10. Phylum Nematoda
11. Phylum Arthropoda
12. Phylum Echinodermata
13. Phylum Chordata
1. Phylum Porifera - CORRECT ANSWER - - sponges
, - loosely organized and lack tissues
- multicellular with several types of cells
- 8,000 species, mostly marine
- no apparent symmetry
- adults sessile, larvae free-swimming
- water drawn through pores into spongocoel
- flows out through osculum
- choanocytes line spongocoel
- mesohyl between choanocytes and epithelial cells
- reproduce sexually and asexually
2. Phylum Cnidaria - CORRECT ANSWER - - radial symmetry
- mostly marine
- two embryonic germ layers
- first trade with true tissues
- gastrovascular cavity got extracellular digestion
- two forms: sessile polyp and motile medusa
- cnidocytes contain nemotocysts
-simple muscles and nerves
3. Phylum Ctenophora - CORRECT ANSWER - - radial symmetry
- mostly marine
- two embryonic germ layers
- first trade with true tissues
- gastrovascular cavity got extracellular digestion
- comb jellies
- less than 100 species
- first complete gut