Lecture 30 - Invertebrates I Flashcards
What is evo-devo?
study of evolutionary developmental biology
What are the 2 aspects of the Genetic Theory of Morphological Evolution?
- Morphological diversity evolves through alterations in functionally conserved proteins
- Changes occur through mutations in promoter sequences of regulatory genes + their target genes that participate in developmental pathways
What is a transcription factor?
protein that binds to specific sequences in the promoter of a gene
What does a transcription factor do?
o Controls transcription of genetic info from DNA to RNA
3 Classes of Phylum Porifera
(sponges)
- Glass
- Demosponges
- Calcareous
How do Phylum Porifera eat?
- Suspension feeders
- Choanocytes line spongocoel to trap food in collars
What kind of reproductive system do Phylum Porifera have?
-Sequential hermaphrodites
Individuals produce both sperm + eggs
(Phylum Porifera) Where do gametes arise?
-choanocytes or amoebocytes
(Phylum Porifera) 3 steps of reproduction
- Eggs are typically retained, sperm carried out osculum by water current
- Sperm drawn into neighboring individuals
- fertilize eggs in mesophyll
Sponges are capable of extensive ________
regeneration (replacement of lost parts)
(Phylum Porifera) Defense
Sponges produce variety of bioactive metabolites (antibiotics)
(Phylum Porifera) What cells could be rudimentary sensory organs?
- Globular cells may represent rudimentary sensory organs
- Metazoans were already in possession of proto-neural cells
4 classes of Phylum Cnidaria
- Hydrozoa
- skypozoa
- cubizoa
- anthozoa
(Phylum Cnidaria) basic body plan
- sac with central digestive compartment (gastrovascular cavity)
- single opening to cavity functions as both mouth and anus
(Phylum Cnidaria) What are the two variations in body plans?
- Polyp (sessile)
2. Medusa (floating jellies)
What are 3 characteristics of Polyp?
- Cylindrical, adhere to substratum by aboral end
- Extend tentacles
- Wait for prey
What are 2 characteristics of Medusa?
- Flattened, inverted versions of polyps
2. Drift passively by contracting bell-shaped body
Must Phylum Cnidaria exist as either polyp or medusa?
- some exist as polyps
- some exist as medusas
- others pass sequentially through both stages in life cycle
How do phylum cnidaria eat?
- Cnidocytes on tentacles for defense/prey-capture
- carnivores
What are nomatocystes?
inject poison into pretty after chemo-mechano stimulation
How does symbiosis work between phylum cnidaria and anemone work?
- mutual symbiosis
- Fish defends host, uneaten food/feces feed anemone
- Avoids being stung via sugar-based mucous coating
Epidermal + gastrodermal cells have ______________
contractile fibers of bundled microfilaments
Where did true muscles appear first?
triploblastic animals
(Phylum Cnidaria) How are movements controlled?
- non-centralized nerve net
- Associated with simple, radially distributed sensory receptors
