Flashcards in Lecture 30 - Invertebrates I Deck (24)
What is evo-devo?
study of evolutionary developmental biology
What are the 2 aspects of the Genetic Theory of Morphological Evolution?
1. Morphological diversity evolves through alterations in functionally conserved proteins
2. 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
How do Phylum Porifera eat?
-Choanocytes line spongocoel to trap food in collars
What kind of reproductive system do Phylum Porifera have?
(Individuals produce both sperm + eggs)
(Phylum Porifera) Where do gametes arise?
-choanocytes or amoebocytes
(Phylum Porifera) 3 steps of reproduction
1. Eggs are typically retained, sperm carried out osculum by water current
2. Sperm drawn into neighboring individuals
3. 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
(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?
1. Polyp (sessile)
2. Medusa (floating jellies)
What are 3 characteristics of Polyp?
1. Cylindrical, adhere to substratum by aboral end
2. Extend tentacles
3. Wait for prey
What are 2 characteristics of Medusa?
1. 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
What are nomatocystes?
inject poison into pretty after chemo-mechano stimulation
How does symbiosis work between phylum cnidaria and anemone work?
-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?