Biodiversity - Parazoa and Radiata Flashcards
what is the ancestral animal?
definition, example
the organism that all animals evolved from, its the colonial heterotrophic flagellate.
what is colonial heterotrophic flagellate?
ancestral animal, its very simple and cant make its own food, has to take it in
when did sponges brake off?
they were the first animal to brake off from the ancestral animal
how are modern phylogentic trees made?
using molecular techniques, sequencing of SSU-rRNA
what are the 4 main branch splits in the phylogentic tree?
- gastrulation vs no gastrulation
- Radiata symmetrical vs bilaterally symmetrical animals.
- Patterns of development of the body (protosoemes and deutrosomes)
- Specific type of larvae vs those who shed then skin
what is the first branch of the tree?
the first split
seperates parazo from everything else
what are the differences between radial vs bilateral symmetry?
the second split
- 2 sides vs 4 sides
- 2 tissue layers vs 3 layers
- passive lifestyle vs active lifestyle (sensory organs)
difference between protostome and deuterostome
split 3
- Pattern of cleavage in early embryos
- Cell fate during early development
- Coelom formation
- Fate of Blastopore
what is the coelom (body cavity)?
Gap inside animal but its not the gut, in between the endoderm and ectoderm
what is a parazoa
sponge
features of a sponge
4
- asymmetrical
- no gastrulation
- no tissues
- very simple
- hermaphrodites
- externally reproduce
examples of radiata
jelly fish, anemones
radiata features
- radial symetry
- 2 tissue layers
- polyp or medusa
- simple form
what is the difference between poylp and medusa radiata?
mouth is at different ends
what are cnidocytes (tenticles)?
used in defence and capture of prey
