Animal diversity Flashcards
What are the key traits of animals?
Eukaryote multicellular heterotrophic muscle and nervous system lack cell walls unique cell junctions
What are the three cell junctions?
Tight junctions
desmosomes
Gap junctions
What are desmosomes?
Anchoring proteins, fasten cells into sheets
What are gap junctions?
Communication junctions
What are tight junctions?
plasma membrane of neighbour vcelss bound
What are homeobox genes?
large family of similar genes that direct the formation of many body structures during early embryonic development. A homeobox is a DNA sequence found within genes that are involved in the regulation of patterns of anatomical development
Hox genes?
Hox genes code for proteins that attach to molecular switches on DNA, turning other genes on and off - coded for by homeobox
What is the blastula?
Hollow ball of cells in embryo development
What is gastrulation?
When one end of the ball folds inwards and expands to fill blastocoel, makes embryonic tissue layers
What is the blastocoel?
fluid-filled cavity that forms in the animal hemisphere
Where did animals originate?
choanoflagellate ar ether closest living ancestors
What are choanoflagellate?
Colonial heterotrophic flagellate forst to evolve. single collar of. macromolecule used for feeding
What are the characteristics of protostome development?
spiral and determinate
mesoderm splits onto solid maps to form coelom
mouth develops from blastopore
What are the characteristics of deuterostome?
radial and indeterminate
Coelom forms from fold of archenteron
blastopore forms the anus
What are the different tissue layers?
Ectoderm
Endoderm
Mesoderm
