kingdom animalia Flashcards
what characteristics are used to classify animals?
presence or absence of backbone levels of organization number of body layers symmetry and body plans body cavity segmentation movement reproduction
what is an invertebrate?
animals that do not have a backbone
what is a vertebrate?
animals that have an internal skeleton and backbone
what do most animals develop during the early stages of embryonic development?
three layers of cells
ectoderm
mesoderm
endoderm
what is the ectoderm?
outer layer (ie skin)
what is the mesoderm?
middle layer (ie muscles, blood)
what is the endoderm?
inner layer (ie organs)
what are the three body plans?
asymmetry
radial symmetry
bilateral symmetry
what is asymmetry?
irregular body shape
what is radial symmetry?
body plan can be divided along any plane into equal halves
what is bilateral symmetry?
body plan can be divided along one plane into equal halves
what are the four features of chordates?
a notochord
a dorsal nerve cord
gill slits
tail
what is a notochord?
(aka rod of cartilage) runs along the length of the body- usually replaced by bone (spine) during fetal development
what is the dorsal nerve cord?
tube shaped cord that becomes the brain and spinal cord
what are gill slits?
in the pharynx/ throat
in terrestrial vertebrates they appear only in the embryonic stage
