AnimalKingdomLEC28 Flashcards
do animals have cell walls?
no
how long has kingdom animalia been around?
for billions of years
*has huge diversity of species, but extinct onces are more huge
what are the characteristics of animals?
- multicellular
- heterotrophic
- eukaryotes with layers of tissues
what does animals only have that other kingdoms don’t?
nerve & muscle tissues
how do animals reproduce? what stage dominate their life cycle?
- sexually
- diploid
after a zygote divides, what does it form into?
a ball of cells called blastula
what is a gastrula?
a hollow embryo formed from a blastula
what is a ectoderm & endoderm? which one will develope into the digestive system?
- the outer & inner layers of the embryo when gastrula is formed
- the endoderm
what is the common ancestor of all living animals? when did they evolved?
- a flagellated colonial protist
- about 1.2 bya
what is one of the earliest animals on earth? where were they discovered?
- ediacaran fauna that were soft-bodied & small
- australia
- may included sponges & jellyfishes that dominated the seas for millions of years
what happened during the cambrian explosion 540 mya?
the sudden appearance of animals including predators & preys
*many died in mass extinction
when did coral reefs became the first important marine habitats? what were the dominant terrestrial vertebrates at this time?
- during the mesoic era, 250-65 mya
- dinosaurs
how did our era began?
with the mass extinction of most animals
*cenozoic era, 65 mya to present
what living things diversified rapidly during the cenozoic era?
mammals, insects, & angiosperms
animals can be categorized according to what symmetries?
- radial, divides into mirror images through center
ex. starfishs & sand dollars - bilateral, divides into mirror halves
ex. lobsters & shovels
bilateral symmetric animals have what sides & ends?
- dorsal(top) & ventral(bottom) sides
- anterior(head) & posterior(tail) ends
what is cephalization?
the developement of the head
what are tissues?
collection of specialized cells seperated by membranes
what can tell us a lot about our evolution?
our embryos
*the way our bodies develop can mimic the way we evolve
how many groups of phyla of animals are currently recognized by zoologists?
35
what are the animal phylum porifera?
ex. sponges
basal animals that lacks true tissues
*different from other animals & the first to split off
what are the animal phylum eumetazoa?
animals with true tissues
*like us
what are the animal phylum cnidaria?
ex. jellyfishes
diploblastic(has 2 layers of tissues) animals
most animals are in what clade?
bilateria
*they are triploblastic
what are the 3 branches of bilateria?
- acoelomates, no cavities
ex. animal version of non-vascular plants, planarians flatworms ediacaran fauna - pseudocoelomates, simple cavities
ex. roundworms/nematodes - coelomates, true body cavity called coelom
ex. earthworms
what are the 2 branches of coelomates?
- protostomes - annelid worms, mollusks, & arthropods
- deuterostomes - echinoderms & chordates
ex. starfish & angel fish
what do arthropods shed during molting?
ex. 17 years locust, crabs
their exoskeletons
