biodiversity of animals Flashcards
phylum
a taxonomic rank below kingdoms and above class
taxonomist
biologists that identify and grp organisms according to their characteristics
body plans: invertebrates (6)
STOB CC 1=symmetry 2=tissue layers 3= openings in gut 4= blood system 5=cephalisation 6= coelom
types of symmetry in terms of body plans
1= asymmetrical (no symmtry) 2= symmetrical (yes: 2)
types of symmetry (2)
1= radial (circle, around cntr) 2= bilateral (only 2 mirror halves)
what is meant by radial symmetry
a body plan in which the body parts repeat around a cntr of the body, body can be divided into more than 2 equal halves
what is meant by bilateral symmetry
a body plan in which a body can only be cut into 2 mirror halves (usually due to cephalisation that the body cannot be cut into 2)
which phylum are asymmetrical. Give the organism name
porifera = sponges
what are the 6 phylums
POor CNidaria. flat help ANNE ARTCHer
Porifera Cnidaria Plathelminthesis Annelida Arthropoda Chordata
which phylum has radial symmetry. Give the organism name (egs)
Cnidaria- jelly fish and blue bottles
which phyla has bilateral symmetry. Give eg organism names (4)
1- plathelminthesis = flat worms
2- annelida = segmented worms
3- arthropoda = jointed legs (spiders. crabs, crustaceans)
4- chordata = vertebrates (mammals, birds, fishes, frogs, reptiles)
what are the 3 germ/tissue layers in embryonic dev and where are they
1= ectoderm:outer layer 2= endoderm :inner layer 3= mesoderm : layer betw ecto and endoderm
what does the ectoderm develop into (2)
the outer protective layer
- sense organs
- nervous system
what does the endoderm dev into
the linning of the digestive system
what does the mesoderm dev into (6)
1- internal organs 2- bone 3- blood 4- repro organs 5- cartilage 6- lymphatic system
what are animals that have only 2 germ layers called
diploblastic - only ecto and endoderm layer
sep by mesolglea
what is mesoglea
non cellular jelly like layer that sep endo and ectoderm layers of diploblastic animals
- also the tissue jelly fish (cnidaria) that functions as hydro static skeleton
what are animals with only 3 germ layers called
triploblastic
which phylums are diploblastic (1)
cnidaria
which phylums are triploblastic (4)
1- platyhelminthesis
2- annelida
3- arthropoda
4- chordata
def sessile
organisms that are immobile and attached to one place for life
- sponges (porifera)
what are the advantages of organisms that have bilateral symmetry
- allows animal to move thro enviro in 1 direction
- can focus senses on this direction
- this focus helps with feeding and avoiding predators
def cephalisation
the accumulation/ concentration of nerve cells at the anterior end which leads to the dev of a head and central nervous system
phyla without cephalisation tip: they dont have bilateral symmetry
1- porifera= asymmetrical
2- cnidaria = radially symmetrical