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
phyla with cephalisation , tip: they have bilateral symmetry
1= plathelminthesis 2= annelida 3= arthropoda 4= chordata
def coelom
internal fluid filled cavity that lies betw ectoderm and endoderm (betw digestive tract and outer body wall) and dev in mesoderm in triploblastic organisms
what fluid fills the coelom and what is its purpose
coelomic fluid = acts as transp medium for substances
what is the purpose of a coelom (4)
1- to seperate the digestive tract from body wall
2- ensures that each functions independently of each other
3- acts as hydroskeleton
4-allows animal to grow by prov space for organs to dev
what are 3 categories that triploblastic animals with a coelom can be divided into
1- acoelomate = no cavity, coelom, in mesoderm
2- pseudocoelomate = doesnt have true coelom
3- coelom = has true coelom
what is the purpose or need for a blood system
- occurs mainly in triploblastic animals
- due to mesodermal organds sep digestive tract from body wall diffusion cant occur
- a need for transp system arises
- blood system transp O2, CO2, digested nutrients
phyla that are acoelomate and dont have a blood system
1- porifera = cellular tissue lvl, so no mesoderm for coelom, no coelom means no blood system
2- cnidaria = diploblastic so no mesoderm which means no coelom, no coelom means no blood system
3- plathelminthesis = a category, even tho it has 3 layers (mesoderm) it has no coelom and thus no blood system
phyla that are coelomate and their type of blood system
1- annelida = closed blood system
2- arthropoda =open blood system
3- chordata = closed blood system
what is animals with only one gut opening called
blind ending gut
what are the chrcts of blind ending gut (5)
1- food consumed thro opening and food excreted thro the same opening
2- only one opening for both the mouth and anus
3- limits amount of food that can be consumed
4- digestion is a discontinuous process: new food can only be taken in when all food already ingested has digested and egested
5-digested and undigested material mix
what is animals with 2 gut openings called
through gut
what are the chrts of through gut (4)
1- 2 openings mouth and anus
2- incoming food doesnt mix with outgoing undigested food
3- digestions is a continuous process
4- diff regions of digestive tract can become specialised to improve efficiency
