Bio Exam 4 Class 2 (Protostomes) Flashcards
the coelom in protostoes is formed with a
hollowed mesoderm
the celom in deuterostomesis forned with a
pinched off mesoderm
what is a protostome?
-bilaterian
-triploblastic
-the mouth forms first
-monophyletic group
protostomes include phyla:
arthropds, mollusks, and annelids
(ex. insects clams worms)
most animal species are
protostomes
protostomes are found virtually in
every habitat and ecosystem
protostomes transitioned from
water to land
protostomes evolved adaptations to:
-exchange gases
- avoid dessication
- support their body weight
how did protostomes evolve to be more efficient in gas exchange
- body with high surface area to volume ratio
how did protostomes evolve to decrease water loss?
-eggs with thick membrane or shell
- gills/ respiratory organs inside the body
- cuticles on body with spiracles
spiracles are similar to the - in plants?
stomata
how did protostomes evolve to provide support and protection?
-exoskeleton
- shells
the waxy cuticle in protostomes
kept moisture in the protostome
internalized gills and spiracles allowed protostomes
to breathe on land with the cuticle which helped them keep from drying out
many protostomes have a
hemocoel
what is a hemocoel:
-reduced coelom that is not lined by the mesoderm
bathes the organs in body fluid in an open circulatory system
what is the differnce between an oepn circulatory system and close circulatory system?
open: bathes all of the cells
closed: carries to each cell individually
why are protostomes small?
there is an issue with their surface area to volume ratio
- the larger you get the less able you are gong to be to have an open circulatory system
- the fluid simply would not be able to reach the entire system of the organism
*spiracle and gillsar enot as efficient with pupu=ing oxygen
what are the two lineages of protostomes:
-lophotrochoza
-edcystozoa
lophotrochozoans include:
-rotifer
-flat worms
-annelids (segmented worms)
- mollusks
what are the 3 synapomorphies of lophotrochozoans?
- the lophophore: th emouth structure with tentacles
- the trochophore: cilia that allow larval organisms to capture food
- the spiral cleavage:everything else is radial
what are lophophores?
th emouth structure with tentacles
what is the trochophore?
cilia that allow larval organisms to capture food
what are the 3 specialized traits of mollusks?
- the foot
- the visceral mass-region containing internal organs, external gill, and radula
-with the hemocoel
-the mantle- secretes s calcium shell, and can be used to propel themselves
what does the foot do?
allows for movement
- in quid and octopi the foot is modified into tentacles
what is the visceral mass?
region containing internal organs, external gill, and radula
what are rotifers?
- live in aquatic habitat
- feed by predatory suspension
-movement by beating cilia - mostly sexual
what are flatworms?
- aquatic or internal animal
- predatory or parasitic feeding
- hydrostatic skeleton or swimming or swimming
- asexual or sexual
what are annelida?
- aquatic or internal
-predators, detritivores, or parasites - hydrostatic skeleton or swimming or swimming
- asexual or sexual
what are mollusca?
snails, clams, mussels,
- aquatic
-predatory or
what are ecdysozoans phyla?
- nematodes
- tardigrada
-onychophora
-arthorpods
what is the one synapomorphy of ecdysozoans?
they molt their exoskeleton
what are 3 specializations within arthropods?
- segmented body
-jointed appendages
-chitin exoskeleton
the segments of the arthropods are:
tagmata that are seperated into the head, thorax, and abdomen
arthrobod bodies exhibit
serial homologies, aka all of their segments are relatively homologous but can be speialized for different functions
another specialized form of some arthropods is
wings
tardigrades are
extremophiles
