Theme 2 Phylum Clasification Flashcards
How are organisms classified (by what characteristics)
Genetics
Morphology
Physiology
Behaviour
Heritable traits
What is a clade
A monophyletic group made of a taxa with a unique common ancestor
They are share synapomorphies
What is a synapomorphy
Shared derived characters
What is a taxa
A level in a systematic heirachy
What is the order of linens classification
Kingdom
Phylum
Class
Order
Family
Genus
Species
What did the ancestral colonial protist in animal phylogeny split into
Basal phyla and bilaterians
What organisms are included in the basal phyla
Ctenophores
Sponges
Placozoans
Cnidarians
What is included in the bilaterians group
Acoela, protostomes, deuterostomes
What is included in deuterostomes
Ambulacra (sea urchins, sea stars)
Chordates
What is included in protosomes
Lophotrochozoans
Ecdysozoans
What does bilaterians mean
Bilateral symmetry
What do ctenophores, placozoans and cnidarian have in common
They have radial symmetry, and are diploblastic (have 2 germ layers ecto and endoderm)
What is the blastopore in protostomes
The mouth
What is the blastopore in deuterostomes
Anus
What are protostomes and deuterostomes (in terms of blastics)
Triploblastic (three germ layers)
Endo meso and ectoderm
Organisms that a diploblastics have what king of symmetry
Radial
What is radial symmetry
They can be any which way and stil look the same
What type of symmetry do triploblastic things have
Bilateral ( only symmetric if cut through middle)
What is cephalization
One end of the organism is emphasized (head)
What are hox genes
The central programming, they call specific genes (turn on) for specific traits and that contributes to creating the body plan
What are hox mutants
When the hox genes turn the wrong gene on in the wrong spot, leading to abnormal body plan
Fly has a leg where antennae is
What is the coelem
The body cavity, empty space between the organs
Do acoela have coeloms
No the are acoelamate
What is psudocoelomate
What organisms are like this
The Coelom (cavity enclosing the gut) if surrounded my mesoderm on the outer side
Or
Endoderm and Coelom touch each other
Most protostomes
What is coelomate
The coelom is not tounching endoderm,
Mesodermal surrounds it on both sides
How do protostomes develop after becoming a zygote
They are a four cell embryo then become eight cell through spiral cleavage (top four cell are not lined up with bottom four)
How do deuterostomes develop after becoming a zygote
First four cell embryo then become eight cell through radial cleavage (top and bottom are lined up)
How are the mesoderm and coelom formed in protostomes
Once the blastopore is made, the mesoderm encases the coelom on both sides of the blastopore. The coelom is now called schizocoelom
How are the mesoderm and coelom formed in deuterostomes
Once the blastopore is made, the mesoderm cells form two points (cat ears) on the top of the blastopore. The coelom is in the spaces of those cat ears
Called enterocoelom
What is the archenteron
The endoderm space in the blastopore
How do the moth and anus form in deuterostomes and protostomes
In protostomes, the blastopore turns into The mouth then the anus formed later
In deuterostomes The anus forms first and the mouth forms after.
They end up with the shape shape, just inverted
What are the diff between protostomes and deuterostomes
Protostomes:
determinate cleavage (if you took a cell from one part of its embryo it wouldn’t form a new embryo)
Ventral nerve cord the surround digestive tracts anteriorly
Deuterostomes:
Indeterminate cleavage
Dorsal nerve cord, does not surround digestive tract
