16 Flashcards
Traits that unifies animals?
•collagen to make their tissues (in their extracellular matrix)
Collagen does what?
Keeps your cells together
Animals are sister to?
Choanoflagellates
Why aren’t choanoflagellates considered animals?
They dont have collagen
Big evolution of Bilaterian?
The evolution of symmetry
!!!Embryonic development in animals?
Cleavage: Zygote to two cells and divide into a blastula (hollow ball of cells). Gastrulation occurs and an opening occurs in the blastula called blastopore (early gastrula layer) by the inner membrane folding inside and creating two layers, endoderm and ectoderm. It either becomes the mouth or anus. The blastula can either become diploblastic or triloblastic.
Sponges are animals that lack?
True tissues, muscles, neurons, symmetry
What gives sponges structural support?
Mineral spicules
Ctenophores main traits?
Synapomorphy: 8 combs of cilia
•Radial symmetry
•Diploblastic
•Marine predators
•Flow through gut
Cnidaria traits?
•Aquatic, almost all marine
•Polyp and/or Medusa forms
•Radial symmetry
•Diploblastic
•No flow through gut
•Synapomorphy: cnidocytes
Cnidocytes?
Stinging cells
99% of animals are?
Bilateria
!!! All traits of bilaterians?
Taxa of lophotrochozoans? 3•
•Flatworms
•Mollusks
•Annelids
What unifies lophotrochozoans?
DNA evidence
Two big groups in Ecdysozoans?
Nematodes, arthropods
Traits that all organisms share in ecdysozoans?
She’d their exoskeleton
Do nematodes have appendages?
No
Why are Nematodes within ecdysozoans?
They shed their cuticle. They have to stay moist.
Anthropoids have a waxy exoskeleton which can suffocate them. How do they solve that?
They perform gas exchange through spiracles in their exoskeleton.
Diploblastic animals?
two cell layers: endoderm, ectoderm
Triploblastic animals?
Endoderm, mesoderm, ectoderm
Which groups are diploblastic?
Ctenophores, cnidarians
Which groups are triploblastic?
Bilaterians
Two types of symmetry?
*Radial
*Bilateral
Radial symmetry?
symmetric as a circle
Groups that are radially symmetrical?
Diploblastic animals
Groups that are bilateral symmetrical?
Triploblastic animals, mostly, as echinoderms are radially symmetric as adults
What does ectoderm, mesoderm, and endoderm usually correspond to? 3*
Ectoderm: skin, nerves
Mesoderm: muscles
Endoderm: gut
In protostomes, blastopore becomes?
The mouth
In deuterostomes, the blastopore becomes?
The anus
Three types of body cavities among triploblastic animals?
*Acoelomate: filled with tissue
* pseudocoelomate: internal organs are lined with mesoderm but it does not surround
*coelomate: both the outer wall and all the internal organs are lined with mesoderm and surrounded
choanoflagellates?
Aquatic, filter feed on bacteria, and its synapomorphy is collar of sticky tentacles to capture and eat bacteria. They have a simple posterior flagellum. Unicellular
Sponges?
Aquatic, almost all marine, filter feeding, mostly sessile, and multicellular, except Eumetazoa. They attach to the ocean floor and there is water flow from the button to the top which they absorb nutrients from.
Their synapomorphies: mineral spicules to help support the body of the sponge.
How do sponges reproduce?
Asexually via budding or fragmentation, but can also sexually through broadcast spawning.
Ctenophores?
All marine, predators, radial symmetry, and flow through gut (nutrients enter through one side and exit through another).
Synapomorphy: 8 combs
Cnidaria?
Jellyfish, hydras, anemones, and corals. All aquatic, almost all marine, polyp or medusa. Radially symmetry, no flow through gut.
Synapomorphy: cnidocytes (explosive stinging/adhesive cells)
No flow through gut with one opening in their digestive tract.
Hydras?
Cnidarians and only have a polyp stage
Amnemones and corals?
both polyp and larval stage
Synapomorphies of Bilateral?
*Bilaterally symmetric
*Triploblastic
Bilateria is sister to?
Cnidarians
Bilateria is separated by?
Protostomes and Deuterostomes
Lophotrochozoas?
apart of protostomes. The trochophore larva have a band of cilia around its middle that it uses to swim and bring food particles to its mouth. It has been lost in some groups.
Synapomorphy: DNA evidence
Flatworms consist of?
Flatworms, tapeworms, and flukes. They are acoelomate. They have some cephalization (concentration of sense organs and neurons), no circulatory system, and
Lophotrochozoans include what groups?
flatworms, mollusks, annelids
Characteristics of flatworms?
*Acoelomate
*Blind-gut
*Parasitic taxa
*No circulatory system
*Free-living taxa
*Cephalized with ventral nerves
flatworms do not have?
A circulatory system (easily gas exchange because of gas exchange) and some have lost their digestive tract since they only consume digested food from hosts.
annelids?
Segmentation, closed circulatory system, coelomate, chitinous setae. fragmentation allows differentiation of function. the setae aid in locomotion by sticking into the substrate. They are coelomate: internal coelom with mesoderm lining the coelom and covering the internal organs. They have some cephalization
Annelids can be where?
Marine
Freshwater
Terrestrial
Annelids have?
Cephalized: anterior brain and ventral nerve chord
Mollusk?
Almost all aquatic, some terrestrial detritivores, filter feeds, and predators. They have open circulatory system and more cephalization.
Synapomophories: Muscular foot, visceral mass, mantle. They are coelomates
They include octopuses
Visceral mass?
centralized mass of centralized organs covered by a fold of tissue called the mantle. most species undergone tortion so the anus protrudes from the same hole in the shell from the head and foot.
Mantles can lead to?
Shells
Do sponges have tissue layers?
No, they do not
Which animals can you break apart and yet still function and regrow?
Sponges because they do not have tissue layers
Eumetazoans?
Animals with true tissues, gastrulation, symmetrical body plan, and internal gastrovascular system. Sponges do not have any of these.
Polyp stage?
A stage that attaches to the sea flow with tentacles pointing up
Corals have a symbiosis relationship with?
Polyp and dinoflagellates
Hox Genes?
Sets of genes that code for transcription factors that determines major factors of body plan development.
Synapomorphy that primarily combined Cnidarian and bilaterians?
Hox Genes
Bilateria evolved around?
Right before the Cambrian explosion 540 Mya.
