Animalia Flashcards
What is an animal?
Consumes organic matter (heterotrophic) Consumes oxygen Able to move Reproduces sexually or had an ancestor that reproduced sexually Developed from a blastula (there are exceptions to all of these)
What are choanflagellates?
Unicellular eukaryotes (not animals)
Can be free living or colonial
Have a funnel shaped collar
Do both sexual and asexual reproduction
What is the ‘ur-metazoan’?
The hypothetical last common ancestor of all animals
Describe the ‘ur-metazoan’
First eukaryotic multicellular animal Flagellate Marine animal Diploblastic No symmetry
What are basal metazoans?
Non-bilateral animals
Asymmetrical or radially symmetrical
Have two cell layers
Have no organs but some differentiated tissues
What is bilateral symmetry?
The right and left sides of an organism are divided by a single plane through the midline and are mirror images of each other.
What are the types of cell layers?
Three cell layers
Ectoderm (epidermis and nerves)
Endodem (digestive tract)
Mesoderm (muscle and connective tissue)
What are the two divisions of bilateria?
Protostomia (mouth first)
Deuterstomia (anus first)
What are the two divisions of protostomia?
Ecdysozoa- arthropods/nematodes
Spiralia- rotifers/flatworms/molluscs/annelids
Describe ecdysozoans
Grow by ecdysis Lack locomotory cilia Produce ameboid sperm Have 'teeth' in the foregut Have a ring of spines around the mouth
Describe spiralians
Named after spiral cleavage of embryo
Lack ecdysozoan traits
What are the two divisions of spiralia?
Lophotrochozoa
Gnathifera
Describe lophotrochozoans
Have a ciliated crown of tentacles surrounding a mouth
Have trochopore larvae that have bands of cilia used in locomotion and feeding
What are porifera?
Sponges
Describe porifera
Diploblastic
No tissues or organs
No symmetry
How do porifera carry out respiration and feeding?
Have an aquifeous system
Water pulled in through ostia
Water driven across choanoderm by the beating of choanocyte flagellate
Choanacytes pump large volumes of water through body at low pressure to establish a current
Water flows close to cells for food/gas exchange
Waste excreted via osculum
How do porifera sexually reproduce?
They are hermaphrodites thus produce eggs and sperm at different times by choanocytes which are then released via the aquiferous system.
How do porifera asexually reproduce?
Fragmentation
Budding
Asexual larvae
What are the three sponge classes?
Calcarea
Hexactinellida
Demospongia
Describe the spicules of calcarea sponges
Have rayed spicules (1,3,4) made of CaCO3
Describe the spicules of hexactinellida sponges
Six rayed and made of silicon
Describe the spicules of demospongia sponges
Six rayed but not made of silicon
Describe placozoa
Close to the ‘ur-metazoan’
Simplest animal structure
Diploblastic
Reproduce by asexual budding
What are ‘coelenterates’?
Former term for cnidaria and ctenophora but is now a paraphyletic group.
Describe Ctenophora
Radial symmetrical Diploblastic Have sticky colloblast cells Bioluminescent Swim using cilia
Describe Cnidaria
Symbiotic (live in close relation with other organisms) Bioluminescent Diploblastic No nervous system Very diverse group Have cnidae
What are the three types of cnidae?
Penetrant (pierces)
Glutinant (sticks)
Volvent (coils)
What are the different generation types?
Polyploid phase - all classes,sessile,asexual
Medusoid phase- medusozoa, free, sexual
