Lecture 7: Animal Phyla Part `1 Flashcards
Animals are heterotrophs meaning?
they need to ingest their food unlike plants which are autotrophs
Some other animal facts?
- heterotrophs
- multicellular
- no cell wall
- most animal reproduce sexually
What is the origin of animals?
the hypothesis is that they evolved from a group of colonial protists called choanoflagellates
evidence is: colar cells preset in animal phyla but not in plants, dna is highly similar
Animals share body plan characteristics that can be compared among groups, what are the 6 characteristics?
symmetry, tissues, body cavities, digestive cavities, development, skeleton
What are the 3 types of symmetry?
1) asymmetry: not symmetrical like sponges
2) radial symmetry: does not have a right or left side like sea stars
3) bilateral symmetry: have right and left sides like humans
What are tissues?
group of similar cells carrying out a main function: embryonic germ layers form as the embryo develops, become tissue and organs
Ectoderm?
outer layer; forms outer covering and CNS
Mesoderm?
middle layer; forms all other tissues/organs
Endoderm?
inner layer; forms digestive tract/ cavity lining, organs like liver and lungs in vertebrates
Whats a diploblastic animal?
has 2 layers including ectoderm and endoderm
Whats a triploblastic animal?
has 3 layers including ectoderm, mesoderm, and endoderm; all bilateral animals triploblastic
Body cavities?
fluid filled spaces between tissue layers during the early development of organisms: function in support, nutrient transport, and waste removal
Whats coelom?
a fluid filled cavity surrounded by mesoderm:
- cushions and holds organs in place
Acoelomate?
have no coelom to help the organism develop more complex internal organs: aka no body cavity surrounded by mesoderm
Pseudocoelomate?
have a fake coelom; only partially surrounded by mesoderm therefore organs are held loosely in place
Coelomates?
have a true coelom: complex organ systems can develop within their coelom: better reproduction, mobility,and communication
Digestive cavities
- 1 way flow
- gastrovascular cavity: gut with one opening; food is ingested and waste is secreted from one opening ex: jellyfish
- alimentary cavity: gut with 2 openings: ex: dog
Development protostome vs deuterostome
protosome: the mouth develops from the blastopore
deuterosome: the anus develops from the blastopore
during embryonic development of animals with bilateral symmetry, the first opening produced is called the?
blastopore
Skeleton?
a skeleton system functions for support, to protect internal organs, and allow for the movement
what are the 3 types of skeleton designs?
endoskeleton, exoskeleton, and hydrostatic skeleton
What is an endoskeleton?
skeleton that consists of hard mineralized structures located within the soft tissues of organisms; vertebrates
What is an exoskeleton?
external skeleton that consists of hard encasement on surface of organism; crab or beetle
What is a hydrostatic skeleton?
flexible skeleton supported by fluid pressure; earthworms, starfish
Porifera/sponges?
suspension feeders- eat what pass through their cavity & live in aquatic habitats
1) asymmetric
2) no tissue or organ
3) no body cavity
4) no digestive cavity
5) n/a
6) hard spicules or soft spongin/endoskeleton
Cnidaria?
examples: jellyfish, corals, hydra, anemones
live in aquatic habitats
1) radial symmetry
2) diploblastic
3) no body cavity
4) gastrovascular cavity
5) n/a
6) hydrostatic skeleton
Platyhelminthes?
flatworms, tapeworm, planaeia
some are free living aquatic and some are parasitic
1) bilateral symmetry
2) triploblastic
3) compact coelom
4) gastrovascular cavity
5) protosome development
6) hydrostatic skeleton
