Midterm 1 Flashcards
(112 cards)
Fossils
remains of older life forms, vestiges of once living organism
Fossilization
process through which a living organism is turned into a fossil.
Bryophytes
simplest land plants, lack woody tissue and reproduce through spores
tracheophytes
higher plants with woody tissue, this is further separated into seed and seedless plants.
Protozoans (animal-like protistans)
diverse single-celled eukaryotes
Characteristics of foraminifera
- Animal like protistans
- solitary organisms
- cytoplasm protected with tests
- Tests have one (unilocular) or more (multilocular) chambers
characteristics of radiolarians
- animal-like protistans
- solitary
- mineralized structure (skeleton) protects the cytoplasm
- skeletal structure that provides highest quality fossil record, most elaborate skeletal systems among fossils
characteristics of ciliophorans
- Animal-like protistans
- single-celled
- solitary
- 2+ nuclei in the cytoplasm
- protect their body with a lorica
Choanoflagellates
- Animal-like protistans
- solitary or colonial
- poor fossil record
sponges
- The simplest multicellular animals on Earth
- Evolve tissue grades so they don’t have organs
- cylindrical shape with large opening at the top (osculum) and small pores that penetrate through the lateral walls
Feeding process of sponges
Structure of the body is made for filter feeding. The flagella create a current that enters the body through the pores and is expelled through the osculum
Poriferans
they distinct phylum that includes sponges
Sponges/poriferans internal skeletal composition
skeleton has small-sized spicules, they can be calcareous.
4 subclasses of phylum
Calcarea- calcareous skelton
Demospongea- skeleton consists of siliceous spicules
Hexactinellida- skeleton consists of siliceous spicules w/ 3 axes
Sclerospongia- calcareous skeleton with different skeleton architecture than calcarea
Cnidarians
characterisized by nematocyts; cells that release a deadly poison that can paralyze the prey
- they can either be sedentary generation or free-swimming generation
Lophophorates
characterized by a fan shaped organ that filter-feeding, known as lophophore. Two phyla: Bryozoa and Brachipoda
Bryozoa vs. Brachipoda -
Bryozoans- colonial
Brachiopods- most frequent in the fossil record, they protect their soft bodies with two valves. Brachiopods are subdivided into inarticulata which lack a hinge and articulata have a hinge with well-developed teeth
Molluscs
Organisms of the phylum Mollusca that are soft-bodied animals, often protected by a shell of CaCO3. they are one of the most important reef builders throughout the phanerozoic period.
Aplacophora
molluscs without hard body parts/no shell, they do not appear in the fossil record
Polyplacophoro
molluscus that have soft body parts protected by a number of plates that overlap each other, they appear in the Devonian period
monoplacophora
protect the soft body parts with one calcitic piece/shell, very similar to gastropods
gastropods
Molluscus that evolved in the Cambrian and are among the most diverse and abundant groups of organisms, the are adapted to aquatic areas and soft body parts are protected by twisted shell
Cephalopods
molluscs with tentacles around the mouth (octopi and squid) shell is external in nautiloids (octopi and squid) and internal in some squid.
Scaphopods
class of molluscs that are tapered and elongated shell that protects the soft body, tentacles around the mouth that help catch prey.