ACTIVITY 1 Flashcards
LUCA
last universal common ancestor
was believed to be alive around 3.5 billion years ago.
Scientists believe all life as we know it has evolved from a common ancestor
LUCA
We have discovered just around 1.3 million species, but scientists predict that there are several million more out there that we haven’t discovered yet.
true
The system most used is based on the characteristics of living things and this
taxonomy was first formalized by who in the eighteenth century.
The system involves sorting living things into groups and breaking those groups into multiple subgroups.
Carl von Linné (Carolus Linnaeus)
The largest groups of life are domains, of which there are three:
Bacteria, Archaea, and
Eukarya
are all around us but are difficult to see without a microscope.
mostly free-living organisms often consisting of one biological cell.
Bacteria
are unicellular organisms that are the only life able to survive in the most extreme conditions.
Archaea
have a cellular nucleus in common
and are what we typically think of as “life”.
Eukarya
six kingdoms
Animals, Plants, Fungi, Protists, Bacteria, and Archaea
are considered both domains and kingdoms.
Bacteria and Archaea
Eukarya domain contains the other kingdoms:
Eukarya domain contains the other kingdoms:
is a group of organisms that can reproduce and make fertile
offspring
species
taxa
Domain
Kingdom
Phylum
Class
Order
Genus
Species
refers to various names according to a specific field of study
Scientific nomenclature
is the clade of animals once thought to be characterized by the formation of the organism’s mouth before its anus during embryonic development.
Protostomia
typically characterized by their anus forming before the mouth during embryonic development.
Deuterostome
lacks true tissues and organs but consists specialized cells to perform different functions
Without true Tissue
Asymmetrical
No germ layers
No body cavity
Phylum Porifera
possess specialized cells called cnidocytes, which contain stinging structures call nematocysts for defense mechanism
With true Tissue
Radial
2 germ layers
No body cavity
Protostome
Phylum Cnidaria
flattened body shape with bilateral symmetry
With true Tissue
Bilateral
3 germ layers
No body cavity
Protostome
Phylum Platyhelminthes
cylindrical, unsegmented body
With true Tissue
Bilateral
3 germ layers
with body cavity
pseudocoelomate
Protostome
Phylum Nematoda
closed circulatory system
Bilateral
3 germ layers
with body cavity
pseudocoelomate
Protostome
Phylum Annelida
have highly specialized nervous system and exhibit a wide range of adaptations for different environments
Bilateral
3 germ layers
with body cavity
pseudocoelomate
Protostome
Phylum Arthropoda
exhibit a unique water vascular system used for movement, feeding, and gas exchange.
Radial
3 germ layers
with body cavity
Deuterostome
Protostome
Phylum Echinodermata
presence of notochord which is a dorsal hollow nerve cord.
With true Tissue
Radial
3 germ layers
with body cavity
coelomate
Protostome
Phylum Chordata
have muscular foot for movement
With true Tissue
Bilateral
3 germ layers
with body cavity
coelomate
Protostome
Phylum Mollusca
organisms that have false body cavities. They have a fluid-filled body cavity separating the gut of the organism from the body wall but it is not lined by mesoderm
pseudocoelomate
have a body cavity called a coelom with a complete lining called peritoneum derived from mesoderm
coelomate
