Pattern of blastopore formation
Radial cleavage pattern for cell division
Number of primary germ layers
The first cleavage divisions of the fertilized embryo produce identical daughter cells, and any single cell, if separated can develop into a complete organism.
The coelom is normally produced by an invagination of the archenteron.
Protostomes are animals in which the mouth develops from the blastopore. The anus or anal pore of protostomes develops from the second opening. Deuterostomes are animals in which the anus develops from the blastopore and the mouth develops secondarily later in their development.
Protostomes are animals in which the anus develops from the blastopore. The mouth of protostomes develops from the second opening. Deuterostomes are animals in which the anus develops from the blastopore and the mouth develops secondarily later in their development.
Protostomes are animals in which the mouth develops from the blastopore. The anus or anal pore of protostomes develops from the second opening. Deuterostomes are animals in which the mouth develops from the blastopore and the anus develops secondarily later in their development. Protostomes are animals in which the mouth develops from the blastopore. The anus or anal pore of protostomes develops from the second opening. Deuterostomes are animals in which the mouth develops from the blastopore and the anus develops secondarily later in their development.
Protostomes are animals in which the mouth or anus develops from the blastopore, depending on the species. Deuterostomes are animals in which the mouth and anus develops from the blastopore, depending on the species.
Deuterostomes demonstrate radial cleavage in their embryonic development.
Deuterostomes display indeterminate development.
A deuterostome's coelom is produced by invagination of the archenteron.
Examples of deuterostomes are echinoderms and chordates.
Includes most bilaterians, including flatworms, nematodes, mollusks, annelids and arthropods.
Embryonic cells have a predetermined fate
Bilateral symmetry cannot develop
Early embryonic cells, if separated from the embryo, can develop into complete organisms.
Embryonic cells show spiral cleavage.
The blastopore develops into the mouth.
Conferring anterior and posterior areas to the body.
Allowing for greater efficiency in movement.
Creating a body design of two mirror images.
Allowing for efficiency in seeking food and mates.
They constitute millions of species.
They are very diverse in form.
They were some of the first organisms on the earth.
They show great mobility.
They are found in every conceivable habitat.
Their cells lack rigid cell walls and are flexible.
They can move more rapidly and in more complex ways than members in other eukaryotic kingdoms.
They develop from a zygote in a characteristic embryonic development.
They show great diversity in size, form and structure.
They are homotrophic.
Definite shape and symmetry.
Tissues organized into organs and organ systems.
Distinct embryonic layers which differentiate into adult tissues.
The Hox genes.
Having cells organized into tissue layers.
Diploblastic- ectoderm and mesoderm
Triploblastic- ectoderm, mesoderm, and endoderm
Parazoa- lacks symmetry; no tissues
Eumetazoa- definite symmetry; tissues organized
Chordate- animal with notochord
Cnidaria, Mollusca, Platyhelminthes
Porifera, Arthropoda, Nematoda
Nematoday, Chordata, Cnidaria
Mollusca, Arthropoda, Chordata
Platyhelminthes, Nematoda, Arthropoda
Acoelomates have no body cavity.
Coelomates have a body cavity lined with mesodermal cells.
Coelomates have a fluid filled cavity that develops entirely within the mesoderm.
Pseudocoelomates have a body cavity that is located between the ectoderm and the endoderm.
Are bilateral symmetrical
Evolved from protostomes.
Are animals in which the blastopore develops into the mouth.
Are animals in which any cell can develop into a complete organism.
Annelida, Mollusca, Arthropoda
Echinodermata, Platyhelminthes, Cnidaria
Mollusca, Chordata, Annelida
Arthropoda, Chordata, Porifera
Arthropoda, Annelida, Chordata
Circulatory system present
The common ancestor was a protist.
The common ancestor was a hollow spherical colony of flagellated cells.
Cells within sponges resemble choanoflagellate protists.
Sponges evolved independently from eumetazoans.
Metazoans represent a monophyletic group.
No true tissues
Often bioluminescent marine animals
Open or closed circulatory system
Blastopore opens into the archenteron
Three primary tissue layers
Body parts arranged around a central axis
Number of embryonic tissue layers
Fate of the blastopore
Cells organized into tissues
Movement associated with muscle tissue and nervous tissue
Cells without walls
Clades consist of monophyletic taxa sharing the same gene sequences.
Different molecules sometimes support different taxonomic relationships.
Molecular data suggests that arthropods and annelids are part of the same clade.
Molecular data suggests that a new group of "molting" animals, the Ecdysozoa, is monophyletic.
Combining data from many different molecules gives the best picture of phylogenetic relationships.
Segmentation can produce redundant systems.
Segmentation can enhance locomotion
Only three phyla show true segmentation.
The evolution of segmentation is highly convergent.
Although fusion of segments is common, a study of embryology makes segmentation evident.
Most taxonomists agree that the origin of the metazoans is polyphyletic.
The multinucleate hypothesis states that metazoans arose from multinuclear protists.
The colonial flagellate hypothesis states that metazoans arose from choanoflagellate-like protists.
The polyphyletic origin hypothesis states that the sponges evolved independently from the eumetazoans.
Molecular data shows that metazoans are more closely related to flagellates than to ciliates.
Platyhelminthes and Nematoda.
Nematoda and Arthropoda.
Annelida and Mollusca.
Mollusca and Arthropoda.
Platyhelminthes and Arthropoda.
Stomachs of vertebrates.
Lungs of vertebrates.
Livers of vertebrates.
Intestines of vertebrates.
Hearts of vertebrates.
Radial to bilateral symmetry
No body cavity to body cavity
Unsegmented to segmented bodies
Protostome to deuterostome development
Eating by flow of water through canals and pores.
Free-swimming larvae; sessile adults.
Lack of specialized tissues and organs.
Lack of symmetry (may be radial in small species).
Head or appendages, mouth or anus.
A digestive cavity lined with enzyme-secreting cells.
Mesophyl, a protein-rich matrix.
A somewhat contractile outer epithelium.
Specialized collar cells or choanocytes.
Spicules or a spongin skeleton, or both.
They are widespread and abundant especially in shallow, warm-temperature or subtropical waters.
They are basically gelatinous in composition.
Their bodies are made up of distinct organs.
They exist either as polyps or medusae.
They contain specialized cells called "cnidocytes" within which nematocysts are found.
Some may have hard calcium carbonate exoskeletons.
The coral animals are always found in nutrient-rich waters.
Some participate in the formation of shallow-water limestone ridges.
Many harbor symbiotic algae.
They are a class of cnidarians.
Solid bodies with an inner digestive cavity.
Flat ribbon-shaped bodies with dorso-ventral parts and anterior head.
All are free-living.
Possess an excretory system.
Contain an excretory system lined with a network of fine tubules running through the body
Contain an incomplete gut with only one opening
Cilia line the hollow centers of bulb-like flame cells
Lack circulatory systems for transport of oxygen and food
Most are hermaphroditic
Carp or goldfish.
Occur as a juvenile in the intermuscular tissue of cattle
Found as an adult in the intestines of human beings
Able to produce embryos, which may be viable for up to five months
Able to reach adult length of up to 10 meters
More than 10% of the cattle are infected in the United States
They possess an internal body cavity called a pseudocoel.
They contain a bony skeleton.
They possess a complete, one-way digestive tract.
The pseudocoel permits resistance to muscle contraction.
They lack a defined circulatory system.
Corona is food gathering organ
Live on mouthparts of lobsters
Complete gut with mouth and anus
Most occur in fresh water