Animal Diversity Flashcards
are groups of similar cells that act as a
functional unit
tissues
after a sperm fertilizes an egg, the zygote undergoes rapid cell division called
cleavage
cleavage leads to formation of a multicellular, hollow
blastula
The blastula undergoes _____, forming a ____ with different layers of embryonic tissues
gastrulation, gastrula
A ____ is sexually immature and morphologically distinct from the adult; it eventually undergoes ______ to become a juvenile
larva, metamorphosis
-Early macroscopic members of the animal fossil record include the Ediacaran biota, which dates back to about 560 million years ago
-Named after a region in Australia, where such fossils that were first found.
-Molluscs, sponges, cnidarians
Neoproterozoic Era (1 Billion–542 Million Years Ago)
-The Cambrian explosion (535 to 525 million years ago) marks the earliest fossil appearance of many major groups of living animals
-Most of the fossils from the Cambrian explosion are of bilaterians, organisms that have the following traits: Bilaterally symmetric form, Complete digestive tract, One-way digestive system
Paleozoic Era (542–251 Million Years Ago)
-Coral reefs emerged, becoming important marine ecological niches for other organisms
-Dinosaurs were the dominant terrestrial vertebrates
-Flowering plants and insects dramatically
diversified
Mesozoic Era (251–65.5 Million Years Ago)
-The beginning of this era followed mass extinctions of both terrestrial and marine animals
-Mammals increased in size and exploited vacated ecological niches
-The global climate cooled
Cenozoic Era (65.5 Million Years Ago to the Present)
a set of morphological and developmental traits integrated into a functional whole
body plan
no front and back, or left to right
radial symmetry
two sided symmetry
bilateral symmetry
collections of specialized cells isolated from other tissues by a membranous layers
tissues
the germ layer covering the embryo’s surface
ectoderm
is the innermost germ layer and lines the
developing digestive tube, called the archenteron
endoderm
animals have ectoderm and endoderm
diploblastic
______ animals also have an intervening ______ layer; these include all bilaterians
triploblastic, mesoderm
true body cavity is called a ______ and is derived from mesoderm
coelom
are animals that possess a true coelom
coelomates
a body cavity derived from the mesoderm and endoderm
pseudocoelom
Triploblastic animals that possess a pseudocoelom
pseudocoelomates
Triploblastic animals that lack a body cavity are
acoelomates
In protostome development, cleavage is ____ and ______
spiral, determinate
In deuterostome development, cleavage is _______ and _______
radial, indeterminate
In deuterostome development, the mesoderm buds from the wall of the ______ to form the coelom
archenteron
The _______ forms during gastrulation and connects the archenteron to the exterior of the gastrula
blastopore
is a clade of invertebrates that shed their
exoskeletons through a process called ecdysis
ecdysozoa
includes hemichordates (acorn worms), echinoderms (sea stars and relatives), and chordates
deuterostoma
is another clade of bilaterian invertebrates
lophotrochozoa
Some lophotrochozoans have a feeding structure called a
lophophore
Others go through a distinct developmental stage called the
trochophore larva
