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42 Cards in this Set

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What are the four features that define an animal's body plan?
1) the number of tissue types in embryos 2) the type of body symmetry 3) the presence or absence of a fluid-filled cavity 4) the way in which the earliest events of embryo development proceed
Animals whose embyros have two tissues or germ layers: ectoderm and endoderm
Animals whose embryos have three tissues or germ layers: ectoderm, endoderm and mesoderm
What is cephalization?
the evolution of a head, or anterior region, where structures for feeding, sensing the environment and processing information are concentrated (allowed by bilateral symmetry)
What is an internal fluid-filled body cavity that creates a medium for circulation and space for internal organs called?
what is a 'false coelom' that is not lined with mesoderm on both sides?
what is a fluid-filled chamber that allows an animal to move even without fins or limbs?
hydrostatic skeleton
_____ have no body cavity
______ have a body cavity partially lined with mesoderm
______ have a body cavity completely lined with mesoderm
The group Bilatera can be divided into which groups?
Protostomes and Deuterostomes
Arthropods, mollusks and segmented worms are all ____
vertebrates and echinoderms are both ______
what events in early development differ in protostomes and deuterostomes?
cleavage, gastrulation and coelom formation
What is different about the cleavage formation between protostomes and deuterostomes?
Protostomes have spiral cleavage- mitiotic spindles of dividing cells orient at an angle to the main axis of the cells resulting in a helical arrangement
Deuterostomes have radial cleavage- the spindles orient parallel or perpendicular to the main axes of cells, resulting in a stacked arrangement
What is different about the gastrulation process between protostomes and deuterostomes?
Protostomes- blastopore becomes the mouth
Deuterostomes- blastopore ecomes the anus
What is gastrulation?
the ball of cells formed by cleavage invaginates to form gut and embryonic tissue layers
What is cleavage?
a rapid series of mitotic divisions that occurs in the absence of growth
What is different about the coelom formation between protostomes and deuterostomes?
Protostomes- the block of solid mesoderm splits open to form coelom
Deuterostomes- messoderm pockets pinch off the gut to form coelom
Describe the tube-within-a-tube design
the outer tube forms the body wall and the inner tube forms the gut; most organs are located between the two tubes; the environment of the gut is maintained differently than the rest of the internal environment
What are the closest living relatives of animals?
A group of protists called choanoflagellates
what are the most ancient animal phylum?
Porifera (sponges)
When did most major groups of animals start to appear in fossil records?
580 million years ago
What were the first animals in the fossil records? when were they found?
Sponges were found in Doushantuo fossils 580-570 million years ago
When did Cnidarians, ctenophores and other simple forms appear?
Found in Ediacaran fossils 565-544 million years ago
When did Bilaterians appear?
Found in Burgess Shale fossils 525-515 million years ago
Diversity arose in animals mostly because of the evolution of what?
innovative methods for feeding and moving
Feeding in animals can be broken into five major types:
suspension (filter) feeding, deposit feeding, herbivory, predation, parasitism
How do suspension (filter) feeders eat? name some examples of animals that do this
capture food by filtering out particles suspended in water or air; clams, krill, and baleen whales
How do deposit feeders eat? name some examples of animals that do this
they eat their way through a substrate such as soil, plant tissues, animal carcasses, detritus(partially decomposed remains of organisms); earthworms and insect larvae
What do herbivores eat? name some examples herbivores
animals that digest algae or plant tissues by biting, chewing, scraping or sucking; snail, moth, grasshopper, horse
Name the two types of predators
Sit-and-wait(frogs) and stalkers(wolves)
Name the two types of parasites
endoparasites- live inside their hosts (tapeworm)
ectoparasites- live outside their hosts (lice,tick)
What is the stiff structure that resists the forces excerted by muscles
An animal is _____ if eggs or embryos may be laid outside the body
An animal is _____ if eggs may be retained in the female's body during development, with the mother providing nutrition during development
Sponge cells are _____, meaning that an isolated cell has the capacity to develop into a complete adult
Characteristics of Phylum Cnidaria
radially symmetric diploblasts; most are marine but some are freshwater
Have specialized cnidocytes used for prey capture(stinging cells)
Life cycles have a sessile polyp form and a mobile medusa form
Reproduce asexually by budding or fission, and also sexually by swimming gametes
Animals in Phylum Cnidaria
Jellyfish, corals, anemones, hydroids, sea fans
Characteristics of Phylum Ctenophora
Are transparent, ciliated, gelatinous diploblasts
Are predators in marine habitats and are planktonic
Move using rows of cilia
Very abundant in plankton; only about 100 species
Animals in Phylum Ctenophora
Comb Jellies
Characteristics of Phylum Acoelomorpha
Lack a coelom(solid bodies); triploblastic; have no gut, use vacuoles to ingest food
Bilaterally symmetric worms that have distict anterior and posterior ends
Live in marine mud, sand or on algae; swim, glide or burrow using cilia
Feed on detritus and prey on small animals