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42 Cards in this Set
- Front
- Back
What are the four features that define an animal's body plan?
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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
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Animals whose embyros have two tissues or germ layers: ectoderm and endoderm
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Diploblasts
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Animals whose embryos have three tissues or germ layers: ectoderm, endoderm and mesoderm
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Triploblasts
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What is cephalization?
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the evolution of a head, or anterior region, where structures for feeding, sensing the environment and processing information are concentrated (allowed by bilateral symmetry)
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What is an internal fluid-filled body cavity that creates a medium for circulation and space for internal organs called?
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coelom
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what is a 'false coelom' that is not lined with mesoderm on both sides?
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pseudocoelom
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what is a fluid-filled chamber that allows an animal to move even without fins or limbs?
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hydrostatic skeleton
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_____ have no body cavity
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acoelomates
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______ have a body cavity partially lined with mesoderm
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pseudocoelomates
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______ have a body cavity completely lined with mesoderm
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coelomates
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The group Bilatera can be divided into which groups?
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Protostomes and Deuterostomes
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Arthropods, mollusks and segmented worms are all ____
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protostomes
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vertebrates and echinoderms are both ______
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deuterostomes
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what events in early development differ in protostomes and deuterostomes?
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cleavage, gastrulation and coelom formation
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What is different about the cleavage formation between protostomes and deuterostomes?
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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 |
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What is different about the gastrulation process between protostomes and deuterostomes?
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Protostomes- blastopore becomes the mouth
Deuterostomes- blastopore ecomes the anus |
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What is gastrulation?
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the ball of cells formed by cleavage invaginates to form gut and embryonic tissue layers
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What is cleavage?
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a rapid series of mitotic divisions that occurs in the absence of growth
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What is different about the coelom formation between protostomes and deuterostomes?
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Protostomes- the block of solid mesoderm splits open to form coelom
Deuterostomes- messoderm pockets pinch off the gut to form coelom |
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Describe the tube-within-a-tube design
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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
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What are the closest living relatives of animals?
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A group of protists called choanoflagellates
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what are the most ancient animal phylum?
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Porifera (sponges)
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When did most major groups of animals start to appear in fossil records?
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580 million years ago
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What were the first animals in the fossil records? when were they found?
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Sponges were found in Doushantuo fossils 580-570 million years ago
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When did Cnidarians, ctenophores and other simple forms appear?
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Found in Ediacaran fossils 565-544 million years ago
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When did Bilaterians appear?
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Found in Burgess Shale fossils 525-515 million years ago
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Diversity arose in animals mostly because of the evolution of what?
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innovative methods for feeding and moving
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Feeding in animals can be broken into five major types:
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suspension (filter) feeding, deposit feeding, herbivory, predation, parasitism
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How do suspension (filter) feeders eat? name some examples of animals that do this
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capture food by filtering out particles suspended in water or air; clams, krill, and baleen whales
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How do deposit feeders eat? name some examples of animals that do this
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they eat their way through a substrate such as soil, plant tissues, animal carcasses, detritus(partially decomposed remains of organisms); earthworms and insect larvae
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What do herbivores eat? name some examples herbivores
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animals that digest algae or plant tissues by biting, chewing, scraping or sucking; snail, moth, grasshopper, horse
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Name the two types of predators
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Sit-and-wait(frogs) and stalkers(wolves)
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Name the two types of parasites
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endoparasites- live inside their hosts (tapeworm)
ectoparasites- live outside their hosts (lice,tick) |
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What is the stiff structure that resists the forces excerted by muscles
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skeleton
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An animal is _____ if eggs or embryos may be laid outside the body
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oviparous
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An animal is _____ if eggs may be retained in the female's body during development, with the mother providing nutrition during development
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viviparous
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Sponge cells are _____, meaning that an isolated cell has the capacity to develop into a complete adult
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totipotent
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Characteristics of Phylum Cnidaria
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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 |
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Animals in Phylum Cnidaria
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Jellyfish, corals, anemones, hydroids, sea fans
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Characteristics of Phylum Ctenophora
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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 |
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Animals in Phylum Ctenophora
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Comb Jellies
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Characteristics of Phylum Acoelomorpha
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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 |