Lab Test 3 Flashcards
(74 cards)
What are the three defining features of animals?
Multicellular
Heterotrophic
Ability to move at some point in their life cycle
What are the three key evolutionary branch points that separate the phyla?
Development of tissues
Symmetry
Body Cavities
Tissues form when _______
two or more cells work together to perform a particular function
Tissues are derived from embryonic germ layers, including:
Ectoderm- develops into skin and protective coating and nerves
Endoderm- develops into digestive and respiratory tract
Mesoderm- skeletal, muscular, cardiovascular, urinary and reproductive systems
Which germ layer develops into the protective outer body covering and nerves
Ectoderm
Which germ layer develops into the digestive and respiratory tract?
Endoderm
Which germ layer develops into the skeletal, muscular, cardiovascular, urinary, and reproductive structures?
Mesoderm
Asymmetry
Occurs when there is no line that divides the body into equal or mirrored halves and occurs in sponges (organisms that do not need to move)
Radial Symmetry
Body cavity can be divided into mirrored halves by more than one line through the median plane.
Best suited for sessile, free floating, or weakly swimming organisms
Ex: sponges, cnidarians, adult echinoderms
Bilateral symmetry
body is divided into mirrored halves by one line through the median plane.
Best for organisms with a distinct head and tail region to allow for FORWARD intentional movement. Ex: flatworms, roundworms, mollusks, arthropods, larval echinoderms, chordates.
________ is any fluid filled space in the animal body that houses and protects internal organs
A body cavity
Acoelomates
Mesodermal cells fill the region between the body wall (ectoderm) and digestive tract (endoderm) completely, leaving NO space for a fluid filled cavity.
Found in flatworms
Pseudocoelomates
Mesodermal cells align themselves against the body wall (ectoderm), leaving space for a Partially lined fluid filled cavity.
Found in roundworms
Eucoelomates
Mesodermal cells align themselves against the body wall (ectoderm) and around the digestive tract (endoderm), leaving a COMPLETELY lined fluid filled cavity.
Found in segmented worms, mollusks, echinoderms, arthropods, chordates
All phyla contain invertebrates except for 1. What phyla is that?
Chordata contains a few invertebrates and the all the vertebrates.
Which phylum includes asymmetrical organisms that lack tissues, germ layers, and coelom, and are sessile as adults. They can reproduce sexually and asexually. Includes Sponges
Porifera
What type of skeletal frame work is each of these?
Hint: Found in sponges
Left picture: Spicules- Rigid framework of calcaneous or siliceous structures
Right picture: Spongin fibers- fibrous structures
What phyla has organisms that have two distinct body forms (polyp and medusa), have organized tissues but lack the mesoderm, and has an incomplete gut? Can reproduce sexually and asexually. Includes hydras, sea anemones, jelly fish, and coral
Cnidarian
What phyla includes organisms that have organ level of organization derived from all three germ layers, but are segmented acoelomates with a gut cavity, reproduce sexually and asexually? Includes flatworms like tapeworms, planarians, and flukes.
Platyhelminthes
What phyla includes organisms that have organ level organization derived from all three germ layers, are pseudocoelomates with gut cavity and pseudocoelom, lack segmentation, and have a complete digestive tract. Includes roundworms like trichina worms, pinworms, and hookworms
Nematoda
What phyla includes organisms that have organ level organization derived from all three germ layers, Eucoelomates with gut cavity and coelom, have cephalization, and only reproduce sexually? They can be terrestrial or aquatic. Includes clams, oysters, scallops, snails, squid, octopus.
Mollusca
What phyla includes organisms that have organ level organization, coelomates (all three germ layers) with cephalization. They have paired jointed appendages, hard exoskeleton, and many have wings. Complete gut, segmentation, bilateral symmetry, sexual or asexual reproduction.
Includes crabs, spiders, tick, scorpions, lobster, crab, insects
Arthropoda
What phyla includes organisms that have organ level organization, coelomates, lack cephalization, have radial symmetry as adults but bilateral as larvae, all are marine. Includes sea stars, urchins, sand dollars, sea cucumbers
Echinodermata
What phyla includes organisms that have organ level organization, coelomates, have cephalization. Complete gut, notochords, postanal tail, and pharyngeal pouches. Includes tunicates, lancelets, fish, reptiles, birds, mammals
Chordata
