which germ layers does a diploblastic animal have?
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Diploblastic organisms (eg. coelenterates) have two layers, ectoderm and endoderm.
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Egg, larva, pupa and adult.
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The three terrestrial classes that give rise to the four extra embryonic membranes are mammals, birds, and reptiles.\n\nThe four membranes are:\n\nChorion. The outermost of the two fetal membranes - the amnion is the innermost --. which together surround the embryo. The chorion develops villi (vascular fingers) and gives rise to the placenta. In Greek, the word "chorion" means "skin or leather."\n\nAmnion. The amnion is a membranous sac which surrounds and protects the embryo. It is developed in reptiles, birds, and mammals, which are hence called 'Amniota'; but not in amphibia and fishes, which are consequently termed 'Anamnia'.\n\nAllantois. An extra-embryonic membrane of reptiles, birds, and mammals arising as a pouch, or sac, from the hindgut. In reptiles and birds it expands greatly between two other membranes, the amnion and chorion, to serve as a temporary respiratory organ while its cavity stores fetal excretions. In mammals other than marsupials the allantois is intimately associated with the chorion, contributing blood vessels to that structure as it forms—in conjunction with the endometrium, or mucosal lining, of the uterus—the placenta. \n\nYolk Sac. A membranous sac attached to an embryo, providing early nourishment in the form of yolk in bony fishes, sharks, reptiles, birds, and primitive mammals and functioning as the circulatory system of the human embryo before internal circulation begins.
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Externally they have spines, tube feet, pedicellaria, all of which are attached to the calcium carbonate test. The muscles attached to all these parts allow movement of these parts. At the ventral mouth reveals their "aristotle's lantern" aka their fancy mouth-mouthparts designed much like garbage disposal blades.  The 5 white teeth set up like a grinding-beak can eat away at the kelp bed.  Inside they have some organs, mostly reproductive organs that hold their gametes between spawnings-breedings.  They also have a digestive system with an anus. They have a water vascular system inside which circulates water for a hydraulic pump, NOT blood!
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http://en.wikipedia.org/wiki/Parelaphostrongylus_tenuis\n\nMorphology\n\nRoundworms are triploblastic protostomes with a complete digestive system. Roundworms have no circulatory or respiratory systems so they use diffusion to breathe and for circulation of substances around their body. They are thin and are round in cross section, though they are actually bilaterally symmetric. Nematodes are one of the simplest animal groups to have a complete digestive system, with a separate orifice for food intake and waste excretion, a pattern followed by all subsequent, more complex animals. The body cavity is a pseudocoel (persistent blastula), which lacks the muscles of coelomate animals used to force food down the digestive tract. Nematodes thus depend on internal/external pressures and body movement to move food through their digestive tracts. The mouth is often surrounded by various flaps or projections used in feeding and sensation. The portion of the body past the anus or cloaca is called the "tail." The epidermis secretes a layered cuticle made of keratin that protects the body from drying out, from digestive juices, or from other harsh environments, as well as in some forms sporting projections such as cilia that aid in locomotion. Although this cuticle allows movement and shape changes via a hydrostatic skeletal system, it is very inelastic so does not allow the volume of the worm to increase. Therefore, as the worm grows, it has to moult and form new cuticles. The cuticles don't allow volume to increase so as to keep hydrostatic pressure inside the organism very high. For this reason, the roundworms do not possess circular muscles (just longitudinal ones) as they're not required. This hydrostatic pressure is the reason the roundworms are round.\nMost free-living nematodes are microscopic, though a few parasitic forms can grow to several meters in length. There are no circular muscles, so the body can only undulate from side to side. Contact with solid objects is necessary for locomotion; its thrashing motions vary from mostly to completely ineffective at swimming.\nRoundworms generally eat bacteria, algae, fungi and protozoans, although some are filter feeders. Excretion is through a separate excretory pore.\nReproduction is usually sexual. Males are usually smaller than females (often very much smaller) and often have a characteristically bent tail for holding the female for copulation. During copulation, one or more chitinized spicules move out of the cloaca and are inserted into genital pore of the female. Amoeboid sperm crawl along the spicule into the female worm.\nEggs may be embryonated or unembryonated when passed by the female, meaning that their fertilized eggs may not yet be developed. In free-living roundworms, the eggs hatch into larva, which eventually grow into adults; in parasitic roundworms, the life cycle is often much more complicated.\nRoundworms have a simple nervous system, with a main nerve cord running along the ventral side. Sensory structures at the anterior end are called amphids, while sensory structures at the posterior end are called phasmids.\n\nhttp://en.wikipedia.org/wiki/Nematode\n\n\nHope that helps!
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They are all prokaryotes, some may have a thick cell wall made of peptodiglycan.  They can live in extremely acidic, basic, hot, cold, salty, or wet environments.
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egg > larva(catapillar) > pupa(in the cocoon) > butterfly
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go to the website for the Natural History Museum in Washington DC.  I took my kids there last year and they have skeletal structures for just about any animal you can think of.  Check it out.
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Diploid. All cells in the body that have chromosomes, except germ line cells, are diploid. One set of chromosomes from each parent.
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Flatworms contain structures called flame cells.\nRoundworms contain structures called lateral lines and an excretory pore.\nSegmented worms contain tube-like nephridia.\nClams also contain nephridia\nArthropods contain different organs(green glands and malpighian tubules).
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>>>>>> Only vertebrates have teeth.\n\nThat isn't true. Lampreys have teeth and are not vertebrates. The radulae of many molluscs also have teeth.\n\nThe rest of your answer was spot on though.
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The following link has info about habitat, size, pics, etc.\n\nhttp://www.discoverlife.org/nh/tx/Vertebrata/Mammalia/Dipodidae/Zapus/hudsonius/
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Just one. \n\nVery few animals produce more than one offspring per egg.
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Scorpions are among the few arthropods that don't lay eggs. In some, the female can store sperm until she is ready to fertilise her eggs. The fertilised eggs develop into embryos in brood chambers within the mother's body. Nutrients are transferred from the mother's digestive system to the embryos, but not through a placenta like in mammals. "Gestation" is quite long: it can take several months to more than a year before the young are "born". In some, the babies are fully formed but their skin remains white and soft until their second moult. In others, the babies look like fat white maggots with tiny pincers. They only look like scorpions after their second moult, when they get the right shape and their exoskeleton turns dark and hard
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The hard, rigid outer covering of certain animals is called a shell. While many animals, particularly those that live in the sea, produce exoskeletons, usually only those of mollusks are considered to be shells. It is sometimes erroneously claimed that shells are made of chitin, but these are unrelated materials (except for their hardness and use as a covering by animals).\n\nThe shell is usually made of nacre, an organic mixture of outer layers of horny conchiolin (a scleroprotein), followed by an intermediate layer of calcite oraragonite, and then a layer of calcium carbonate (CaCO3) in the form of platy crystals.\n\nNacre is secreted by the epithelial cells (formed by the germ layer ectoderm) of the mantle tissue of certain species of mollusk. Mollusk blood is rich in a liquid form of calcium. In these mollusks the calcium is concentrated out from the blood where it can crystallize as calcium carbonate. The individual crystals of each layer differ in shape and orientation. Nacre is continually deposited onto the inner surface of the animal's shell (the iridescent nacreous layer also known as mother of pearl), both as a means to smoothen the shell itself and as a defense against parasitic organisms and damaging detritus.\n\n \nVarious seashellsWhen a mollusk is invaded by a parasite or is irritated by a foreign object that the animal cannot eject, a process known as encystation entombs the offending entity in successive, concentric layers of nacre. This process eventually forms what we call pearls and continues for as long as the mollusk lives.\n\nShells are very durable and outlast the otherwise soft-bodied animals that produce them by a very long time. Large amounts of shells may form sediment and become compressed into limestone. Shells that wash up on beaches are called seashells, and are collected by some enthusiasts
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There are three living genera of Monotremes, which are the group of mammals that lay eggs:\n\nThe Platypus (Ornithorhyncus) of Australia\nThe Short-nosed Echidna (Tachyglossus) of Australia\nThe Long-nosed Echidna (Zaglossus) of Australia and New Guinea\n\nThere used to be a lot more species of egg-laying mammals, but these are the only ones that survive today.
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courtesy of Encarta Encyclopedia Online!\nThe phylum of Cnidarians, or Coelenterates, is a phylum within Kingdom Animalia and consists of hydras, jellyfish, sea anemones, and corals. This phylum consists of over 9000 species. All cnidarians are radially symmetrical, meaning that they have a central axis and are symmetrical all around it. Their level of complexity is right above that of sponges, among the Metazoa, or many cells animals. In all cnidarians, the mouth leads directly into the gastrovascular cavity, a digestive cavity. This cavity is filled with fluid, which services internal cells, provides body support, and helps maintain structure. There is no anus, and so excess food and waste products must exit through the mouth. As a result, the digestive system of cnidarians is considered incomplete. Another characteristic of cnidarians is that they all have two layers of living tissue. The first layer of living tissue is known as the dermis, and the second layer is know as the gastordermis. The dermis is the outer layer, and the gastordermis is the inner layer which forms the body cavity. A gelatinous layer called mesoglea separates these two layers. Also, in all cnidarians, nearly all functions are performed by individual tissues, not organs, despite the fact that a very small number of them do contain organs. Another characteristic of cnidarians is that they all have two layers of living tissue. The first layer of living tissue is known as the dermis, and the second layer is know as the gastordermis. The dermis is the outer layer, and the gastordermis is the inner layer which forms the body cavity. A gelatinous layer called mesoglea separates these two layers. Also, in all cnidarians, nearly all functions are performed by individual tissues, not organs, despite the fact that a very small number of them do contain organs.\n\nPhylum Cnidaria includes the following classes:\n\n-Class Schphozoa (The jellyfish, or jellies)\n-Class Hydrozoa (Diverse polyps, including hydras)\n-Class Cubozoa (A minor tropical class with cuboidal swimming cups)\n-Class Anthozoa (Sea anemones, corals)