Biology 11 Sponges, Roundworms, Flatworms Flashcards

- hermaphroditic: reproduce asexually by budding or by fragmentation (sexual) - they are sessile filter feeders- asymmetrical symmetry - respiration: as water passes through the body wall, sponge cells remove O2 from it and give CO2 into it-spicules form the sponge skeleton - soft sponges have a spongin skeleton- collar cells in sponges make water currents for reproduction, excretion, reproduction,&feeding- in harsh fresh water conditions, gemmules (small collection of cells) are protected with a tough capsule

- have radial symmetry - they may be a poly or a medusa, or alternate between the two forms- they have cnidocytes that discharge stinging nematocytes (capture food)- breaks down into 3 classes:1. Scyphozoa (jellyfish) poly form dominant2. Anthozoa (anenomes&corals) medusa form dominant3. Hydrazoa (hydra) poly form only- have an acoelomate body plan lacking true body systems or organs- tissue layers: ectoderm (outer), endoderm (inner), and noncellular middle layer mesoglea- have a GVC and a nerve net nervous system (primitive)- motile medusa and sessile polyp stage in lives-hermaphroditic: can reproduce asexually (regeneration, budding) or sexually (no self fertilization)

- cause nasty infections in humans-are also parasites of crops, trees, and many mammals

Sexual:- adult sponges produce both eggs and sperm by meiosis- sperm are releases and find another sponge to fertilize-eggs are retained in sponge-zygote develops into a swimming larva- larva leaves the parent sponge& eventually settles on a solid objectAsexual:- regenerate themselves-capable of budding- reproduce by fragmentation

- filter bacteria from the water that passes through them (90% bacteria caught)- can filter 20000 times its own volume of water in one day- they are indicator organisma: lack of sponges in an area indicates pollution-provide shelter and food for other organisms- form symbiotic relationships with bacteria and plant-like protists

GVC: -inner cavity is responsible for digestion, circulation, repiration, and excretion (drawbacks > one opening (anus) and body systems are not separated or specialized)statocysts: - maintain balance ocelli: - detect lightalga symbiont: - makes extra food for host

- there is no brain, or gangila- nerve impulses travel both direction along nerves, unlike human never impulses that travel only one direction

- vertebrates have a backbone ex. sponges, cnidarians, flatworms, roundworms, and all other bilaterally symmetric animals
-invertebrates do not have a backbone

-break into 3 classes:1. Trematoda (flukes)2. Tubellaria ( free-living planarians)lack respritory and circulatory systems3. Cestoda (tapeworms) lack digestive and nervous systems - do not have a circulatory system and gas exchange through body walls- for digestion, they have a GVC and primitive organ systems- for excretion, use GVC and flame cells- have a bilateral nervous system with cephalization-use cilia to move and muscle layers cause an undulation form of motion- hermaphroditic: (do not self fertilize) regeneration and fragmentation- carnivores and scavengers

1. have a modified epidermis "teguement" which protects against digestive enzymes and the immune system of the host2. adapted to constant internal environments3. flat and long, which maximizes surface area for absorption of food (7m long in humans)4. scolex with 4 suckers to attach to intestine of host-produce hundreds of thousands of eggs and sperm

Intermediate directly eats larvae, primary eats intermediate and then gets tapeworms

- Pseudocoelomate body plan "tube within a tube"- bilateral symmetry- basic cephalization- unsegmented- respirate circulate, and excrete through body walls- hydrostatic skeleton (results from high internal fluid pressure)- only longitudial muscles (mesoderm)- parasitic species of nematodes: trichina worms, hookworms, ascarids, pinworms, filarias

- decompsers: recle cteria, fung, and decaying organic matter back into soil

- cause nasty infections in humans-are also parasites of crops, trees, and many mammals