https://padlet.com/20191911/wk61ue5t1jeq From Phylum Platyhelminthes en-us 2019-02-24 17:35:18 UTC 2025-12-23 07:04:59 UTC hello@padlet.com 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334616812 Domain: Eukarya
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Turbellaria ]]> 2019-02-24 20:04:13 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334616812 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334616887 Turbellarian flatworms (planarians) are mostly free living (non-parasitic) and aquatic. They are mostly hermaphroditic. They are usually ciliated for movement.]]> 2019-02-24 20:04:48 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334616887 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334616899 Domain: Eukarya
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Turbellaria
Order: Tricladida
Family: Dugesiidae
Genus: Dugesia
Species: D. japonica]]> 2019-02-24 20:04:55 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334616899 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334619851 Planarians have bilateral symmetry. Bilateral symmetry is usual one indicator of an active organism.]]> 2019-02-24 20:24:35 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334619851 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334620454 Planarians are triploblastic, meaning that they have three germcell layers. Those layers are the endoderm, mesoderm, and ectoderm. ]]> 2019-02-24 20:28:52 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334620454 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621773 Planarians don't have a formal respiratory system. Instead, they rely on diffusion to exchange gases from cell to cell. Some important structures that aid in diffusion are:
1) Protonephridia - networks of fine tubules that run the length of the planarian along its side.
2) Flame cells - fine side branches of the tubules that originate in the parenchyma as tiny enlargements
3) Nephridiopore - small pores/openings on the outside of a planarian's body that merge with the tubules.]]> 2019-02-24 20:39:27 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621773 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621783 Planarians don't have a formal circulatory system. Instead, they rely on diffusion to exchange gases from cell to cell.]]> 2019-02-24 20:39:32 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621783 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621823 Planarians have no skeleton. They are masses of muscle and tissue.]]> 2019-02-24 20:39:49 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621823 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621846 Nervous tissues in most planarians consists of a sub-epidermal nerve net. Lateral branches called commissures connect the nerve cords. This results in a ladder-like organizational appearance. Planarians also have primitive brains.]]> 2019-02-24 20:39:57 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621846 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621867 Actual digestion is partially extracellular. Phayngeal glands secrete enzymes that break down food to be taken in by the pharynx. In the digestive cavity, phagocytic cells absorb the food. Digestion s completed in intracellular vesicles.]]> 2019-02-24 20:40:03 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621867 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621874 They have no formal excretory system due to a lack of anus. Therefore, the digestive system of a planarian is incomplete due to the presence of a mouth but absence of an anus. In order to secret waste, the waste passes through canals and ciliated flame cells. Any remaining nutrients are absorbed by the planarian and waste exits through the flame cells.]]> 2019-02-24 20:40:06 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621874 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621905 Planarians have two types of reproduction: sexual and asexual.]]> 2019-02-24 20:40:17 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621905 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621925 Rhabdites assist in defense by providing a protective layer over the organism's body. Planarians also have regenerative properties that allow them to regrow necessary structures.]]> 2019-02-24 20:40:24 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621925 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621945 Planarians use cilia, aided by mucus, to move across lake and sea floors. Muscle undulations help them glide across rocks and other surfaces.]]> 2019-02-24 20:40:33 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621945 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621954 Special structures help aid planarians during their day-to-day lives. This could include eating, walking, or getting oxygen.]]> 2019-02-24 20:40:39 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621954 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334621980 2019-02-24 20:40:47 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334621980 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334622727 The muscles that help to propel planarians forward lie just under the ectoderm. the muscle cells have two layers. The outer layer moves in a circular direction while the inner layer runs in a straight pattern. Muscles also run vertically, allowing for bending and twisting.]]> 2019-02-24 20:45:08 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334622727 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334623071 The outer layer of a planarian is usually ciliated for movement, sometimes consisting of microvilli.]]> 2019-02-24 20:47:22 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334623071 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334623085 The innermost layer of a planarian consists of a single layer. This layer makes up the digestive cavity. It secretes enzymes that aid in digestion and absorbs digestion's end products.]]> 2019-02-24 20:47:26 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334623085 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334623420 Connective tissues separate the mesoderm from the epidermis. The tissues derived from the mesoderm are mostly muscle.]]> 2019-02-24 20:49:54 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334623420 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334623925 Locomotion in a planarian is the result of two things.
1) the gliding is both muscular and ciliary
2) the rapid movements pass from the head back to propel the animal forward; the movements are muscular]]> 2019-02-24 20:53:29 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334623925 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334624745 Food is ingested by the pharynx, a ciliated tube or a complex developed from folded muscle layers. If a planarian has the tube, it is kept in a sheath that can project out for feeding on small invertebrates or scavenge.]]> 2019-02-24 20:59:23 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334624745 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334625450 Rhabdites are rodlike cells that swell and form a protective mucous sheath around the body in case of predation.
Adhesive glands produce a chemical that attaches the planarians to the floor.
Releaser glands secrete a chemical to dissolve the attachment, as needed.]]> 2019-02-24 21:04:27 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334625450 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334629949 There are three main groups neurons in a planarian: sensory, motor, and association. Auricles are  sensory lobes that project from the head to sense stimuli. Ocelli are eyespots that allow the animal to see light.]]> 2019-02-24 21:37:01 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334629949 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334630546 Planarians asexually reproduce through transverse fission. Fission usually begins as a constriction behind the pharynx. The two or more animals resulting from fission are called zooids. If any zooids are missing parts, they begin regenerating those missing parts after separation. Zooids may may remain attached until fully formed; once formed, they detach as independent individuals.]]> 2019-02-24 21:41:41 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334630546 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334630558 Planarians are monoecious, so they have both male and female reproductive organs. Despite being monoeicious and capable of self-fertilization, many planarians still cross-fertilize to create more genetic diversity. During cross-fertilization, the penis of both planarians insert into the other and secrete sperm. Fertilization occurs in the ovaries, after passing through the genital chamber and oviducts. Fertilized eggs are kept in cocoons to protect them from the elements.]]> 2019-02-24 21:41:46 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334630558 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334656713 The development of planarians is direct, like humans. They go from embryos into adults. Some planarians have a free-swimming larva stage called a Muller's larva. These larva have ciliated extensions for feeding and movement. They eventually settle to become young planarians.]]> 2019-02-25 00:55:30 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334656713 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334657094 Cilia themselves are very helpful to planarians. Not only do they help the organisms move, but they help grip food and beat fluid into tubules by creating negative pressure.]]> 2019-02-25 00:57:48 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334657094 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334657886 2019-02-25 01:02:31 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334657886 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334658069 2019-02-25 01:03:42 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334658069 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334659575 2019-02-25 01:12:14 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334659575 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/334659849 2019-02-25 01:13:43 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/334659849 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/335020130 2019-02-25 18:32:50 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/335020130 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/335023690 2019-02-25 18:38:51 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/335023690 20191911 https://padlet.com/20191911/wk61ue5t1jeq/wish/335534858 2019-02-26 18:06:46 UTC https://padlet.com/20191911/wk61ue5t1jeq/wish/335534858