Biology is FUN!

Platyhelminthes (in Greek, Platy means flat, while minthes means worms) is a phylum composed of three classes of flatworms. The class Turbellaris (planarians) is free living, while the remaining classes including the Trematoda (flukes) and Cestoda (tapeworms) are parasitic.

Members of the phylum are dorsoventrally flattened with a triploblastic body composed od 3 different tissues layers : Ectoderm, Endoderm and the Mesoderm. They are bilaterally symmetrical, meaning that a slice directly through the middle can produce 2 mirror images exactly the same.
This phylum demonstrates an organ-system level of organization. The anterior portion of the body bears most of the sense organ as compared to the posterior of the body. There is a definite head which has a clusters of nerve ganglia forming a simple brain.
Most flatworms have a single opening to the digestive tract which is the gastrovascular cavity.(associates gastro with gastric, and u'll think of food.) Prey is sucked into the gastrovascular cavity by muscular contractions of the reversible pharynx.
They have no respiratory or circulatory systems, but they are simple and flat enough to allow diffusion of oxygen and nutrients to all cells.
Most of them are Hermaphrodites.(lol, we were asked whether we are monoecious or dioecious during biology lesson today, and one answered she's monoecious. hahaha.....everyone burst out laughing like mad.)

Lets have a look on the tapeworms Taenia.....haha......
Tapeworms (class Cestoda)

(1) Tapeworms live in the intestines of vertebrates.They may reach 10 m in length (>30 feet). (2) They have no digestive or nervous tissue.
(3) Tapeworms are harmful because they excrete toxic wastes, absorb nutrients, and may block the intestine.
(4) The segments (proglottids) each contain male and female reproductive organs. Eggs are fertilized from sperm, which often come from other proglottids of the same individual. After fertilization, other organs within the proglottid disintegrate and the proglottid becomes filled with eggs.
(5) The intermediate host are usually pigs or cattle. They can become infected by drinking water contaminated with human feces.
(6) Tapeworms can be passed to humans in undercooked meat, especially pork.

this looked like 'jiu hu see'(cuttlefish snack)......hahaha.....that's why i don't eat cuttlefish

tapeworm lor......

this looks like Spaghetti.........when u eat Spaghetti, musn't think of this pic ya......haha....or else u gonna loose all the appetite for food......

Eewwww!!! tapeworms leaving the body.......i've seen another scene of tapeworm leaving a dead body through the mouth in CSI. hahaha.....that one really BEST!

Our teacher brought a sponge and passes it around to show it to everyone. It's a calcarea sponge. After touching it, I got rashes all over my hand(around the elbow there.....dunno what causes the rashes)

A pic of Obelia.It is from Phylum Cnidaria. It looks like Sushi!(there's another pic which looks more like Sushi, but i can't find it.....lol......)

(ps: i'm not wasting my time doing nonsense, just taking five from study. gtg now, byebye! )
(pps: winnie, good for u, finish exams d!)
(pps: zying if u can guess the name in lee hom's song, i'll belanja u on ur birthday! but only one guess, if tak kena means tarak belanja liao....:p)

-Huifang-