Which of the following swim by ciliary action?
A. Adult Fasciola
B. Miracidium redia, and cercaria of Fasciola
C. Miracidium larva of Fasciola
D. Redia larva of Fasciola
C. Miracidium larva of Fasciola
The organisms that swim by ciliary action are the miracidium and redia larva of Fasciola. So the correct answer is B. Miracidium redia, and cercaria of Fasciola.
To find out which of the options swim by ciliary action, we need to understand what ciliary action is. Ciliary action refers to the movement of tiny hair-like structures called cilia in order to generate a flow of fluid. In the context of swimming, ciliary action refers to the use of cilia to create a wave-like motion that propels an organism through water.
Now, let's examine the options given:
A. Adult Fasciola: Adult Fasciola refers to the mature stage of the parasite Fasciola, also known as liver fluke. Adult Fasciola typically reside within the liver and bile ducts of their hosts. They do not use ciliary action for swimming, but rather rely on muscular movement to crawl or wriggle.
B. Miracidium, Redia, and Cercaria of Fasciola: Miracidium, Redia, and Cercaria are different larval stages of the Fasciola parasite. The miracidium larva is the early free-swimming stage, the redia larva is the intermediate stage, and the cercaria larva is the final, infective stage. Ciliary action is indeed involved in the swimming of these larvae. The beating of cilia helps propel them through water.
C. Miracidium larva of Fasciola: As mentioned earlier, the miracidium larva of Fasciola swims by ciliary action. This larval stage is capable of actively moving through water using its cilia.
D. Redia larva of Fasciola: Similar to the miracidium larva, the redia larva of Fasciola also swims by ciliary action. The beating of cilia assists in the locomotion of this larval stage.
In conclusion, both the Miracidium and Redia larvae of Fasciola swim by ciliary action. Therefore, the correct answer to the question is options B and D.