Question

Bladderworm/cysticercus is the larval stage of

• A. tapeworm
• B. roundworm
• C. pinworm
• D. liver fluke.

Answer 1

The Correct Option is A

The problem at hand is to determine the organism for which the bladderworm, also known as cysticercus, is the larval stage. The options provided are tapeworm, roundworm, pinworm, and liver fluke.

To solve this, we must understand the life cycle and larval forms of these parasites. Let's examine each option:

1. Tapeworm: Tapeworms are parasitic worms, and their larval stage is known as cysticercus or bladderworm. This larva is typically found in the intermediate hosts of the tapeworm, such as cattle or pigs, and develops into an adult tapeworm when it reaches the definitive host, usually a human. This matches the given scenario.
2. Roundworm: Unlike tapeworms, roundworms have different larval stages, like the L1 to L4 stages in their development cycle. They do not have a stage known as cysticercus or bladderworm.
3. Pinworm: The lifecycle of a pinworm is straightforward and involves egg, larval, and adult stages. There is no cysticercus stage in the pinworm lifecycle.
4. Liver fluke: Liver flukes have a complex life cycle involving multiple larval stages, such as miracidia and cercariae, but not a cysticercus or bladderworm stage.

Based on the information above, the correct answer is that a bladderworm or cysticercus is the larval stage of a tapeworm. The larval form resides in intermediate hosts and awaits a predator to become its definitive host, where it can mature into a complete tapeworm.