Question

Open Circulatory system is present in:

• A. Palaemon, Nereis, Balanoglossus
• B. Hirudinaria, Bombyx, Salpa
• C. Anopheles, Limax, Limulus
• D. Pheretima, Musca, Pila

Answer 1

The Correct Option is C

To determine which of the given options contains organisms with an open circulatory system, we first need to understand what an open circulatory system is.

Open Circulatory System: In an open circulatory system, the blood is not completely contained within blood vessels. Instead, it flows freely through cavities and directly bathes organs in a fluid called hemolymph. This type of circulatory system is common in invertebrates.

Explanation of Options:

1. Palaemon, Nereis, Balanoglossus - Palaemon is a prawn, typically having an open circulatory system. However, Nereis (a type of annelid) and Balanoglossus (a hemichordate) do not possess an open circulatory system. They have evolved different structures.
2. Hirudinaria, Bombyx, Salpa - Hirudinaria is a type of leech (annelid) and has a closed circulatory system. Bombyx (silkworm) has a simple open circulatory system, while Salpa (a tunicate) also does not have an open circulatory system.
3. Anopheles, Limax, Limulus - Anopheles is a mosquito, Limax is a type of slug, and Limulus is a horseshoe crab. All three organisms have an open circulatory system, where hemolymph is circulated directly around the tissues.
4. Pheretima, Musca, Pila - Pheretima (earthworm) has a closed circulatory system. Musca (housefly) and Pila (a type of mollusk) both have open circulatory systems, but not all organisms in this option follow the pattern.

Conclusion: The organisms in the option Anopheles, Limax, Limulus all possess an open circulatory system, making it the correct answer.