Question

1. which of the following is a small barbed harpoon organelle that contains toxins found in cnidocytes of cnidarians? planula nematocyst tentacles basal disk

Explanation:

To solve this, we analyze each option:

• Planula: A larval form of cnidarians, not a harpoon - like organelle.
• Nematocyst: It is a specialized organelle in cnidocytes of cnidarians. It is a small, barbed harpoon - like structure that contains toxins used for defense and capturing prey.
• Tentacles: These are appendages of cnidarians used for various functions like capturing prey, but they are not the harpoon - like organelle with toxins.
• Basal disk: It is a structure in some cnidarians (like hydras) used for attachment, not the toxin - containing harpoon - like organelle.

Answer:

B. nematocyst