Question

Metanephridia of Earthworm are ____________.

• A. Homologous to flame cells
• B. Analogous to flame cells
• C. Connected with respiration
• D. Helpful in copulation

Answer 1

The correct option is B Analogous to flame cells

Planaria are flatworms that live in fresh water. Their excretory system consists of two tubules connected to a highly branched duct system. The cells in the tubules are called flame cells (or protonephridia) because they have a cluster of cilia that looks like a flickering flame when viewed under the microscope.

On the other hand, Earthworms (annelids) have slightly more evolved excretory structures called nephridia. A pair of nephridia is present on each segment of the earthworm. They are similar to flame cells in that they have a tubule with cilia.

So, the correct answer is 'Analogous to flame cells'.