Question

Flame cells of flatworms help in
i) Osmoregulation
ii) Digestion
iii) Reproduction
iv) Excretion
v) Bioluminescence
A. (ii) Only is correct
B. (i) and (iv) are correct
C. (iii) only is correct
D. (i) and (v) are correct
E. (iv) and (v) are correct

Answer 1

Hint: A flame cell is a specialized excretory cell present in the simplest freshwater invertebrates like flatworms. Flame cells function like a kidney as well as they remove waste materials. Bundles of flame cells are known as protonephridia. The function of these cells is to regulate the osmotic pressure along with it; they maintain ionic balance.

Complete answer:
Flame cells of flatworms, also known as rotifers as well as nemerteans; these are the simplest animals to have a dedicated excretory system. Flame cells function just like a human kidney as they perform the function of removing waste materials.
The flame cell has a nucleated cell body that is with a "cup-shaped" projection, along with a flagella covering the inner surface of the cup. The beating of these flagella resemble a flame, providing the cell its name. The cup is attached to the tube cell, whose inner surface is also coated in cilia that help to move liquid through the tube cell. The tube opens externally through a nephropore, or, in the trematoda, into an excretory bladder.
The key function of these cells is to regulate the osmotic pressure of the worm, as well as maintain its ionic balance. Microvilli in the tube cell may be used to reabsorb some ions.
 Option – A. – Is incorrect as Flame cells do not help in Digestion process.
Option – B – is the right answer to the question as both Osmoregulation as well as Excretion are functions of Flat cells
Option – C – Is not the right answer as Reproduction is not affected by Flat cells
Option – D – Is not correct as Osmoregulation is done by Flat cells but bioluminescence is not.
Option – E – Is not right as flat cells do not help in either excretion and Bioluminescence.

So the correct answer to the question is option- B “(i) and (iv) are correct”.

Note: Molecules enter the tubule in tube cells through the gap present between the flame cell and tube cell for excretion. Flame cells are ciliated cells which form a part of the excretory as well as osmoregulatory systems of Platyhelminthes, rotifers, and nemertine worms.