Assertion [A]: Platyhelminths are acoelomates.
Reason [R]: Platyhelminths develop three primary germ layers during early embryogenesis.
Assertion [A]: Platyhelminths are acoelomates.
Reason [R]: Platyhelminths develop three primary germ layers during early embryogenesis.
The correct option is A Assertion [A] is True and Reason [R] is False.
In platyhelminths, spongy connective tissue (mesenchyme) constitutes the so-called parenchyma and fills the space between organs. So there is no space available for the formation of coelom, as a result, they are acoelomates. The external appearance of flatworms (dorsoventrally flattened) is an indication of their acoelomate nature. This feature is also an adaptation for their parasitic mode of nutrition. Platyhelminths are triploblastic, indicating that they develop three primary germ layers during early embryogenesis. This is another common feature of all flatworms; it is not a reason for their acoelomate nature.
Assertion [A] is True and Reason [R] is False.
In platyhelminths, spongy connective tissue (mesenchyme) constitutes the so-called parenchyma and fills the space between organs. So there is no space available for the formation of coelom, as a result, they are acoelomates. The external appearance of flatworms (dorsoventrally flattened) is an indication of their acoelomate nature. This feature is also an adaptation for their parasitic mode of nutrition. Platyhelminths are triploblastic, indicating that they develop three primary germ layers during early embryogenesis. This is another common feature of all flatworms; it is not a reason for their acoelomate nature.
