Which among the following statements is incorrect about ctenophores?a)...
CtenophoresCtenophores, also known as comb jellies, are marine invertebrates that belong to the phylum Ctenophora. They are characterized by their unique features and behavior. Let's discuss the given statements and identify the incorrect one.
Statement a) Ctenophores are radially symmetrical
Ctenophores exhibit radial symmetry, meaning their body parts are arranged around a central axis. This symmetry allows them to have multiple planes of symmetry, making them similar from any direction. They lack the bilateral symmetry present in many other organisms.
Statement b) They are diploblastic
Diploblastic organisms have two primary germ layers during embryonic development: the ectoderm and the endoderm. However, ctenophores are not diploblastic; they are actually triploblastic. Triploblastic animals have three germ layers, including the mesoderm, which lies between the ectoderm and endoderm. Ctenophores possess all three germ layers, making them triploblastic.
Statement c) They reproduce both sexually and asexually
This statement is correct. Ctenophores can reproduce both sexually and asexually. Asexual reproduction in ctenophores occurs through budding, where a small portion of the parent's body forms a new individual. Sexual reproduction involves the release of eggs and sperm into the water. Fertilization occurs externally, leading to the development of a new individual.
Statement d) They have ciliated comb plates on their body
This statement is also correct. One of the defining features of ctenophores is the presence of ciliated comb plates, which are rows of specialized cells called ctenes. These ctenes contain cilia that beat in a coordinated manner, allowing ctenophores to move through the water. The cilia also create beautiful iridescent patterns of light, giving ctenophores their characteristic shimmering appearance.
Therefore, the incorrect statement is option c) They reproduce both sexually and asexually. Ctenophores do reproduce both sexually and asexually, making option c) incorrect.