Question

Why is Ctenophora considered a minor phylum?

• A. It includes small sized animals.
• B. It includes only few genera.
• C. It does not include animals of economic importance.
• D. It was included earlier in Cnidaria.

Answer 1

The correct option is B It includes only few genera.

• As Ctenophora includes less than 100 species, it is generally considered as a Minor Phylum.
  
• The animals are very similar to Cnidarians in several respects, but also have prominent differences from them.
• The most important differences are the absence of cnidoblasts and the presence of comb plates, in ctenophores.

So, the correct answer is option B.