Read the following statements:

a. Polyp is sessile and cylindrical form like Adamsia.
b. Medusa is umbrella-shaped and free-living like Aurelia.
c. Polyp produce medusae sexually and medusae form the polyp asexually (e.g.: Obelia).
d. Metagenesis is seen in jellyfish.

Find out the incorrect statements.

$\text{Incorrect statements}$

$\text{Statement c:}$ Polyp produce medusae sexually and medusae form the polyp asexually (eg: Obelia).

$\text{Elaboration :}$
Obelia (Sea fur) belongs to the class Hydrozoa of the kingdom Cnidaria that shows polyp (cylindrical) as well as medusa (umbrella-shaped) form in its life cycle.

$\text{Statement d:}$ Metagenesis is seen in jellyfish.

$\text{Elaboration :}$
Cnidarians, which exhibit both the types of body forms, polyp (cylindrical) and medusa (umbrella-shaped), exhibit metagenesis. Aurelia (jelly-fish) only shows umbrella-shaped (medusa) form and therefore, does not exhibit metagenesis. Hence, statement ‘d’ is incorrect.

$\text{Final answer}$

$d. ~c, d$