$Monocystis$ belongs to the order:

Match List $I$ with List $II$ :

List $I$	List $II$
$A$. Pleurobrachia	$I$. Mollusca
$B$. Radula	$II$. Ctenophora
$C$. Stomochord	$III$. Osteichthyes
$D$. Air bladder	$IV$. Hemichordata

Choose the correct answer from the options given below :

Which of the following statements are true or false?
$(i)$ Suckers are found in liver fluke.
$(ii)$ In Arthropods,fertilization is external.
$(iii)$ Chordata is divided into $4$ subphyla.
$(iv)$ Water vascular system is present in Hemichordata.

$A.$ Animals are multicellular organisms composed of eukaryotic cells.
$R.$ Sponges do not perform photosynthesis and obtain nutrition by absorption.

An animal that is initially male and then changes to female is called:

Which feature is common among leech,cockroach,and scorpion?