<span>Bivalvia - Clams, Oysters, Scallops and Mussels.
Cephalopod - Octopi, Squids, Cuttlefish, and the Chambered Nautilus.
Gastropoda - Snails and Slugs.
<span> Polyplacophora - Chitons.</span></span>
It is a tectonic plate, it is constantly moving and shaping the Earth's crust.
C Improper signaling by the right-left axis during development
The first step in the formation of the human embrayo and it is called fertilization.
<h3>What is fertilization?</h3>
The first step in the formation of a human embrayo is called fertilization. The term fertilization has to do with fusion of the male and female gametes to form a zygote.
Hence, the diagram as shown is the first step in the formation of the human embrayo and it is called fertilization.
Learn more about fertilization: brainly.com/question/17991559