A. In prophase I, tetrads of homologous chromosomes form and crossing over occurs
hope this helps :)
<span>elongation ^^ *hugs*</span>
<span>Echinoderms are marine invertebrates, they dwell under the sea unlike that of others that mostly live in land.
<em>Hope this helps:)</em></span>
Answer:
This phylum can be segregated into seven classes: Aplacophora, Monoplacophora, Polyplacophora, Bivalvia, Gastropoda, Cephalopoda, and Scaphopoda.