Answer:
D
Explanation:
it has to be D because its talking about "how does a volcanic ash affect water systems"
Organism in which the embryonic blastopore becomes its anus Deuterostome
<u>Explanation:</u>
The term Deuterostome refers to second mouth. The first opening which is called blastpore becomes its anus in deuterostomes. In protostomes, this first opening will be the mouth. The other name given to these Deuterostomes enterocoelomates. It is the enterocoely from which the coelom of Deuterostom starts emerging and growing.
Chordata, Echinodermata, Hemichordata are the classes of deuterostomes:. The zygote is the one that gets developed first in protostomes and deuterostomes.Radial cleavage occurs in deuterostom in which the division of cells lies either in parallel direction or in perpendicular direction with respect to the polar axis.
Already answered in pm ;P
