During embryonic development, if the anus develops before the mouth, the organism is a

If the anus develops before the mouth, the organism is a deuterostome, which means  "second mouth." It is a sister clade of Protostomia, with which it forms the Nephrozoa clade. The proterostomic develop the mouth first. Deuterostomes are also known as enterocoelomates because their coelom develops through enterocoely. 

Explanation:

https://www.mun.ca/biology/scarr/Protostomes_vs_Deuterostomes.html

https://en.wikipedia.org/wiki/Deuterostome

https://ucmp.berkeley.edu/phyla/deuterostomia.html

https://www.weegy.com/?ConversationId=6CB3C815

x would be the most and the least would be y because there are more fruit   and seeds than flock z has insects