Final answer:
The correct statement about animal body plans is that development in all animals is determined by the unique family of Hox genes (or other similar homeobox genes). Not all triploblastic animals possess a coelom, and in protostomes, the blastopore develops into the mouth, while in deuterostomes, it becomes the anus.
Step-by-step explanation:
Select the correct statement(s) about animal body plans. Select all that apply. Select all that apply. All triploblastic animals possess a coelom. Development in all animals is determined by the unique family of Hox genes (or other similar homeobox genes). In both protostomes and deuterostomes, the blastopore develops into the mouth.
The correct statements based on the provided information are that: Development in all animals is determined by the unique family of Hox genes (or other similar homeobox genes). This is true because the Hox genes are a group of related genes that control the body plan of an embryo along the head-tail axis. After the embryonic segments have formed, Hox proteins determine the type of segment structures (e.g., legs, antennae, and wings in fruit flies) that will form on a given segment.
However, the statements 'All triploblastic animals possess a coelom' and 'In both protostomes and deuterostomes, the blastopore develops into the mouth' are not correct. While it's true that triploblasts may develop an internal body cavity called a coelom, there are also acoelomates, which are triploblastic animals without a coelom. As for the blastopore, in protostomes, it develops into the mouth, whereas in deuterostomes, it becomes the anus.