Question

The following questions are based on the description below.

A student encounters an animal embryo at the eight-cell stage. The four smaller cells that comprise one hemisphere of the embryo seem to be rotated 45 degrees and lie in the grooves between larger, underlying cells (spiral cleavage).
This embryo may potentially develop into a(n)
A. earthworm
B. sea star
C. turtle
D. fish
E. sea urchin

Answer 1

The embryo with spiral cleavage is likely to develop into an earthworm, as this form of embryonic development characterizes protostomes, to which earthworms belong.

Step-by-step explanation:

The embryo with spiral cleavage described in the question is a characteristic feature of protostomes. Among the options provided, an earthworm is a protostome and therefore is the organism most likely to develop from the embryo observed by the student.

Spiral cleavage is a form of embryonic development found in some invertebrates and is a feature that distinctively separates protostomes from deuterostomes (e.g., sea stars, sea urchins).