1. The sizes of their necks vary
Answer:
it depends on changes in gene expression
Oceanic crust is constantly formed at mid-ocean ridges, where tectonic plates are tearing apart from each other. As magma that wells up from these rifts in Earth's surface cools, it becomes young oceanic crust. ... Just as oceanic crust is formed at mid-ocean ridges, it is destroyed in subduction zones.
Answer:
I believe the answer would be 'E. hotspots'.
