D. Certain genes are turned on and others are turned off; this action produces adult cells that are specialized
<span>The correct answer is b. The open ocean. The definition of an island ecosystem does not have anything to do with water, but simply refers to an ecosystem that exists as a microcosm within a far larger, separate ecosystem. The ocean has lots of separate island ecosystems within it, but it itself cannot be referred to as one.</span>
Its quite difficult to understand the question
The answer is Cell Membranes.
Answer:mammals,fish, bacteria
