Answer:
The cell membrane, or in plant cells, the cell wall
Explanation:
In a plant cell the cell wall helps maintain structure, and in animal cells, the cell membrane regulates what goes in and out of the cell and acts as a structure
Scientists most often produce new genetic variations of organisms by causing mutations with radiation or chemicals and then selectively breeding in order to emphasize the desired traits in the new variations. The Dachshund is an example of this. By breeding two dogs with a similar mutation that caused student legs and elongated backs breeders were able to create a new variation not found in nature.
A because if you are going down deeper into the ocean, you are going farther away from the sun so it will become colder.