Why did you post this again? Because you're lazy and wanted people to not see my post? Once again, ONE QUESTION AT A TIME. We're here to help you with a tough question or work you through it, not do all your homework.
Explanation:
Plant cells have a cell wall, as well as a cell membrane. In plants, the cell wall surrounds the cell membrane. This gives the plant cell its unique rectangular shape. Animal cells simply have a cell membrane, but no cell wall.
Answer:
Please see the attachments
Explanation:
Please see the attachments below structures of the 3 isomers of C8H18 that contain 3 methyl branches on the main chain, 2 of which are on the same carbon.