churn in American English. churnverb [ I/T ] [ I ] The water was churning and the boat was rocking. [ M ] The fish churned up the water when we threw them some food. [ T ] fig. Seeing the car ahead flip over churned his stomach.
The nucleus controls everything that happens in the cell. This means that it controls the chemical reactions that take place in both and animal and plant cells. Some organelles in the cell have their own job like mitochondria control the respiratory (for example).
This is not found in plants. The cell membrane controls exchange of materials such as nutrients and waste between cells and their environment. They have other important functions, for example to enable cells to receive hormones.Cell membrane is not a function of the brain. This is not found in plants.