sentences: a cell nucleus is a kind of organelle & the cell nucleus controls many of the functions of the cell ->  the cell nucleus is a kind of organelle that controls many of the functions of the cell  the cell nucleus is a kind of organelle that controls many of the functions of the cell & special molecules carry messages from the cell membrane to the cell nucleus ->  special molecules carry messages from the rest of the cell to the organelle that controls the cell  an animal 's brain controls that animal & the endocrine system carries messages from the body to the brain ->  the endocrine system carries messages from the body to the organ that controls the body  the endocrine system carries messages from the body to the organ that controls the body & the body is a part of an organism ->  the endocrine system carries messages from a part of an organism to the organ that controls that part of the organism  special molecules carry messages from the rest of the cell to the organelle that controls the cell & the endocrine system carries messages from a part of an organism to the organ that controls that part of the organism ->  special molecules in cells and the endocrine system both carry messages through parts of an organism to the structure that controls that part of the organism  special molecules in cells and the endocrine system both carry messages through parts of an organism to the structure that controls that part of the organism & if two things perform the same function then those two things are similar -> the endocrine system is similar to special molecules in the cells