B.6B_CellSpecialization_Approaching – 02

A honey bee colony is a large, well-organized social community. It is made of thousands of bees working together towards a common goal. That goal is to survive and maintain the colony. There are three types of honey bees of different sizes and shapes. The bee types have different body structures that make them perfect for special roles in the colony. The bees communicate with each other as they perform their individual tasks to maintain the colony.

A multicellular organism can be described as a large, organized community of many cells. The cells work together towards a common goal, just like the honey bees in the colony. The goal is to keep the organism alive in a steady state. The organism is composed of cells of different sizes and shapes. The cells also have structures that allow them to carry out specific functions. The cells communicate and work together to maintain the organism.

A honey bee colony is successful because the diverse members have special skills. They divide the work needed to keep up the colony. A multicellular organism works in the same way. Different types of cells divide up the different tasks that keep the organism alive. Cell differentiation is a process in which similar cells are modified to become different from each other. During differentiation, the cells develop specialized structures to perform different functions. Cells use chemical signals to control and coordinate the process.

A multicellular organism can be made of trillions of cells, but it begins as one fertilized egg cell. How can one cell become an organism made up of so many cells? The simple answer is through mitosis, or cell division. Cell division allows the genome, or complete set of genetic instructions, to be passed on from the fertilized egg to all future cells.

Cells do not need to follow the instructions of the entire genome. A cell only needs to turn on the genes for its own needs. Think of this as having a recipe book with hundreds of recipes, but you only need to make brownies. You will only read and follow the recipe for brownies.

Cell specialization is possible because there are chemicals inside cells that only turn certain genes on and off. Genes that are turned on in heart muscle cells are different than the genes that are turned on in brain cells. The genes that are turned on instruct the cell to build the proteins that the cell needs.