Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the first of three Science Objects in the Cell Division and Differentiation SciPack. It discusses the basics of cell division, the cell cycle, and how cells continue from one generation to the next.
Cells carry on the many functions needed to sustain life, including cell growth and development. The genetic information encoded in DNA molecules provides instructions for assembling protein molecules, which are both necessary for producing more cells and performing other cellular functions. Before a cell divides, the instructions are duplicated so that each of the two new cells gets all the necessary information for carrying on. Complex interactions among the different kinds of molecules in the cell cause distinct cycles of activities, including cell growth and division. Cell activity can also be affected by molecules from other parts of the organism, or even other organisms. Cells in multi–cellular organisms repeatedly divide to make more cells for growth and repair. Without cell division the surface area to volume ratio that constrains the size of single cells would limit an organism’s growth. Cell division in single–cell organisms makes asexual reproduction possible. Changes in DNA (mutations) occur spontaneously at low rates. Some of these changes make no difference to the organism, whereas others can change cells and organisms. In multi–cellular organisms, uncontrolled cell division, called cancer, can be caused by gene mutation. Exposure of cells to certain chemicals or radiation increases mutations and thus increases the chance of cancer.
Describe the cellular events related to genetic material that must occur for cell division leading to growth or repair in multicellular organisms.
- Interpret the results of experimental variables, both internal and external to the cell, affecting cellular growth and division displayed within an experiment’s graphs or data charts.
- Compare and contrast normal, healthy cell division and cancer.
- Explain at the cellular level how recommendations for cancer prevention (i.e. smoking cessation) might influence and affect incidents of cancer.