Differentiate mitosis from meiosis, understand cell growth limits, and grasp the unifying principles of the Cell Theory.
Historical milestones of the cell theory.
All living organisms are fundamentally built from cells. In 1838, German botanist Matthias Schleiden reported that all plants are made of cells. Just a year later, in 1839, zoologist Theodor Schwann discovered that all animals are also made up of cells.
Differences between growth/repair division and reproductive division.
When you get a small cut on your skin, it heals after a few days. This happens because cells in our body can grow and divide to replace the old, dead, or damaged cells. This process by which new cells are formed from pre-existing ones is called cell division.
Side by side visual of cell division.
Mitosis creates two identical cells, while meiosis is a two-step process creating four cells with half the chromosomes.
Contact inhibition and Programmed Cell Death (PCD).
Cells have a definite lifespan and grow in a controlled way. Animal cells stop dividing when they touch neighbors, a process called contact inhibition. When cells lose this control, they divide endlessly and form tumors (cancer). On the other hand, Programmed Cell Death (PCD) is a healthy, genetically regulated process—like removing the webbing between fingers in a developing embryo.