Each blue circle in the figure below represents a cell in a cell lineage. Draw two modified versions of the cell lineage so that each version produces three cells. Use apoptosis in one of the versions, marking any dead cells with an X.

Verified step by step guidance

1. Start by understanding the concept of a cell lineage, which is a sequence of cells that are derived from a single progenitor cell through cell division.
2. In the first version, draw a simple cell lineage where the initial cell divides twice, resulting in three living cells. This can be achieved by having the first cell divide into two, and then one of those cells divides again to produce a total of three cells.
3. For the second version, incorporate apoptosis, which is a programmed cell death process. Begin with the same initial cell division as in the first version.
4. After the first division, mark one of the resulting cells with an 'X' to indicate that it undergoes apoptosis and dies.
5. Ensure that the remaining living cell divides again to produce two more cells, resulting in a total of three living cells in this version, despite the occurrence of apoptosis.

Key Concepts

Cell Lineage

Cell lineage refers to the developmental history of a cell as it progresses from a single progenitor cell to its final differentiated state. Understanding cell lineage is crucial for tracing how cells divide and differentiate, which helps in visualizing the sequence of cell divisions and the fate of each cell in a lineage diagram.

Apoptosis

Apoptosis is a form of programmed cell death that is essential for maintaining healthy tissue homeostasis and development. It involves a series of biochemical events leading to cell shrinkage, DNA fragmentation, and ultimately cell death, marked by an 'X' in diagrams. Apoptosis is crucial for removing unnecessary or damaged cells during development.

Cell Division

Cell division is the process by which a parent cell divides into two or more daughter cells. It is fundamental for growth, development, and tissue repair. In the context of cell lineage diagrams, understanding cell division helps in predicting the number of cells produced and their arrangement, which is essential for drawing modified versions of the lineage.