DRAW IT 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.

Video transcript

Hello everyone. The next question asks which of the following correctly depicts the cell lineage of a cell that produces three cells. Apoptosis is shown by X. So a cell lineages and we trace the developmental history of a differentiated cell and we go back through the series of cell divisions all the way back to its original precursor cell in the early embryo. So um when we're looking for that we want some a cell original cell that produced three descendant cells. Well we know that when we have cell division we end up with an even number of daughter cells. So one of those cells, if we're getting three descendant cells, one of those cells must have been destroyed by apoptosis, that process of programmed cell death. So when we look at our answer choices, um we're going to have to see a cell lineage that includes an apoptosis event to have ended up with an odd number of descendant cells. So when we look at our answer choices, we see that choice A. And Choice C. Do not have any apoptosis. And indeed, Choice A. Has four descendant cells. So that's not the correct number and Choice C. Has six. So let's look down at Choice B. Choice B does have an apoptosis event here and we see it has three descendant cells. So Choice B is our correct answer. And when we just double check. Looking over at Choice D. There's apoptosis happening but it's showing four descendant cells and an impossible cell division with into three cells here. So Choice D. Is also not correct. So the answer to this problem is Choice B, and we hope to see you in the next video.