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Showing posts from March, 2026

Blog 42: How Cells Decide What They Become

Hey everyone! Welcome back to this week’s blog. Over the past few weeks, I’ve been diving into how cells control their identity. I’ve talked about gene regulation, epigenetics, and even how scientists can reprogram cells or convert them into completely different types. But as I was thinking, all of the topics I’ve talked about the last 4 weeks lead to one bigger question: Before we even try to change a cell’s identity . . . how does it get that identity in the first place? How does a single cell know whether to become a neuron, a muscle cell, or part of your skin? That’s what today’s topic is about, and the process is known as cell fate determination. What Is Cell Fate? Cell fate refers to the final identity a cell adopts. Early in development, cells are much more flexible. They have the potential to become many different types of cells. But as development continues, cells gradually become more specialized. At some point, a cell commits. From that point on, it will follow a specific pa...

Blog 41: Cellular Reprogramming

Hey everyone, and welcome back to the blog! I hope you guys have all had a good weekend and can sit back, relax, and enjoy today’s topic as you wrap up. Last week I talked about transdifferentiation. In case you didn’t read, transdifferentiation is the idea that one mature cell type can sometimes be converted directly into another. That concept alone already challenges the traditional view that cells are permanently locked into their identities. But scientists eventually discovered something even more surprising. Instead of converting one cell type directly into another, it’s sometimes possible to reset a mature cell back into a stem-like state.  This process is called cellular reprogramming. What Is Cellular Reprogramming? Cellular reprogramming is the process of taking a fully developed cell and reverting it to a pluripotent state, meaning it can develop into many different cell type s. These cells are thus known as induced pluripotent stem cells, or iPS cells. The key idea is th...

Blog 40: Transdifferentiation

Hey everyone, and welcome to blog number 40! It’s been almost a year since I posted my first blog, and it's crazy to see how far I’ve come. For this week’s blog, I thought about the last two weeks of topics. And after writing about gene regulation and epigenetics, I started thinking about a question that sounds almost impossible at first. If cells can specialize into different types during development, do they remain stuck in that specialization forever?  And, for a long time, scientists thought the answer was yes. Once a cell became a muscle cell, neuron, or skin cell, that identity was considered permanent. But modern biology has revealed something much more interesting. In some cases, cells can change their identity, a process called transdifferentiation. What Is Transdifferentiation? Transdifferentiation occurs when one mature cell type directly converts into another mature cell type. Importantly, the cell does not first return to a stem-cell state. Instead, it switches identit...

Blog 39: Epigenetics

Hey everyone! Welcome back to the blog series. After last week’s blog on gene regulation, I kept thinking about other fundamental science topics I should talk about. And after looking through Google for about 2 hours today, I decided to write and dive deeper into a perspective of the Synthetic Biology world that is frequently mentioned in my AP Bio class: Epigenetics.  So far in this series, we’ve learned that genes can be turned on or off. But, what actually controls whether parts of DNA are even accessible in the first place? This question is an important one to ask because of one important aspect of Biology: just because a gene exists doesn’t mean a cell can easily use it.  What Is Epigenetics? Epigenetics refers to changes in gene expression that don’t involve altering the DNA sequence itself. The DNA code stays the same, but how that code is read can change. If gene regulation is about deciding which genes to activate, epigenetics is about controlling how accessible those...