What can you do with a cell? We don't typically think a lot about our cells. The adult human has approximately 37.2 trillion cells, all in communication with one another, like a big beehive. We are a huge collection of cells. These cells each have jobs too. We have hair cells and skin cells and heart cells and brain cells. Our cells work together so that we as individual organisms can survive. Ourselves talk to one another in assignment we need more cells. For example, have you noticed that your hair or that your fingernails are growing? This is because cells are dividing. And cells also talk to each other to know when cells need to be taken away or removed. Removal of cells happens through two processes necrosis, which is when cells dies because you tripped, fell and accidentally killed a bunch of them, or apoptosis, which is when it's time to get rid of cells, either because they've gone rogue or become cancerous or because you don't need them anymore. Like we're a fetus developing we have webbing in between our fingers and then apoptosis happens to get rid of that webbing so that we don't have it when we're born. This video is in honor of cells. We have trillions of them, but what can you do with just one? Well, for example, you can make another human. I was watching my son run around the other night after dinner. And I commented to my husband about wow, look what you can do with a single cell. My son came into being because my husband donated one cell because I donated one cell. My husband donated a sperm and I donated an egg. These special cells also called gametes are unique and that they can combine together and form a new individual. Once the cells combined and form that new cell, the new cell is called a zygote. The zygote is an entirely new being that is of part me and a part my husband. If you're confused by this math isn't one plus one two came in so special because they have half as much DNA as a regular cell. So if you think about this in terms of money each gamete is a 50 cent piece to 50 cent pieces add up to $1. Same idea with ourselves, two gametes adds up, together to get organism, the zygote divides to form new cells. These cells differentiate, this is the process when cells get assigned their job. So for example, to be a brain cell or a hair cell. And eventually you get a fully formed human. We will come back to human growth and development more on course 4. So what else can you do with a cell? You can get screened for cancer. Remember when I said that cells have jobs and then all of our cells are in contact with one another. Sometimes a cell stops doing their job or they stop listening, said otherwise, they stop responding to cellular cues. If a cell goes rogue or becomes cancerous, oftentimes the bundle will try to get rid of rogue cells through apoptosis or programmed cell death. But sometimes that doesn't work either, and rogue cells begin to grow out of control and spread. Cells growing out of control can lead to a massive rogue cells also called a tumour, and they're spread throughout the body, which is called metastasis can eventually lead to death. Cancer starts with just a single rogue cell. We'll come back to how and why cells become cancerous later in this module. So in addition to getting cancer because of rogue cells, we can also prevent cancer by looking at single cells too. Had a mole removed and biopsy. Maybe you've had a pap smear before, pap smears or when cells of the cervix are taken off with a small brush and looked at under a microscope. In both of these tests, individual cells are removed and analyzed under a microscope to look for signs of cancer. This could be unstable DNA, for example. And if the cells and that biopsy looks suspicious, the doctor call you to come back and for example, have the margins removed. So maybe you've had a mole cut off before and you get a call and they say you know what, we need to come in and take a little bit more out, the cells didn't look good. So removing the margins is when the surrounding cells are removed to make sure that there's absolutely no rogue cells left. So a single cell abnormality can lead to cancer, or the identification of a single cell abnormality can be used to prevent getting cancer all together. So our last example what you can do with a single cell is you can find out more about who you are biologically. Have you done genetic testing before, either at home or in response to doctor's orders? Looking at ourselves, and specifically, the DNA and ourselves can tell us a lot about who we are, and about our overall health. Each cell in your body contains your entire genome. That's all of your DNA. There's a copy in all of your trillions of cells. And what's really neat about that is that a full copy of your DNA is about six feet or two meters long in a single cell. Wow, that's a lot of information about you and your family too but more on that module four. Genetic testing or DNA sequencing is uncovering what is in your DNA. For example, you can get a genetic test to see if you carry the gene variants associated with developing celiac disease. How do you get tested, you donate a few of your cells. What about your overall health your doctor can order a complete blood counter CBC to see how healthy you are. If you have any underlying infections or if you're anemic or have low iron levels, all of this can be done by looking at the cells in your body. A single cell has all the information about you and cells of a specific type like those in your blood can tell us about our health. So in summary, what can you do with a cell? Well, you can make a whole new human, you can get or prevent cancer, and you can find out a lot more about who you are genetically and about your health. It's pretty neat for something that we're made of, but don't always think about too often.