Can you imaging everyone’s appearance is the combination of all his ancestors but not exactly the same? The video “Life’s Greatest Miracle” tells you why and how did that happen when you are just a single cell at the very beginning. The attractive video brings me to a physiological world. First, I am surprised by the amount of sperms that a man could produce. Thousands of them are made every second, a hundred million in a day, and trillions over a lifetime. This is an amazing ability and opportunity that the nature endows for human beings to have our offspring. Second, I find that it is a way full of obstacles for sperms to reach the eggs.
They have to get through from cervix –– passage way to the uterus, to fallopian tube. For example, the cervix usually shuts, preventing the bacteria and sperm out. The only way is to wait until a tiny channel appears within a few days in a month. After entry, sperms still have a six-inch distance and then break through support cells and a zone. In my opinion, the quality and quantity of sperms are both vital for sperms because only few sperms could survive through these processes, and some of the obstacles could be overcome only under the help of a large number of sperms.
Third, from a single cell, human beings build a body that has 100 trillion cells. We made hundreds of different kinds of tissues and dozens of organs, including a brain that allows us to do remarkable things. Some people think that machines could duplicate brains and human beings could be replaces by clever robots one day. But I think human beings are more than the most complicated machines in the world. Human brains are created in a special chemical way, which could not only manage actions, but also create and discover new things with our intellectual brain.
Personal computers, vehicles, media are the strongest support for the unduplicated brains. Fourth, although the cells have identical genetic information, they don’t look the same and have different functions. Such as the nerve cells, blood cells and white cells. It is because different groups of genes in DNA are turned on, they tell the cells to construct a different-function protein. Like collagen, a fiber that makes up skin and bones, or keratin makes up hair. Before, I always have the wrong idea that there is only one type of protein in our body because the genetic information is the same in each cell.
But the truth is, the varieties of genes are more than I expect. I should learn more about different kinds of protein in our body. Fifth, the pregnant woman Melinda in the video talks about “morning sickness” related to her and her husband. I think it common for expectant mothers to have morning sickness because of a specific kind of hormone rises in their body and their more sensitive feelings to the environment. However, I was surprised when I first knew their male partners might suffer from morning sickness too. My pregnant friend’s husband Lois suffered from a slight morning sickness and bloating.
He thought of eating too much at first, but recognized only after the doctor told him. It may result from the hormonal influences, or because of the excessive stress. In the video, we know that when the chromosomes of sperm and egg approach each other, the cell begins to divide. Gradually creating the building blocks needed to construct an embryo. Similar information is written in the text about how DNA works – the chemical material that chromosomes consist of. A unique feature of DNA is that it can duplicate itself through a process called mitosis.
This special ability permits the one-celled fertilized ovum to develop into a complex human being composed of a great many cells. And you will see that during mitosis, the chromosomes copy themselves. As a result, each new body cell contains the same number of chromosomes and the identical genetic information. (Laura E. Berk, 2012, p. 53) As we know, chromosomes are made up of DNA. Through the process of mitosis, DNA is capable of duplicate itself. This explains how does chromosomes duplicate themselves and why each body cell consists of the same genetic information.
The video also talk about we can sometimes make out the sex around 18 week. But in the early weeks, it’s impossible. By the time most ultrasounds are done, doctors can sometimes make out the sex. But in the early weeks, it’s impossible. It reminds me of what I read on the text: From 9-12 weeks of pregnancy, external genitals are well-formed, and the fetus’s sex is evident. (Laura E. Berk, 2012, p. 97) Nevertheless, in the video, Melinda does not want to know the sex of the baby beforehand. As far as I am concerned, the sex is determined by whether an X-bearing or a Y-bearing sperm fertilizes the ovum.
We may not know until the external genitals are developed. But is it a good idea to know about it? In some culture, people prefer a boy than a girl may try to figure out the sex of the fetus, and decide to persist on having the baby or not. I do not think it is a smart way for people to quit the baby because of sex. And seeing the sex through ultrasound is prohibited in some countries. One of the fun thing in the video is that Melinda has to smell the food first, then decide whether she wants to eat it or not.
It is not surprise that she is hungry because the fetus she’s carrying has only one source for all the raw materials it needs to grow—Melinda’s blood. It is elaborated in the text book by saying: By bringing the mother’s and the embryo’s blood close together, the placenta permits food and oxygen to reach the developing organism and waste products to be carried away. (Laura E. Berk, 2012, p. 98) That means what mother eats has a direct relationship to what fetus receives. It should be appropriate and cannot be either too abundant or too poor. But the most important is that the food has to be nutritional and health to the fetus.
