REFLECTION-CELL DIVISION

Assalamualaikum and a very good morning to Dr. Syakinaz, my beloved lecturer. My name is Raja Nur Arinah and I’m one of your students who is taking Biology 2. Frankly speaking, when I first was given this assignment, writing a reflection of 2500 words about the first chapter, I was pretty worry. Because I don’t know what should I write for 2500 words, despite I don’t know much about mitosis”. But I wake up my mind. Maybe I’m not from biology’s background, but I believe that I can be very good in this subject if I learn about it well. I’m so sorry for this maybe-not-related reflection, but I think it is nice if I start it this way. Before writing this long journey reflection, I would like to say sorry if there’s any grammatical, vocabulary, spelling and others mistakes that I done for my writing since I am not good enough in English.   

All right, before entering this class, yes I’ve heard about ‘mitosis’ word before and I know it is cell cycle which happen in the somatic cell. Others that I do remember about mitosis is that it consists of four stages which is prophase, metaphase, anaphase and telophase. Previously, my teacher at school asked me to remember words “ Pak Mat” to remember the stages of mitosis. Right now, it is not only to remember about the stages. We learn about it more deeply this time. Before we went to the class, we have been asked to made a mind map about mitosis. This is a good method since we can refresh our memory about what we learnt before.

To have a good reflection about mitosis, I think it is much better if I read it  from reference books and internet then I tell what I have understand from it . All human being start from a fertilized egg. Fertilized egg will form from combination of ovum and sperm which eventually came from our mother and father. Start from a single cell (fertilized egg), when time of birth, we will have trillion of cell. So amazing. So, how this happen? How can from a single cell became trillion?

First, let me tell a little bit about what have I understand about the history of the study about reproduction of cell. At first, researchers don’t know how to make cell kept dividing outside the body. These living cells will help them study about various disease and also for the normal life process. George and Margaret Way at John Hopkins University were among the persistent researchers.

Geys siblings had trying to grow cell outside the body for almost 30 years but fail. The cells that kept outside will die after few weeks. Their lab assistant, Mary Kubicek who also involved in this research has also try for thousand of times until when she was about to give up, their wish come true. The last cell prepared by Mary namely Hella cells began to divide again and again. These cell kept dividing that they had to transfer part of it into another culture tubes. Hela cells was named because the cell was taken from a patient name Henrietta Lacks. Henrietta Lacks was dead after two months she had been diagnosed with cancer. But, her cells however kept living in Geys laboratory and had help scientist doing their researches about cells a lot.

Reproduction of cell confirms continuity of life of all organism. The information that encoded in parental DNA must be get by the daughter cell. The daughter cell also should have enough cytoplasm to start up the operation. These are what the challenges of dividing cells faces. A DNA will inform a cell which type of protein it should build. The protein itself can be either structural material or enzyme which also act as catalyst to speed up certain reaction. Therefore, a new cell will function properly if sll the information was not be inherited from the parents.

About the introduction to the cell cycle, it is actually the recurring sequence of events that includes the duplication of a cell's contents and its subsequent division. In single-cell organisms, each round of the cell cycle leads to the production of an entirely new organism. Other organisms require multiple rounds of cell division to create a new individual. In humans and other higher-order animals, cell death and growth are constant processes and the cell cycle is necessary for maintaining appropriate cellular conditions.

The second subtopic that I learn about mitosis is the closer look of mitosis. After learning about this, gratefully I have much better understanding about the process of mitosis. Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets in two nuclei. It then followed by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two cells containing roughly equal shares of these cellular components. Mitosis and cytokinesis together define the mitotic (M) phase of the cell cycle - the division of the mother cell into two daughter cells, genetically identical to each other and to their parent cell. Mitosis invole four important stage which is prophase, metaphase, anaphase and telophase. All of these four processes are important to complete the cell cycle of living organism.

            The third subtopic is the cytoplasmic division mechanism. Cytoplasmic division is a process in which the plasma membrane around the middle of the cell is drawn inwards to form a cleavage furrow. This gradually deepens until the cell is split into two. The mechanism of cytoplasmic division is different. For animal cell, a microfilament ring that is part of the cell cortex contracts and pulls the cell surface inward until the cytoplasm is partitioned, While for plant cells, a band of microtubules and microfilaments formed around the nucleus before the mitosis start. Cell plate then will form. The cell plate will become a cross wall that partitions the cytoplasm.

            The last subtopic that I learn in this chapter of mitosis is when control is lost. This subtopic reveal about what will happen to our body when the division of cell is out of the body mechanism control. That is why the checkpoint in certain part or time of cell division is very important to make the body keep living with the sufficient number of cells which is not less and not more. Mutated checkpoint can cause tumors by disrupting the normal controls. Cancer is also one of the example. Cancer is a multi step process involving altered cells that grow and divide abnormally. Malignant cell is the term literally means growing worse and resisting treatment. It is used as a synonym for cancerous and connotes a harmful condition, that generally is life-threatening.

For my last review, I would like to answer certain questions given by Dr. Syakinaz in order to complete this reflection from the laboratory manual guide. Because, this questions I think, is the best guide to write a good reflection about mitosis. Since the title for this experiment is mitosis which means cell division, yes it is surely connected to me and other’s life. Mitosis is a process where human cell will undergo division continuously but with certain gap. With this cycle our cell will grow and that is why we keep growing. Besides, this process will replace our damaged cell.

Before I learn about this topic, I actually had been taught about mitosis in the class at school before. So I do know a little bit about mitosis. Therefore I already have basic knowledge about this cycle. Before entering the lectures, I  have known that mitosis has 4 stages which are prophase, metaphase, anaphase and telophase.

So, what do I  remember before this learning process of mitosis??. Prophase is the stage where the chromosomes condense and become shorter and the centriole move to opposite site of nuclear envelope. During metaphase, the chromosomes align. While during anaphase, the sister chromatic split to two and move to opposite pole. And the last phase is telophase where a new nuclear envelope forms around each of two clusters of decondensing chromosomes.

The important things when I  learn about this topic can be divided into two which are the way we behave (group experiment) and the process of mitosis itself. For behavior manner these are all about cooperation, self-confident, knowledge, involved actively, obey the rules and creativity. For example to make the model of metaphase (group task), all of us give idea how to make it (cooperation) so that it will be in interesting form and can be easily understand by another group member (creative thinking). Besides, we also have to know the proper way on how to handle the microscope to see clearly the process of cell division (knowledge). During the presentation of our model, we speak out clearly about the task that have been given which is metaphase so that students will completely understand about this phase (self-confidence). During the other group presentation, we have to listen carefully about their explanation and ask them on the spot if we do not understand about it (involved actively). These are all important during learning process and also during the experiment. While for mitosis itself, it is important for human being for replacement damaged cells, cells growth and to repair damaged tissues.

There are so many good things while learning about this topic. For example, the incentives or approaches that are used in this experiment make us more understand about mitosis. At first, it is when in group, we do the model. Now we can imagine that the chromosome structure is like bead on strings. We also coil the bead twice with the tie twist to show that the histone protein (bead) is surrounded by DNA double stranded helix. Creatively, we used socks to represent nuclear envelope and show its disintegration at late prophase (a process before metaphase). So, why this group work is good for me ?. Because it is enjoyable and interesting thus make a good addition for my imagination that will always bear in my mind. Secondly, during the presentation hours, I  have chance to ask any question openly about each stage in mitosis. Sometimes, when someone ask question, I realize that it is a good question since I also do not know about the answer. For example, the question is about where is exactly the position of spindle fiber attached to chromosomes???? Actually the spindle fiber attached to kinetochore a site located at the centromere.

Meanwhile, the bad thing when learning about this topic once again related to the experiment which about handling the microscope. It is because the image of the cell cannot be seen clearly. Of course the stage of division cannot be determined too. Maybe I  do not have enough skill about the way to handle the microscope. Few questions came up to my mind. If the problem is about the skill in handling the microscope, why did another group face the same problem too??? What about the scientist that discover the image of the division? Did they face the same problem too regarding this study?

Nothing gives neither good nor bad thing during the experiment. Each that I  learn, each thing I  do gives their own impact.

Making the model of metaphase, I can easily remember the structure. Why things happen? It is because the cooperation between group members that shares creativity to build the model. The different colors of bead used also can make us easily remember which one is centriole, sister chromatid, centromere and others.

           

The image of the mitosis cannot be seen clearly. This thing did not happen because I have limited knowledge on how to use the microscope.

The other thing could be happen during the experiment is maybe I can see the image of mitosis process clearly under microscope. To make this thing happen, I should learn to increase knowledge how to handle the microscope. I also must use the right magnification power.

In this activity, I can remember the position of the chromosome, centriole and other organelles. Now, I know the movement of organelles more deeply. I also memorize all the stage in the mitosis process. I should inform to myself to remember the important event occur in each stage.

What would I do differently next time we learn?. Since through the method given by the experiment is successful to make me memorize about what happen, each time I learn, I should do the same approaches too. For example when I make notes or mind map for any topics, used different colors, make short notes and interesting diagram or picture. Why? This will be more long lasting memory which will help me a lot in examination and of course for the future.

About the question that if I had to teach someone how to teach I would say that “if you want to educate people, you have to educate yourself first”. Mean that you should have enough knowledge to teach others and if you don’t know much,how can they understand about that topic. I think that colorful key point concept is very good teaching method. Draw a colorful diagram and put the key point about the diagram. When the students know the key points, it depends on the students how to elaborate it. But the point is still there. Other than that, for an educator, if you want to do the presentation by using the slide show, please just don’t read it. The students will get bored easily if you do so.

When I have to teach for the next time, I have to use the different way to conduct the class. Such as, bring the student outside from the class for the best learning environment. I also can use two ways communication during the teaching process.

As a conclusion about my reflection of mitosis, the four haploid cells produced by meiosis must also go through a developmental process to produce egg and sperm in animals, and pollen and ovum in plants. I feel so glad to have a chance to learn about this topic. Hopefully, I can more deeply regarding this topic in my future. Thank you.