How Cells Multiply

Sexual Reproduction vs. Asexual Reproduction

Sexual Reproduction and Asexual Reproduction are trying to accomplish the same thing but in different ways, they also have different pros and cons. Sexual Reproduction involves a mother and a father coming together, to have an off spring. Sexual reproduction does not produce an exact replica of either the mother or the father instead, it produces a combination of both. By mixing chromosomes together during meiosis you will get a unique combination of your fathers and mothers genes. This can make you immune to diseases that may have affected your ancestors and cause you to evolve to your climate. In most species that use sexual reproduction the parents are allowed to choose (In most cases) how many offspring they want to have. This is good due to the reason that if you have too many offspring, you may have to compete for food causing the whole family to suffer.

That leads me on to Asexual Reproduction, this is where cells will clone themselves through mitosis. Every time one cells divides it creates another cell that will divide leading to exponential reproduction. This creates competition for food and since the cells cant control them self from cloning over and over the problem for food will keep getting worse and worse. On the flip side rapid reproduction can be a good thing for taking over more land and expanding the “bloodline” witch is the goal for most living organisms. Another downside to Asexual Reproduction is species not evolving. Since these cells are producing exact replicas, it leads to them being susceptible to the same threats as the parent cell. So now with the pros and cons laid out in front of you, witch type of reproduction, in your opinion is better?mitosis

What is Mitosis or Meiosis?

Meiosis is used in the process of sexual reproduction during the production of sperm and eggs. The first step is Interphase, this is when the genetic information is copied within the cell and the cell forms spindle fibers, that later will be used to pull apart the cell. In Prophase1 the duplicated chromosomes will pair up exchanging genetic information causing variation in the offspring. In Metaphase1 the Chromosomes will line up in the middle of the cell and after that Anaphase1 begins. The spindle fibers will pull the pairs of Chromosomes apart to the different poles of the cells. And last in Telophase1 the cell will completely divide and form 2 new nuclei for the 2 new cells. And now we start Meiosis2. Prophase2, there will now be 2 cells thanks to Meiosis1, this means for the rest of Meiosis2 when I refer to something happening to the cell it is happening to both. The first thing that happens is the chromatids pairing up, after that the spindle fibers form in the cell. Now we move on to Metaphase2. This is where the chromosomes line up at the middle of the cell. The spindle fibers are ready to pull them apart. Now in Anaphase2 the sister chromatids are pulled to opposite ends of the cell, the cell starts to pinch the middle causing it to almost break apart.  And finally in Telophase2 the nuclear membrane forms in the two new cells around the new paired chromosomes.

Now we move on to Mitosis, Mitosis is used by single celled organisms to multiply themselves in a quick and timely fashion. It is very similar to Meiosis2 in its process. The first step is Interphase, during this phase the DNA is duplicated and the spindle fibers form. Now comes Prophase, in this phase the chromatids pair up and the spindle fibers form. Notice how there is no number? The reason for this is because of the fact the Mitosis only has one stage rather than two like in Meiosis. Now in Metaphase the chromasomes line up in the middle of the cell while the spindle fibers attach to the sister chromatids. In Anaphase the sister chromatids are pulled to the opposite poles of the cell. And last in Telophase the cell forms two new nuclear membranes and pinches the center of the cell creating a identical new cell.

How do cells grow? This question can be answered if we go all the way back to your conception. You first start as an embryo. Over a period of 8 weeks yours cells will keep dividing via mitosis. After awhile you will go from having a handful of cells (not literally) to having trillions. After that 8 weeks you become a fetus where you will start to grow organs that will allow you to live. You will also form a spinal cord, gain weight, and experience rapid brain development.

 

 

 

 

 

https://www.yourgenome.org/facts/what-is-mitosis

https://www.bbc.co.uk/bitesize/guides/zqv6gdm/revision/5

https://www.britannica.com/science/cell-biology/Cell-division-and-growth

https://www.yourgenome.org/facts/what-is-meiosis

http://cyberbridge.mcb.harvard.edu/mitosis_7.html

https://www.yourgenome.org/facts/what-is-mitosis

Fetal Development Activity from OneNote, 2019 Sem 1 Science 9 Notebook/Cell Reproduction/Fetal Development

https://www.whattoexpect.com/pregnancy/fetal-development/fetal-sex-organs-reproductive-system/

 

Leave a Reply

Your email address will not be published. Required fields are marked *