8/11/2019 Reaction Paper on Universe

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Mary Pauline S. Sacay

SCIMATB REFLECTION PAPER

Our Secret Universe: The Hidden Life of a Cell

A cell is the basic unit of life. Everything, the condition of ones body down to health, depends

on the cell. Humans may not notice it but cells are in a constant battle against harmful

organisms. Because a lot of things rest on the cell, it has to have protection from foreign bodies

such as viruses. However, viruses also have a way of turning cells strengths into their own

weaknesses. A virus wrecks havoc into the cell by travelling to the cell nucleus, where the

genetic material is located, and altering the genetic program. A cell may have many available

defenses against these viral infections but viruses also have their own evolutionary methods of

avoiding these cell traps; turning what seemed to be a disadvantage to its advantage. Although

viruses may have their own methods, a cell always has a counterattack and a backup plan.

Although these counterattacks may not always guarantee full protection, a defense is better

than having none at all.

Cell Cycle, Mitosis and Meiosis

The life of a cell goes through a process of birth and death, just like all of us. Actually, it is

because of cells that living things experience that process because they are made up of cells.

Cells, however, go through a constant cycle of reproduction to keep them alive. If cells were to

stop reproducing, it would mean big trouble because it entails that they are no longer part of

the living. The cells divide repeatedly to make more cells in order to prevent the cease of their

existence or to replenish lost cells. Cell division can go either through mitosis (sexual

reproduction) or meiosis (asexual reproduction). Mitosis is a process of cell duplication, or

reproduction, during which one cell gives rise to two genetically identical daughter cells and

these two daughter cells will divide into four and so on with the same number of chromosomes

and genetically identical to the parent cell. Mitosis occurs in every organism, even in humans,

because it makes everything (i.e. muscle tissues, skin tissues, etc.) except sex cells (egg cell and

sperm cell). Meiosis, on the other hand, is a type of cellular reproduction in which the number

of chromosomes is reduced by half through the separation of homologous chromosomes,

producing two haploid cells. This means that the daughter cells contain half of the original

number of chromosomes from the parent cell and are not completely genetically identical with

the parent cell. A perfect example would be the egg and sperm cell, which contains only 23

chromosomes that will determine the characteristics of the daughter cell that will be the

product of fertilization between the two.