Why We Study the Cell and Its Components - Biology

Biology is the scientific study of life. In order to study life we need to understand cell function. The cell is the beginning of all living things. The more knowledge we obtain about the different types of cells, the more we learn about how life begins. A human body can contain about 10 trillion cells. That is why cells are often called the building block of life. A cell has two categories prokaryotes and eukaryotes.

The two basic categories of cells are prokaryotes and eukaryotes. Prokaryotic is defined as "before the nucleus" with means it does not have an internal membrane. In prokaryotic cells the function of a nucleus is not need because it is smaller in size and all materials in the cell are closer together. Prokaryotic cells reproduce through a process called binary fission. The two domain organisms that are prokaryotic are bacteria and Achaea.

Eukaryotic cells first appeared around a little more than town billion years ago. The organelles found in eukaryotic cells are mini organs specialized for the tasks needed for the cells to function and survive. The most obvious organelle in any eukaryotic cell is the nucleus. The nucleus function in a eukaryotic is to sequester the DNA and separate into small chambers. The DNA in the eukaryotic are organized into chromosomes. The nucleus is surrounded by a membrane called the nuclear envelope that controls the flow of molecules between the nucleus and the rest of the cell.

Having the ability to examine cells more closely has shown that whether it is a prokaryotic or eukaryotic cell, both types contain many of the same components. The most common components of both cell types are a cell wall, plasma membrane, DNA, ribosomes, RNA, and it also has a similar basic metabolism like photosynthesis and reproduction.

It was discovered by Rudolf Virchow that " cells come from other cells." A cell goes through a cycle in order to create a new cell. Cycle one is known as G1, this is the first growth phase. The second phase is known as S, and that is when the cell is prepared to have the DNA copied. The third phase is known as G2, which is the second growth of the cell. The last cycle is known as M, this phase is when the cell is divided into two identical nuclei. During the M phase is the mitosis comes in.

Mitosis is the equal division of cells. This has four stages Prophase, metaphase, anaphase, and Telophase. The first stage is when the cromosomes are visible from a microscope. The second stage the chromosomes align with cell in order to divide up equally and once aligned the cell begins to pull apart. The third stage is when the cell is separting. A polar region develops. The sets of chromosomes are pulled in either direction toward each pole. The final stage is when the chromosomes begin to uncoil and the nuclear starts to reform.