Dna Replication And The Cell Cycle

Mitosis: This is the process by which a cell duplicates the chromosomes in its cell nucleus in order to generate two identical daughter nuclei.

Mitosis happens in the reproduction of unicellular organisms and in the addition of cells to a tissue or organ in a multicellular organism.

This particular type of cell division results in the production of four daughter cells per parent cell with only half the number of chromosomes of the parent cell in each daughter cell. The process of meiosis can be separated into two cycles, the 1st division and the 2nd division. The first division consists of 4 phases. Prophase, Metaphase, Anaphase and Telophase. The Second division consists of prophase II, Metaphase II, Anaphase II and Telophase II. Interphase occurs at the beginning of each phase and Cytokinesis occurs at the end of each phase. Meiosis is used for the production of gametes, or sex cells, in sexually reproducing organisms. These daughter cells have only half the number of chromosomes of a normal body cell. This is important because when two gametes come together, the number of chromosomes in the zygote

First, the nucleus (containing the DNA) is removed and the rest of the cell is thrown out while the nucleus of an egg cell is also removed. Next, the nucleus of the somatic cell is inserted into the egg cells nucleus place. After the insertion, the host cell reprograms the somatic cell nucleus. The egg will begin to divide. Lastly, after many mitotic divisions the single cell can form a blastocyst with closely identical DNA to the original organism (SCNT).

How DNA replicates is quite a simple process. First, a DNA molecule is "unzipped". In other words, it splits into two strands of DNA at one end of the DNA molecule. This separation will cause a formation of a replication fork.

3) Copy: DNA Polymerase joins individual nucleotides with their complementary counterparts to form a new strand of DNA. Replication runs in the 5’ to 3’ direction.

DNA replication is necessary for organisms to stay alive and reproduce. When cells replicate, the DNA must also be copied so the daughter cells contain the genetic information necessary to perform key chemical reactions. Cells have machinery that read the information in DNA and use these instructions to make proteins. To make proteins, the DNA must first unwind in order to be "read." This small section is then replicated to form a single stranded RNA strand. The RNA strand then forms what is called messenger RNA or simply mRNA. The mRNA is used to make the proteins the cell needs.

Strands of the DNA are composed of a sugar and phosphate, portions of the nucleotides while the middle parts of the DNA are made up of nitrogenous bases. The hydrogen bonds between phosphates cause the DNA strand to twist. The nitrogenous bases point inward on the ladder and form pairs with bases on the other side, like rungs. The nitrogenous bases on the two strands of DNA pair up, purine with pyrimidine (adenine with thymine and guanine with cytosine) and are held together by hydrogen bonds. DNA has a spiral staircase-like structure. The steps are formed by the nitrogen bases of the nucleotides where adenine pairs with thymine and cytosine with

“We are examining mitosis, microtubules, and the idea that all cells need to replicate. We make the replication process easier to understand by starting at the smaller part of the human, the cell. Additionally, the concept that DNA replicates into identical copies of itself is made simpler by first looking at plants and then later to animals.”

The cell cycle refers to sequence of events that takes place in a cell leading to its division and duplication (replication). This process is important to genetics because through the cell cycle genetics information for all sorts are passed from parents to daughter cells. (Griffiths. A et al)

There are several enzymes that take part in the DNA replication process. They are Helicase, DNA Polymerase III and Primase. In helicase, this enzyme has several functions in helping make the replication fork so different functions are allowed to occur (Wolfe, 2016). Helicase unravels the double DNA helix to a single stranded template of Adenine, Thymine, Cytosine and Guanine allowing these to be copied (Wolfe, 2016). DNA helicase during single strand separation from the helix also forms the replication fork (Wolfe, 2016). This in turns during the single strand of the nucleotides A, T, C, G still have match together for correct sequence

During this lab the Drosophila cells had to go through certain processes so we could insert the double stranded RNA. The first process is replication. Replication is a semiconservative process in which two strands of DNA are created from one double strand of DNA. The total production is four single strands of DNA, each strand made from one old and one newly made single strand. Replication first starts with a cluster of proteins called a protein complex. When a protein complex binds to a section of DNA with adenine and thymine repeats, called regions of replication, it creates a ‘bubble’ between the DNA. With a small opening in the DNA an enzyme called helicase comes in and makes the bubble larger. In order to keep the DNA from joining back together a protein binds to the open DNA. Primase, another enzyme, lays down little strands of RNA for an enzyme called DNA polymerase III to bind to so it can add new complementary nucleotides to create a new segment of single stranded DNA. DNA Polymerase III can only work

The basic building block of all living things, cells hold within them the genetic blueprint that drives all living things: DNA. DNA is made up genes, which are made up of a series of nucleotides: Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). Through complementary base pairing, these nucleotides hydrogen bond with each other to create an intertwined double helix. The organization of these nucleotides determines the genetic code of the organism. Since all cells are made up of DNA, DNA replicates itself prior to starting both mitosis and meiosis, processes required for cell proliferation. In these processes, although errors

DNA replication is described as semi-conservative. It is semi-conservative because the replication of one helix results in two daughter helices each of which contains one of the original parental helical strands. Furthermore, it is semi-conservative because the two new daughter DNA molecules are “half old” and “half new”; this means that half the original DNA molecule is saved, or conserved in the daughter DNA molecules.

The process of DNA replication plays a crucial role in providing genetic continuity from one generation to the next. Knowledge of the structure of DNA began with the discovery of nucleic acids in 1869. In 1952, an accurate model of the DNA molecule was presented, thanks to the work of Rosalind Franklin, James Watson, and Francis Crick. To reproduce, a cell must copy and transmit its genetic information (DNA) to all of its progeny. To do so, DNA replicates following the process of semi-conservative replication. Two strands of DNA are obtained from one, having produced two daughter molecules that are identical to one another and to the parent molecule. This essay reviews the three stages