These bases are, C G T A each base has a complimentary base e.g. C pairs with G and T pairs with A, these base pairs join in the centre of the two strands by hydrogen bonding. DNA is split into triplet codes of 3 bases, chromosomes which are long strands of DNA highly coiled which contain thousands of genes, these appear in sex cells and before a cell replicates. For DNA to be in every cell of the body it has to be replicated as the parents sex cells cannot hold all the DNA for every cell in the organism, but the parents sex cells do hold all the information for every cell in the offspring. DNA replication takes place in every nucleus in several stages.
Chai Hao Wei (17) 311 Biology Chapter 18: Cell Division Growth: permanent increase in size accompanied by cell division and differentiation Mitosis: Cell division during growth * Growth in plants restricted to growing points: shoot and root tips A nuclear division such that the daughter nuclei produced contain the same number of chromosomes as the parent nucleus * Non-dividing stage of a cell (still absorb nutrients and build protoplasm) * Chromosomes appear as long thin threads called chromatin which cannot be distinguished individually * Centrioles in animal cells divide and chromatin threads replicate Interphase nuclear envelope centrioles chromatin cytoplasm Zygote cells need to be genetically stable for the embryo to develop normally. Replication of Chromatin Threads 1. Two identical chromatin threads produced coil and shorten to become chromosomes 2. Each chromosome consists of two identical DNA molecules called sister chromatids. 3.
Simply stated, Mitosis divides the nucleus of a cell to produce these two daughter cells and consists of five stages. The stages in an animal cell include Prophase- chromatin is condensing and the mitotic spindle begins to form, but the nucleus is still intact, Metaphase- spindle is complete and the chromosomes are all aligned at the metaphase plate, Anaphase- the chromatids of each chromosome have separated and the daughter chromosomes are moving back to the poles of the cell, Telophase- daughter nuclei are forming and Cytokinesis has begun. In plants, this process is quite the same except for Cytokinesis. Instead, while in Telophase, vesicles from the Golgi apparatus move along microtubules to the middle of the cell, producing a cell plate. Cell wall materials are carried in the vesicles that make up the cell plate and then are released, and actually form two cell walls.
The joining of two sex cells will produce a cell with the full number of chromosomes. That cell will then continue to divide in order to create a new organism. Meiosis is divided up into several stages, Meiosis I and Meiosis II. They are very to regular mitosis, but four cells are produced instead of the two by normal cell division. In Meiosis I, the homologous pairs in a diploid cell separate to produce two haploid cells.
In the cells of these organisms, the DNA is twisted around bead-like proteins called histones. The histones are also coiled tightly to form chromosomes, which are located in the nucleus of the cell. When a cell reproduces, the chromosomes (DNA) get copied and distributed to each offspring, or daughter, cell. Non-sex cells have two copies of each chromosome that get copied and each daughter cell receives two copies (mitosis). During meiosis, precursor cells have two copies of each chromosome that gets copied and distributed equally to four sex cells.
Still, scientists have made a lot of progress in understanding how certain changes in DNA can cause normal lymphocytes to become lymphoma cells. Normal human cells grow and function mainly based on the information contained in each cell’s chromosomes. Human DNA is packaged in 23 pairs of chromosomes, which are long molecules of DNA in each cell. DNA is the chemical that makes up our genes – the instructions for how our cells function. Some genes contain instructions for controlling when cells grow and divide.
What is Mitosis? Mitosis produces two daughter cells that are identical to the parent cell. If the parent cell is haploid (N), then the daughter cells will be haploid. If the parent cell is diploid, the daughter cells will also be diploid. N → N 2N → 2N This type of cell division allows multicellular organisms to grow and repair damaged tissue.
GENETICS-1 1) Complex organisms produce sex cells that unite during fertilization, forming a single cell known as a) an embryo c) a gonad b) a gamete d) a zygote 2) A cell with a diploid chromosome number of 12 divided two times, producing four cells with six chromosomes each. The process that produced these four cells was most likely a) internal fertilization b) external fertilization c) mitotic cell division d) meiotic cell division 3) Which diagram represents a pair of homologous chromosomes? 4) In minks, the gene for brown fur (B) is dominant over the gene for silver fur (b). Which set of genotypes represents a cross that could produce offspring with silver fur from parents that both have brown fur? a) Bb x Bb c) BB x BB b) BB x bb d) Bb x bb 5) When a certain pure strain of fruit fly is cultured at a temperature of 16˚C, all of the flies will develop straight wings.
Meiosis is the process, it also carries DNA in the chromosomes, which asci have. Section D of this lab was to find the production of MI asci and MII asci, results show that there is a higher amount of MII then there is of MI, in a single slide of perithecia. Introduction There are two types of cell division, mitosis and meiosis. Mitosis is usually used for the growth and replacement of cells, while meiosis produces the spores used in the reproduction. In the beginning of this lab it covered mitosis, the process by which a cell divides into two separate cells, called the daughter cells.
Each one of us have our own special coding. From the point of conception we begin to form from the very cells and genes of our parents. A DNA sequence of this coding is passed on to us in the form of chromosomes, which are found in cells. These cells will release protein as directed by the DNA of the attached chromosomes. “Every human cell contains 46 chromosomes, arranged as 23 pairs (called autosomes), with one member of each pair inherited from each parent at the time of conception” (Kidshealth.org, n.d. updated) This cellular system has come to be called a genome, which contains our complete set of DNA.-our personal inheritance.
1. The definition of Mitosis: Mitosis is the process of which a nucleus divides into nuclei containing the same number of chromosomes. During mitosis the cell duplicates its chromosomes and splits them between two new cells in one division. 2. An explanation as to why the process of mitosis is important to a living organism.
Hans Wun Alice Contreras English 1A 11/12/09 Concept Essay A single microscopic organism among millions is engorged with nutrients as it prepares to replicate its DNA in the cell nucleus. After replication, two analogous sets of chromosomes are present, bound together at one position by chemicals, almost like a pair of chopsticks shaped like an “X” tied by a rubber band at the cross. Upon completion of the cell cycle, this parent cell will divide into two diploid daughter cells, each having the same number of chromosomes and amount of DNA. This long and complex process serves as the basis for cell reproduction, allowing all types of cells—blood, hair, and skin, to renew themselves. By this same form of cell division a cell can uncontrollably replicate and form a tumor.
Biology Lab Report The most important part of the mitosis cycle, Interphase, and the following decrease of number of cells throughout each stage. Alina Bektemirova October 31 Introduction: Mitosis is a type of cell division in which a daughter cell receives the same number of chromosomes as the parent cell. Within the region of cell division, you should be able to locate many stages of mitosis taking place. Cells come into existence through the division of their parent cells and most of the cells divide in turn producing daughter cells. Usually, this occurs during mitosis, when genetic material is duplicated, and one copy is passed onto each daughter cell.
Mitosis produces two daughter cells that are identical to the parent cell. Meiosis produces daughter cells that have one half the number of chromosomes as the parent cell (Michael J. Gregory, 2006). Meiosis is necessary in sexually-reproducing organisms because the fusion of two gametes (fertilization) doubles the number of chromosomes. The purpose of mitosis is for single-celled organisms to divide to reproduce. Cell division in multicellular organisms enables the organism to grow larger while the cells remain small.
The cell-division cycle is a vital process by which a single-celled fertilized egg develops into a mature organism, as well as the process by which hair, skin, blood cells, and some internal organs are renewed.  Figure 1: The cell cycle http://adasilva.glogster.com/chapter-10-bio/ Mitosis is the process that facilitates the equal partitioning of replicated chromosomes into two identical groups. Before partitioning can occur, the chromosomes must become aligned so that the separation process can occur in an orderly fashion. The alignment of replicated chromosomes and their separation into two groups is a process that can be observed in virtually all eukaryotic cells.  Both the alignment and separation processes are the consequence of the chromosomes interacting with filamentous proteinaceous structures, known as microtubules.
For females, the gametes are produced in the ovaries. For the offspring to look like the parents, the offspring’s first cell must have all the genome of its two parents. A genome is an organism’s complete set of genes. The body cells, also called somatic cells, make-up most of the body’s tissues and organs. The DNA in these cells doesn’t get passed down into the offspring.
What is gene therapy? Carried on chromosomes in the nuclei of all somatic cells, genes are the basic physical and functional units of heredity. Passed from parent to child, they contain instructions for making proteins. If genes are altered, they may not produce the right proteins or produce them correctly, and a child can develop a genetic disorder such as cystic fibrosis or haemophilia. Gene therapy is an experimental technique for correcting defective genes responsible for disease development.
This is how multi-cellular organisms grow larger and repair damage. Meiosis creates haploid gametes. These are the cells used in sexual reproduction such as eggs in females and sperm in males. These cells only have half the genetic makeup of the parent cell. Mitosis can occur in either haploid or diploid cells, whereas meiosis occurs only in cells with the diploid number of chromosomes.
The process involves meiosis – having the exact number of chromosomes from both parents (23 from each). It also includes fertilization which fuses two of the gametes and the restoration of the original number. When meiosis occurs the chromosomes of each pair crosses over to create homologous pairs. Most animals (including humans) and plants reproduce sexually. Sexually reproducing organisms have two sets of genes for every trait (called alleles).