Patho Essay

     More than one celled organisms grow by way of mitosis and the cytoplasmic division of body cells. On the other hand, meiosis occurs only in germ cells, which are put aside for the formation of gametes (sperm and egg). Reproduction by meiosis allows for species survival and it increases genetic variability.

Mitosis and meiosis are similar in several ways and different in others. The similarities include that both processes involve IPMAT. IPMAT is interphase, prophase, metaphase, anaphase and telophase. The parent cells are diploid. They both end with cytokinesis. In Metaphase and Metaphase II, the sister chromatids line up along the center. Then in Anaphase and Anaphase II, these chromatids are split and pulled towards the centrosomes. The differences are that mitosis consists of 1 division while meiosis consists of 2. Four genetically different, haploid sex cells are the products of meiosis and 2 identical, diploid somatic cells from mitosis. Mitosis occurs in all organisms except viruses and meiosis only occurs in plants, animals, and fungi.

b) How do the products of meiosis compare to the original cell? Think about chromosome number. (1 point)

Mitosis is one of two main methods of cell replication, the other being meiosis. It is “the simple duplication of a cell and all of its parts” resulting from the splitting of a cell. The ‘parent’ or original cell splits, duplicating its DNA (packaged in chromosomes) producing two ‘daughter’ or new cells with the same genetic code. There are four stages of mitosis; Prophase, Metaphase, Anaphase and Telophase. Interphase is not an official phase of mitosis as the cell is at ‘rest’ and not being divided during this phase. It is often called one of the phases of mitosis as it is one of the stages in the life cycle of a cell; however it is not a phase of mitosis due to the fact that no division takes place.

This study was performed in order to gain more knowledge on mitosis and meiosis. This lab was done by observing mitosis in plant and animal cells, comparing the relative lengths of the stages of mitosis in onion root tip cells, stimulating the stages of meiosis, observing evidence of crossing-over in meiosis using Sordaria fimicola, and estimating the distance of a gene locus from its centromere. Mitosis is the scientific term for nuclear cell division, where the nucleus of the cell divides, resulting in two sets of identical chromosomes. Mitosis is accompanied by cytokinesis in which the end result is two completely separate cells called daughter cells. There are four phases of mitosis: prophase, metaphase, anaphase and

2.Meiosis - the division of a cell 's nucleus, ultimately resulting in four daughter nuclei, each with half as many chromosomes as the original nucleus. includes two nuclear divisions meiosis I and meiosis II. Chromosome number is reduced from haploid to diploid.

Mitosis creates identical cells to replace old or dying cell tissue while Meiosis occurs in the sexual reproduction organs and creates genetically different cells.

(O’Connor, Clare) In Metaphase, the centromeres of the chromosomes line up in the center of the spindle fibers to get ready for the next phase to follow. In anaphase the sister chromatids begin to separate and microtubules shorten. In the second part of anaphase the microtubules move past each other and spindle fibers separate. (O’Connor, Clare). The last stage of mitosis is divided between telophase and cytokinesis. The chromosomes condense, nucleus reforms, and in cytokinesis the cytoplasm separates. (O’Connor, Clare) Once the entire process has been complete, two identical daughter cells are formed.

Meiosis 2 is similar to mitosis, however, at the end of meiosis II, four haploid cells called gametes have been formed, each with no duplicate chromosomes. The chromatids of each chromosome are not identical

Meiosis is a two part cell division (meiosis 1 and meiosis 2) process that produces four daughter cells, each having half the number of chromosomes of the parent cell—such as the product of

Centriole replication also begins in G1 and normally continues until G2.When the activities of G1 have been accomplished the cell begins the S phase. In this phase there is DNA replication and the synthesis of proteins and histones in the nucleus. The aim of DNA replication in cells is to prepare the cells to undergo mitosis, copying the genetic information in the nucleus . A single chromosome copy is given to each of the daughter cells.Once DNA replication is completed there is a concise G2 phase dedicated to last-minute protein synthesis and completion of centriole replication. The cell will then enter the M phase (prophase, metaphase, anaphase and telophase) and the beginning of mitosis.During prophase the DNA changes to form chromosomes while for mitotic spindle made of proteins called micro-tubules begins to form and attaches to the kinetochores on each chromosome. -In metaphase the chromosomes are moved to the centre plate of the cell by the spindle microtubules.In anaphase the micro-tubules attached to the kinetochores of each chromosome shorten pulling the chromatids of each chromosome to polar ends of the cell while the unattached micro-tubules stretch the cell.

Meiosis is the second important kind of nuclear division. It resembles mitosis in many ways but the consequences of meiotic divisions are very different from those of mitotic divisions. While mitotic division may occur in almost any living cell of an organism, meiosis occurs only in special cells. In animals, meiosis is restricted to cells that form gametes (eggs and sperm). Each species has a characteristic number of chromosomes per somatic cell. Fruit flies have 8; normal humans have 46. They exist as homologous pairs (partners) that are similar in size and shape and carry the same kinds of genes. Thus humans have 23 homologous pairs. The full complement of 46 chromosomes is referred to as the

Mitosis and meiosis are both forms of the nucleus in eukaryotic cells and share some similarities, but also exhibit distinct differences that lead to very different outcomes (UK essays 2013; widmaier et al, 2014; Toole, 2015; Khan, 2016). Mitosis is a cell division that produces two daughter cells receiving a copy of every chromosome with the same genetic component as the parent cell, while meiosis is a cell division that produces haploid sex cells or gametes which contain a single copy of each chromosome (widmaier et al, 2014; Diffen, 2016; Toole 2016; Encyclopaedia Britannica). The purpose of mitosis is cell regeneration, growth, and asexual reproduction, while the purpose of meiosis is the production of gametes for sexual reproduction (UK essays 2013; Vancouver community college, 2011).

Eukaryotes can reproduce in two ways, via mitosis and meiosis. Mitosis is a process of cell division where a single round of replication is followed by separation of sister chromatids to form 2 daughter cells that are genetically identical to the parent cell. On the other hand, during meiosis, a single round of DNA replication is precedes two rounds of cell divisions leading to the formation of haploid gamete from a diploid parent (Figure 1).

Meiosis: Meiosis is a sexual cell reproduction process whereby a single cell divides its homologous chromosomes equally to form two haploid cells with half the chromosomes of the parent cell.