The Process Of Meiosis And Mitosis

     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.

Our hypothesis that if meiosis is present the new formed asci will have different colors was supported by the outcome of our observations. The fact that different sequences of 2’s emerged from the first pattern of 4’s is prove that crossing over took place.

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

These bivalents line up along the equator during metaphase I, the arrangement of the bivalent is completely random and relative to the orientation of the other bivalents, this is known as the independent assortment of chromosomes. This is followed by anaphase I where the homologous chromosomes separate and move to the opposite poles of the cell. At telophase I the cell divides into two, each cell contains one chromosome from each homologous pair. The second stage of meiosis is similar to mitosis.

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)

Refer to the data on the corn kernel color frequency from Part III of the lab. (Remember there were four possible types for this part of the lab.)

A) Meiosis consists of two cell divisions and is broken up into Meiosis I and Meiosis II. At the beginning of the Cell Cycle, in this case there are four chromatids each from the homologous pairs being A, a, B, b. This is the Diploid number (4) meaning it is 2 times the haploid number that will be seen at the end of meiosis II. During the S phase of interphase, the chromatids replicate and reach the end of G2 phase. Now starting meiosis, during the first stage of prophase I the chromosomes condense and pair up through synapsis with their sister chromatids creating AA, aa, BB, bb. After they pair up they go through a process called crossing over, where the homologous chromosomes share a piece of their genetic material with each other. Crossing over allows for the genetic diversity of chromosomes. Now there are four homologous chromosomes Aa, Aa, Bb, Bb, each containing heterozygous alleles because the sister chromatids exchanged genetic information with their homologous pair. During late prophase I, spindle fibers being to form where they will later attach to a homologous chromosomes centromere. The next stage is Metaphase I. During metaphase I, the homologous pairs line up at the metaphase plate, also known to be the center of the cell. The homologous pairs form a tetrad which is considered a group of four homologous chromosomes. These homologous chromosomes orient themselves randomly, which is know as the process of independent

The wild type (WT) and most common color is black, while the mutant type (T) is a lighter tan spore. Each spore must be carefully analyzed along a chain of eight to accurately determine if cross-over played a role in the creation of the ascus. Three different forms of ascus are possible through sexual reproduction of separate hyphae. The different forms are caused by chromosomal cross-over when homologous pairs attach during Prophase I of meiosis. An ascus showing a 4:4 ration of WT to T spores represents an ascus that did not undergo any cross-over. There are two different patterns of cross-over found in Sordaria with the ratios of 2:2:2:2 and 2:4:2 (WT to T spores or vice versa). The different ratios are determined by which sister chromatid that genetic information was crossed over, the ends of the chromosomes being the most

17) The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called

[A labelled diagram of the end of the Prophase stage of a cell here would be

Response Feedback: Meiosis occurs only in replicating gametes or reproducing cells. In phase one, the number of chromosomes is reduced by half but the chromatid pairs remain together. In phase two, the chromatids split apart forming four daughter cells. Non-germ cells such as red blood cells or skin cells undergo mitosis.For more information on this topic, consult:Carol Mattson Porth and Glen Matfin, Pathophysiology, 8th Edition,

Meiosis is really important because it forms the correct haploid number of chromosomes. Since meiosis forms the

Abstract A practical was conducted to observe the various stages of mitosis in the root tips of garlic. Mitosis is the process by which a parent cell divides to give two identical daughter nuclei. The main objectives were to achieve a better understanding of how to use a microscope and to help understand previous studies carried out on mitosis. It was not possible to see all the stages of mitosis under the microscope except for anaphase and metaphase.

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.