Mitochondria Compare And Contrast Essay

Chromosome pairs line up across the equator of the spindle at metaphase I (5). In anaphase I the chromosomes separate and travel to opposite ends of the spindle. The chromosomes migrate to the equators of two new spindles for metaphase 2 (7). Next the chromatids are pulled apart in anaphase 2 to form four clusters of chromosomes in telophase 2. The nuclear envelopes reform around four haploid nuclei that will give rise gamete

A new nuclear envelope forms around the separated sister chromosomes. As mitosis completes, cytokinesis is well underway.

Later on a male and female haploid cell will join to form a diploid cell with the right number of chromosomes.

These centrioles replicate and the chromosomes line along the equator at metaphase II and spilt at the centromeres causing the chromatids to move to opposite sides at anaphase II. At telophase II the cell divides to form four haploid cells, these are not identical to each other because the cells contains chromosomes from two different parent gametes therefore differ genetically. However, during mitotic division the cells produced are genetically identical to each other because they are produced from the same parent cell. The cell begins to replicate during interphase to produce two identical sister chromatids.

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.

1 by crossing over in prophase I , 2 , by indpendenent assortment and three by mutations in S phase

Define the term crossing over. (3 points) During meiosis’ prophase the homologous chromatids exchange segments.

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

Anaphase – the chromosomes are divided into single from pair and the chromosomes move to opposite poles

The structure formed by centrioles made up of microtubules that splits chromosomes during anaphase and pulls them toward opposite poles of the cell. During anaphase, it also helps to elongate the cell, in preparation for telophase.

Page 20: Sam says, “I’m learning so much, could you tell me the next phase”. Yes, replied the fairy, the next is anaphase during this process the spindles grab the center of the chromosomes called the centromere which binds the two chromatids to form a chromosome. The spindles pull at the chromosomes to the opposite

Error 2: In the video, they state that in anaphase “Each CHROMATID transforms into a CHROMOSOME in its own right…And SPINDLE FIBERS drag them to the POLES.” This is incorrect; the chromatids don’t “transform” into chromosomes. They chromatids pair up to make paired

During prophase the spindle fibers are developed and moving towards opposite poles. During metaphase the chromatids aligns at the plane of the cell equator. During anaphase, the paired sister chromatids are separated and each move towards one pole, at this point the cohesin at the centromere are removed. Cohesin, a protein complex, plays an essential role during this process. The core subunits of the cohesin complex are: Smc 1 and 3 (structural maintenance of chromosome (5)), Rad21, and Scc 2-4 (adherin factor) which form a ring-like structure that performs cohesion on the sister chromatids in S phase and is maintained until metaphase (4). The Smc proteins contain ATPase (ABC type) at the terminal domains separated by a coiled coil domains and hinge domains which allows for interaction between the N- and C-terminals which are bridge by a heterodimer (Rad21 and Scc3 complex) (1). Cohesion process requires the Smc proteins to have the hinge domain, and ATPase activity in order for cohesin to associate with chromatin during the G1-phase (1,4). The Scc2-4 complex is required to load the cohesin complex onto chromatin (6). Scc complexes are used to mediate protein-protein interactions essential for cell division. Depletion in the protein results in severe premature sister chromatid separation (PCS) that will be discussed later (7). Once cohesion is established, Pds5 complex serves to maintain the sister chromatid structure through the G2-phase

Independent Assortment is the random assortment of chromosome that happens during Metaphase I (Meiosis). During this phase, the homologous chromosomes

Chromatids are 2 identical strands that are linked by the centromere. At the end of S-phase the chromosome is composed of 2 identical chromatids (sister chromatids)