The Replication Of Cell The Cell Cycle 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

Interphase: This particular stage is divided into three phases, G1 (first gap), S (synthesis), and G2 (second gap). During all three phases, the cell grows by producing proteins and other organelles within the cytoplasm. However, chromosomes are replicated only during the S phase. In all, a cell grows (G1), continues to grow as it duplicates its

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

2. In which phases of mitosis are sister chromatids visible, and attached to each other at the centromere?

Although mitosis is just a fraction of time compared to interphase it can be divided into four distinct subphases. If we start viewing a cell under a brightfield microscope right at the end of interphase subphase G2 we would see that throughout the interphase process (fig 1) the cell has grown considerably in size due to production of extra mitochondria and endoplasmic reticulum. The cell has also gone through the labor of duplicating all of its chromosomes, a process known as DNA synthesis. Now that the cell has made all of these preparations it's time to start prophase (fig 2), the first stage of the mitotic phase. This stage is visibly identified by the chromatin becoming the tightly formed chromosomes. During the lab we were able to view these newly formed chromosomes best on the onion root tip

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

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

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.

1. The feature that most clearly separates eukaryotes from prokaryotes is the presence of _______ in eukaryotic cells.

PC3 (8×104  cells/well) and LNCaP (3×105  cells/well) cells were seeded in 6-well plates in 1.5  mL of complete growth media. Cells were treated with 2.5 μM of free sorafenib or an equivalent sorafenib concentration of SMA-Sor, 3 μM of free nilotinib or an equivalent nilotinib concentration of SMA-Nilo, DMSO or SMA for 48  h. Cell cycle distribution was assessed using propidium iodide staining, as previously described {Somers-Edgar, 2011 #82}. Samples were analysed using a FACScalibur flow cytometer (BD Biosciences, San Jose, CA, USA) and the proportion of cells in each of G0/G1-, S- and G2/M-phases were determined using CellQuest Pro software (BD Biosciences, San Jose, CA, USA).

18) During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles? A) anaphase B) metaphase C) telophase D) prophase 19) At the start of mitotic anaphase, A) the chromatid DNA replicates. B) the centromeres of each chromosome come apart. C) nuclear envelopes begin to form around the chromosomes. D) equivalent and complete collections of chromosomes have reached the two poles.

There are four stages of mitosis: prophase, metaphase, anaphase, and telophase. In prophase the chromatin shrinks into separate chromosomes, and the nuclear envelope breaks down and forms

The cell cycle consists of the G0 phase and the interphase that includes the three sub-phases, G1, S, and G2, and the M phase (fig. 4). The G0 phase or the quiescent phase is when a cell has exited the cell cycle and/or undergoes terminal differentiation. Cell division occurs during the relatively brief M phase, which is followed by the G1 phase. The G1 phase is the main period of cell growth, and it covers the longest part of the cell cycle. The S phase is when DNA synthetizes. When this phase is complete, the cell contains double the amount of DNA, which leads to the relatively short G2 phase. The G2 phase is the

Eukaryotes undergo asexual cellular reproduction to grow in size or replace damaged tissues. The first process in the cell's life cycle is mitosis. When the chromosomes in the nucleus are duplicated, it creates two identical sister cells from the one progenitor cell. Mitosis is broken down into four phases: prophase, metaphase, anaphase, and telophase. DNA duplication occurs during a stage called interphase. Once completing the exact duplication of the cell, it is followed by cytokinesis, when the cytoplasm of the parent cell divides into two daughter cells. In plant cells, a cell plate forms between each new cell.

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