Mitosis is easily observed in cells that are growing at a rapid pace such as whitefish blastula or onion root tips, which was used in this lab experiment. The root tips contain and area called the apical meristem that has the highest percentage of cells undergoing mitosis. The whitefish blastula is formed directly after the egg is fertilized. This is a period of rapid growth and numerous cellular divisions where mitosis can be observed. In mitosis the cell is in interphase, and have a distinct nucleus and nucleoli where the thin threads of chromatin thicken into distinct chromosomes and the nuclear evvelope breaks open releasing them into the cytoplasm. The firs signs of the spindle begin to appear, next the cell begins metaphase, where the spindle attaches to the Centromere of each chromosome and moves them to the same level in the middle of the cell. This level position is called the metaphase plate. Anaphase begins when the chromatids are separated and pulled to opposite poles, then the final stage is telophase. The nuclear envelope is reformed and the chromosomes gradually uncoil. Cytokinesis may occur, in which, a cleavage furrow will form and the two daughter cells will separate. Meiosis is more complex and involves two nuclear divisions. The…
As in mitosis * During S phase DNA is replicated giving rise to chromosome consisting * Prophase I * Spindle formation * Breakdown of nuclear envelope * Chromosomes condense * Each chromosome consists of 2 chromatids from S phase of interphase * Homologous chromosome pairs lie next to one another * Crossing over of chromatids between pairs (chiasma formation) *…
The chromosomes replicate and each DNA strand unzips into two strands, while free floating bases attach to the strands. Chromosomes begin to condense and attach to the membrane of the nucleus pairing up with their corresponding chromosome. Enzymes cut the DNA from the chromosomes at this time. The spindle fibers from and centrioles begin to separate to opposite ends. The chromosomes will now line up on either side of the metaphase plate. The chromosomes split to other ends of the cell. New nuclear membranes form at other ends of the cell. The rest of the cell divides and the division of the cell's cytoplasm has occurred. The chromosomes condense again, spindles and centrioles form, and membrane fragments disperse. Spindle fibers attach to the chromosomes. Centrioles are at opposite ends. Fibers are pulled to opposite ends of the cell. Chromatids arrive at opposite ends and new nuclear membranes form. The rest of the cell continues to divide and there are now four daughter cells. Following these steps of meiosis will help us be able to have a better understanding and awareness of who the parents are of Mrs.…
During the metaphase of mitosis, sister chromatids are visible and attach to each other at the centromere.…
Eukaryotic cells go through Interphase and Mitosis. Interphase is further subdivided into 3 stages, G1 (first gap), S (synthesis of DNA), and G2 (second gap). In all 3 sub phases cell growth happens and organelles like mitochondria are replicated. DNA, however, is only synthesized during the S phase. DNA replication is started by Helicase which unwinds the double helix at replication forks. Topoisomerase is used to loosen the tension at the ends of the bubble, in order to correct for over winding ahead of the replication forks. Primase then synthesizes an RNA primer which the DNA polymerase III will use to lay down bases, synthesizing a new strand. DNA polymerase I will then remove the primer and DNA Ligase will join ends of DNA synthesized from different replication forks. Because DNA can only synthesize from 5'->3', there is a leading strand and lagging strand which creates Okazaki fragments that are later joined together by DNA Ligase. After DNA is replicated proofreading enzymes will check and repair any mistakes that occurred during replication. After S phase is the G2 phase where the cell grows even larger. G2 is followed by mitosis, which is subdivided into 5 parts: prophase, metaphase, anaphase, telophase, and cytokinesis. In prophase, chromatin condenses and the nucleoli disappears. What we know as chromosomes, which consist of two identical sister chromatids joined together at centromers, begin to appear. Mitotic spindle is formed and the centromers start moving to opposite poles, propelled by the lengthening microtubules that they shoot out. In metaphase, the longest stage of mitosis, the chromosomes line up on the metaphase plate and the centromeres have already migrated to opposite poles.…
Question: How does mitosis produce new cells, and how is mitosis the same and different?…
This answer can be found on page 232, “Prophase - The mitotic spindle begins to form. IT is composed of the centrosomes and microtubules that extend from them.”…
The Anaphase stage of is happening, A spindle is a microtubule structure that brings about chromosomal movement during nuclear division.…
Mitosis and meiosis can be seen with light microscopes. the different stages of mitosis; when the spindle fibers are formed in Prophase, the chromosomes lining up along the middle of the cell in Metaphase, the chromatids separating and moving to opposite sides of the cell in Anaphase and finally the cytoplasm splitting into 2 genetically identical daughter cells in Telophase.…
10. For cells to stay the same size from generation to generation, what two things must be coordinated?…
Mitosis is the process by which the nucleus of the cell is divided into two nuclei, each with the same number and kinds of chromosomes as the parent cell.…
* A gene's specific location along the length of a chromosome is called the gene's locus…
There is two stages in M-phase; the first stage is called mitosis. Mitosis is the nuclear division of the cell, separating the two copies of the genome and forming daughter nuclei. There are four stages in mitosis: prophase, metaphase, anaphase and telophase. Multiple changes occur in prophase including the coiling of the chromatin into chromosomes, the disappearance of the nuclear envelope and nucleoli, the migration of the centrosomes toward opposite poles and the construction of spindle apparatus, which are composed of protein fibers called microtubules. The next stage is called metaphase, where the chromosomes line up at the middle of the cell because the microtubules push and pull them there. The third stage, anaphase, consists of sister chromatids separating and being pulled toward opposite poles. The last phase of mitosis is telophase, which is when the chromosomes uncoil resulting in chromatin. During telophase two new nuclear enveloped appear and spindle apparatus breaks down (Mrs. Weiland, 11/19/15).…
Puppies increase in size as their cells grow and divide. Almost all cells complete a full cell cycle that includes interphase and cell division. In interphase, cells serve their specialized functions, grow, and copy their genetic material. Mitosis is the first stage of cell division, in which the copied chromosomes are separated into two new nuclei. Then in cytokinesis the cell divides into two daughter cells. If no mutations or errors occur, the genetic material in each daughter cell is identical to what was in the original cell.…
1. Interphase: DNA has formed already, but it remains in the simple form of chromatin. Chromatins are structures that are loosely coiled in the cell.3 I also observed during my lab that this was the only stage where I could still see a nucleus and nucleolus intact within the cell; this is because it’s the only stage where the nuclear membrane has not broken apart yet to begin forming a new cell.3…