Observing Mitosis | Mitosis | Cell Cycle

 

onion root tip mitosis lab report

Mitosis occurs in whitefish blastula and onion root tip, and it is easily observable. Meiosis and crossing over occurs in the production of gametes and spores. Materials This lab requires prepared slides of whitefish blastula, onion root tips, and Sordaria, pencil, paper, a light microscope, and a chromosome simulation kit. Methods. Stages of Mitosis Lab Report - Free download as Word Doc .doc /.docx), PDF File .pdf), Text File .txt) or read online for free. mitosis4/5(4). This lab was an experiment designed to analyze how many cells could be observed in each part of mitosis for different areas of an onion root. First, with a prepared slide, area X and Y were located and each counted and recorded of what stages were observed. Then, another onion root tip was prepared and area Z was located.


Stages of Mitosis Lab Report | Mitosis | Cell Cycle


Introduction There are two types of nuclear division, mitosis and meiosis. Mitosis is the first of these studied in this lab. It is easily observed in cells that are growing at a rapid pace such onion root tip mitosis lab report whitefish blastula or onion root tips, which are used in this lab. The root tips contain an 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. Just before mitosis the cell is in interphase. In this part of the cell cycle the cell will have a distinct nucleus and nucleoli where the thin threads of chromatin are duplicated.

After duplication the cell is ready to begin mitosis and its starts with a step called prophase. In prophase, the chromatin thicken into distinct chromosomes and the nuclear envelope breaks open releasing them into the cytoplasm.

The first 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 case, a cleavage furrow will form and the two daughter cells will separate. Meiosis is more complex and involves two nuclear divisions. The two divisions are called Meiosis I and Meiosis II and they result in the production of four haploid gametes. This process allows increased genetic variation due to crossing over where genes can be exchanged. The process, like mitosis, depends on interphase to replicate the DNA.

Meiosis begins with Prophase I. In this stage, homologous chromosomes move together to form a tetrad and synapsis begins. This is where crossing over occurs resulting in the recombination of genes. Onion root tip mitosis lab report I moves the tetrads to the metaphase plate in the middle of the cell, and Anaphase I reduces the tetrads to their original two stranded form and moves them to opposite poles.

Telophase I then prepares the cell for its second division. Meiosis II generally resembles mitosis except that the daughter cells are haploid instead of diploid. DNA replication does not occur in Interphase II, and prophase, metaphase, onion root tip mitosis lab report, anaphase, and telophase occur as usual.

The only change is the number of chromosomes. The process of crossing over can be easily studied in Sordaria fimicola, an ascomycete fungus. Sordaria form a set of eight ascospores called an ascus. They are contained in a perithecium until they are mature and ready for release. Crossing over can be observed in the arrangement and color of these asci. If an ascus has four tan ascospores in a row and four black ascospores in a row arrangementthen no crossing over had taken place.

However, if the asci has black and tan onion root tip mitosis lab report in sets of two arrangement or two pairs of black ascospores and four tan ascospores in the middle onion root tip mitosis lab reportthen crossing over had taken place. Hypothesis Mitosis occurs in whitefish blastula and onion root tip, and it is easily observable.

Meiosis and crossing over occurs in the production of gametes and spores. Materials This lab requires prepared slides of whitefish blastula, onion root tips, and Sordaria, pencil, paper, a light microscope, and a chromosome simulation kit.

Prepared slides of whitefish blastula and onion root tips were observed under the 10X and 40X objectives. A cell in each stage of mitosis were identified, and then sketched. Using a high power objective, every cell in a field of view was observed. Each cell was counted as being in one of the stages of mitosis and recorded. At least cells and 3 fields of vision were counted and recorded. Next, the percentage of cells in each stage was recorded and the amount of time spent in each phase was calculated.

In this part of the lab, a chromosome simulation kit was used to demonstrate meiosis. Two strands of the same color were connected to simulate DNA replication in both of the homologous pairs. Next, onion root tip mitosis lab report, the chromosomes were entwined to represent synapsis. Sections of beads were switched between the pairs as in crossing over and were aligned at the equator. Next, anaphase was simulated as onion root tip mitosis lab report homologous pairs were separated and then telophase was simulated by pushing the chromosomes into two separate cells circles.

Meiosis II was simulated as well. The chromosomes again move to the equator and in Anaphase II the two chromatids were separated and moved to opposite poles. Telophase II separates them into four different cells. Prepared slides of Sordaria fimicola were observed under a light microscope. Over asci were identified as either or asci showing crossover and recorded, onion root tip mitosis lab report.

The percentage of each and the map units were calculated. Interphase 42 36 47 Prophase 10 13 18 41 Metaphase 6 5 4 15 7. Anaphase 2 3 2 7 3. Telophase 7 5 4 16 7, onion root tip mitosis lab report. Chromosome number of parent cells Diploid 2n Diploid 2n. Chromosome number of daughter cells Diploid 2n Haploid n. Purpose Growth and repair Production of gametes or spores. Simulation of the Meiosis I. Gene to Centromere Distance Map Units 53 64 The whole process of mitosis is a series of steps that split the nucleus into two separate nuclei at opposite poles.

The blastula is a hollow ball of cells that forms from the fertilization of an egg. Rapid growth occurs and numerous cellular divisions making mitosis in various stages easy to observe. Onion root tips are also a region of high percentage of cells going through mitosis because this is where most of the root growth takes place. If your observations had not been restricted to the area of the root tip that is actively dividing, how would your results differ?

There would be virtually no cells undergoing division, so many more of the cells observed would have been in interphase where they elongate an differentiate. Based on the data in Table 3. Prophase is the longest stage of mitosis and then going in sequential order each decreases in the length of time it takes to complete.

In mitosis, the nucleus is only divided once, while in meiosis the nucleus is divided twice. Another difference is that mitosis produces two identical daughter cells, but meiosis produces up to four different daughter cells. Also, synapsis and crossing over do not take place in mitosis, but do take place in meiosis. Meiosis I begins with a tetrad and separates the homologous pairs.

Meiosis II separates the two sister chromatids. In meiosis the chromosome number is reduced to n so that it can be fertilized. Also, meiosis allows for crossing over, which results in variations in organisms. Error Analysis There was little chance for error in this lab. It was mostly observation and sketching. However in Exercise 3A. The calculations obtained for its time were too high; it should have been the shortest stage of meiosis. This may be caused by misidentifying the stages or counting the daughter cells as two different cells.

Misidentification could have caused errors in the other parts of this lab as well. Discussion and Conclusion Mitosis was observed and timed in Lab 3A. The stages of mitosis are prophase, metaphase, anaphase, and telophase, prophase being the longest and telophase the shortest. Meiosis was simulated in Lab 3B and then crossing over was observed in Sordaria and the map units were determined, onion root tip mitosis lab report.

The gene to centromere distance in the Sordaria was Skip to content. Mitosis and Meiosis. Previous Previous post: Invertebrate Notes. Pin It on Pinterest. Cookies This website uses cookies to ensure you get the best experience on our website. Learn more, onion root tip mitosis lab report.

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Lab 3 Sample Ap Mitosis & Meiosis - BIOLOGY JUNCTION

 

onion root tip mitosis lab report

 

report on observing mitosis (Autosaved) Lab Report Chemist Chapter 7. the cell is observed and the mitotic rate is recorded. The preparation of onion root tip freezes the mitosis process at one point, thus, the higher the percentage of the cell in one stage, the higher the time spent on that stage. Mitosis Onion Root Tip Lab. Uploaded 5/5(17). In this lab you will be observing plant cells (onion) in the various stages of mitosis, and make time calculations based on the data you collect. MATERIALS: Microscope Prepared slides of a longitudinal section of Allium (onion) root tip. You can obtain these from any science supply company. Stages of Mitosis Lab Report - Free download as Word Doc .doc /.docx), PDF File .pdf), Text File .txt) or read online for free. mitosis4/5(4).