Biology Mitosis Lab

Mitosis and litotes Cell Division Lab Part 1-MITOSIS summary In this experiment first the symbolizes of an onion cellphone undergoing mitosis be going to be observed and every stage is going to be detected and drawn on paper. A brief description to what is going on should be attached to the pictures. This is important to understand the basics of cell division which is necessary growth,repair and asexual reproduction. Second the number of cells undergoing each phase is going to be counted to figure out in which phase the cell remains the most.If interphase is the stage in which the cell grows and prep bes for cell division then the number of cells undergoing interphase entrust be the most. After cells were counted it came out that indeed the number of cells in interphase is the most followed by prophase, metaphase=anaphase and telophase. This makes us come to the conclusion that the longest phase for a cell is interphase in which the cell grows and gets make up to divide. The se cond longest in prophase in which the chromatin fibers start to form chromosomes. The other phases which follow are very short and quick. designMitosis is the division of the nucleus,providing equal amounts of nuclear material to the missy cells,in eukaryotes. Equal amounts of chromosomes are provided for the forming daughter cells by replicating the DNA and chromosomes before the division. Mitosis advances in somatic cells and produces 2 daughter cells. The whole process of mitosis consists of 5 stages. 1-Interphaseis the stage in which the cell rests and gets ready for division. Consists of 3 parts. -G1number of organelles double,size increases. At the end of this phase is a G1 checkpoint which controls is the cell is ready for division or not. Schromosomes are duplicated. -G2special proteins and enzymes for cell division are synthesized. 2-ProphaseCentrioles move to icy poles of the cell. Form spindle fibers whichll give-up the ghost the microtubules holding the centromere. Chromosomes become visible as long threads and become shorter and thicker. Each chromosome joins another one forming sister chromatids attached in the middle by a centromere. atomic membrane dissolves. 3-Metaphasespindle fibers from the centrioles attach to the chromosomes at the kinetochore lining the chromosomes in the center of the cell. -Anaphase The centromeres divide and the sister chromatids separate.The spindle fibers full the chromosomes to antithetical poles of the cell. 5-Telophase When chromosomes have reached opposite poles a nuclear membrane forms around them. Chromosomes then untwist and stretch becoming invisible again. Spindle fibers break down. At the end of mitosis cytokinesis takes place which is the organization of a cleaved membrane between the two new formed cells to separate them. Materials -onion root tip cells -microscope Procedure 1-Observe the onion root tips under the microscope first at 100X and then at 400X. 2-Draw each phase of mitosis you see. -Wri te a brief description of what you observe in each phase under the picture. 4-Under 400X count the number of cells undergoing divers(prenominal) phases. Record data. 5-Calculate the total number of cells. 6-Calculate the percent amount of time the cells spend in each phase. Analysis The data we collected shows that 52% of the cells were in stage interphase. This indicates that more than the half of the cells are recovering from their previous division and preparing to divide again. 40% of the cells were in the second phase prophase while the other phases had a cell percentage number of 2%. This denotes that prophase is the second longest phase.This can be because it takes a longer time to duplicate the chromosomes than simply lining them up and draw them apart. Conclusion Our hypothesis that if interphase is the resting phase then itll be the longest was shown true by the data we got from the onion root tips. The number of cells undergoing interphase had the highest number encou raging our hypothesis. The complement of interphase is very important for organisms. If interphase isnt completed before division or if something goes wrong during it many problems could occur like mutations or other things which would shanghai the proper functioning of the organism.The possibility of errors emerging in this experiment is very low. The only errors could be caused if something was wrong with the microscopes lens or objective. Another thing to be researched could be what factors effect mitosis and if the same process would still occur in a different environment. Part 2-MEIOSIS In this part the concept of litotes which is the innate of sexual reproduction is going to be observed by using Sondaria fimicola a certain type of mushroom. The colors of the ascospores before and after meiosis are going to be observed to see whether at that place is crossing over or not.If meiosis is occurring then the newly formed sequences will look different then the ones to begin with. Observe the S. fimicola undergoing meiosis. Look at the ascospores after meiosis and notice the pattern. If the changes are in a 44 manner there is no crossing over. If any series of 2 like 242 or 2222 occur it means that crossing over took place. The results we got were composed of different sequences including both patterns with 4s and 2s which means that crossing over took place. *Because S. fimicola was not available for the lab,cards with pictures of it undergoing meiosis were used. IntroductionMeiosis is a type of cell division which provides genetic variation by reducing the chromosome number to half and creating haploid cells. by and by on a male and female haploid cell will join to form a diploid cell with the right number of chromosomes. Meiosis consists of one DNA replication and two nuclear divisions resulting in 4 daughter cells. The process which provides for genetic variation is crossing over. Crossing over occurs in the early stages when homologous chromosomes mov e together so that their chromatids form a tetrad. This is called synapsis and allows for the exchange of chromosome sections.In our case the crossing overs will result in different colorings of the ascospores of the S. fimicoli. Materials -Microscope -S. fimicola meiosis cards Procedure 1-Study the different phases of meiosis on the cards. 2-Notice the difference between ascospores with sequences of 4s and 2s. 3-Count the amount of different sequences present. 4-From the data you gathered depend the percentage of asci showing crossover. Analysis Out of a total from 26 sequences only 6 were made up of 4s while 20 were composed of different structures of 2s. This tells us that 77% of the asci showed crossing over while 23% did not.Conclusion 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 2s emerged from the first pattern of 4s is prove that crossing over t ook place. Genetic variation is very important because it is a way of natural selection. Beneficial and strong genes are selected while the others are eliminated. (Survival of the fittest) For afterlife research it could be researched if the crossing over happens randomly or whether there is some order to it and if could be controlled to get a 100% functioning ,ideal organism.