MITOSISMEIOSIS Lab Report Example | Topics and Well Written Essays - 1000 words

MITOSISMEIOSIS - Lab Report ExampleThis is fol firsted by separation of daughter cadres. litotes is the type of prison cell division by which germ cells (eggs and sperm) are produced. Meiosis was first observed by the Belgian cytologist Pierre-Joseph van Beneden in 1887. Meiosis involves a reduction in the amount of genetic material. It comprises two successive nuclear divisions with only one round of DNA replication. One parent cell, at the end of one meiotic division, produces four daughter cells. Daughter cells have half the number of chromosomes found in the original parent cell and with crossing over, are genetically different. Meiosis differs from mitosis primarily because there are two cell divisions in meiosis, resulting in cells with a haploid number of chromosomes.Cell division is especially rapid in the growing spreadeagle tips of sprouting seeds. The chromosomes in dividing alkali tip cells can be demonstrated if, after sprouting seeds or bulbs,and harvesting the you ng root tips, and then fix, acid digest, stain, squash, and view them under a microscope.The root tip is the place of intense mitotic activity. This region is three dimensional and individual cells cannot be seen. It is therefore necessary to separate the cells out into a lean layer. Plant cells are glued together by the middle lamella of calcium pectate. Hydrochloric acid will dissolve this calcium pectate but leave the cellulose cell wall unaffected. In addition the acid kills and fixes the cell contents in position. Acetic orcein stains nuclei and not the cytoplasm.1. The apical 5mm from the tip of a growing lateral root of a broad bean was carefully cut.2. The root tip was placed in a watch glass containing acetic orcein stain and 1mol dm-3 hydrochloric acid in the approximate proportions 10 parts stain to 1 part acid.3. Allowed to warm for five minutes by passing repeatedly with a low Bunsen flame. 4. The fixed root tip was placed on a microscope slide and two drops of acetic orcein were added. 5. The root tip was broken up without destroying the arranging of the cells, and the root tip was spread out as thinly as possible.6. A cover slip was placed over the root tip, and covered it with blotting cover and squashed gently by pushing down on the cover slip. 7. The slide was warmed gently to intensify the stain, by quickly passing through a low Bunsen burner flame a few times.8. The slide was examined for identifying any stage of mitosis. ResultsMitosisThe four phases of mitosis- Prophase, Metaphase, Anaphase and Telophase- were observed under the microscope. The different phases were identified establish on the unique chromatin organization features1. Interphase Each chromosome undergoes replication, making an identical copy of itself. At this point, the chromosomes are still long and thin, and are not macroscopic inside the nucleus. Cells spend most of their life in this non-reproductive phase.2. Prophase The chromosomes coil and shorten, and become visible. It becomes apparent that the chromosomes have duplicated. Pairs of identical chromosomes remain