Plant cell mitosis experimental steps - Database & Sql Blog Articles

[Cell mitotic memory sputum] (1) Pre-mitotic stage: Membrane kernel disappears in the middle of the two bodies: Defining the number of equator Qi late: Point splitting and increasing the end of the two poles: two disappearing and two beginnings (2) Splitting period Pre-orbital: membrane Ren lost, two manifestations; medium-term: in the body column, the number is clear; late: point splitting increase, body average; end period: pre-reverse, medium-scale board (plant). The central organelle involved in mitosis - related to the formation of the spindle; the mitochondria - related to the provision of energy; the Golgi - the ribosome associated with the newly formed cell wall of the plant - is related to the protein required for interphase DNA replication Exploring and finding out the lateral roots of broad beans is an ideal way to observe plant cell mitosis materials. The steps are as follows: 1 The seedlings of broad bean seedlings and lateral roots are selected from mold-free and pest-free broad bean seeds, soaked in clear water for 24 hours, and taken out into the wet yellow sand or river sand. The depth of broad beans buried in the sand is 2~3 cm. Cultivate at room temperature (high temperature in summer can be placed in a cool place, low temperature in winter can be placed in a sheltered place in the sun, conditional schools can be placed in a 25 °C incubator), sprinkle a small amount of water every day to prevent sand from drying out . When the main root grows to 2 to 3 cm, the broad bean seedlings are pulled out, and the growth point of the main root tip is cut to promote the growth of the lateral roots, and then the seedlings are buried in the sand to continue the cultivation. When the temperature is suitable, 7~2cm lateral roots can be grown around 7 days (including soaking time), and generally 6~10 roots can be found on each main root. If the sand is kept moist and placed in a room temperature environment, the lateral roots can maintain vigorous growth within 2 to 3 weeks, and the cell division activity in the meristem is still active. 2 Take 1 to 2 cm long and thick lateral roots, wash the sand adhering to it in clean water, and use the blade to cut the tip of the root into two. The length of the incision is 2~3mm. The purpose of the longitudinal apex is to fully dissociate the internal tissue of the apical and to shorten the processing time in the dissociation fluid. 3 Dissociation The entire root tip after longitudinal sectioning was placed in a 1 mol/L HCl solution and dissociated at room temperature for 6-8 min. The length of the dissociation time is related to the room temperature, and when the room temperature is high, the time can be appropriately shortened, and vice versa. Generally, the root tip is completely soft. 4 Rinse until the root tip is soft, remove it with tweezers, rinse in clean water for 2-3 minutes. 5 Dyeing Put the rinsed root tip in the center of the slide, cut off the 2~3mm root tip with a blade, use water-absorbent paper to absorb the water around the root tip, add 1~2 drops of modified carbolic acid magenta dye solution, at room temperature. Dyeing for 6 to 10 minutes. In order to further improve the coloring effect of the dye on the chromosome, the slide can be slowly heated for a few minutes above the flame of the alcohol lamp, so that the dye solution does not boil, and the heating is stopped when the dye solution is about to evaporate. 6 To absorb excess dye around the root tip with absorbent paper, add 1 drop of water, blot dry, add 1 drop of water, cover the coverslip, add 1 slide on the cover slip, and press hard . 7 Microscopic observation The prepared film is first found in the growth point area under the low power microscope. The characteristics of this area are: the cells are slightly square, and are closely packed into bundles. The spacing between the nucleus and the nucleus ≤ nuclear diameter; the nuclear spacing ≥ 2 In the region of the nucleus diameter, there are few cells in the split phase. After finding the growth point area, it was replaced with a high power microscope to observe the cells of each phase of the split phase. 8 Dyeing effect of different staining solutions The lateral roots of Vicia faba L. were stained with crystal violet, acetate magenta, lichen acetate and modified carbolic acid magenta. The results showed that the modified carrageenan fuchsin dyeing effect was the best; while the other three dyeing solutions were used, the chromosome morphology The clarity is slightly worse than the former. 9 Differences in the observation effect between broad bean and lateral roots The main roots of broad bean and broad bean have short cultivation time and large roots. In the past, broad beans were used as mitotic observation materials, and the main roots were used. We treated the main roots with different dissociation liquids and staining solutions. The results showed that the cytoplasmic staining particles of the main root meristem cells were numerous, resulting in deep background coloration, and it was difficult to observe the chromosome morphology, and the experimental effect was poor. After the lateral root staining, the background coloration was shallow and the chromosome morphology was clear. The reason for the poor observation of the main root may be due to improper extraction of the material or the concentration of the staining solution or the difference in the cytoplasmic composition of the cells. The real reason is for further study.

Through several rounds of experimental teaching practice, the lateral root of Vicia faba L. is an ideal material for observing mitosis of plant cells. Compared with onion, it shows the following advantages: l) apical for experimental use (with a large number Divided phase cells) Maintaining a long period of time at room temperature to keep the culture sand moist, the time of growing the lateral roots of the cleavage activity on the main root can be maintained for 3 weeks; 2) The proliferative phase of the split phase lasts for a long time from 9 am to 6 pm At any time, a large number of split-phase cells can be observed by sampling, which avoids the teacher's use of onion as a material and has to use the rest time to pick up and fix at noon or night, reducing the workload of the teacher; The observation of fresh materials not only improves the experimental effect, but also enhances the intuitiveness of teaching. In addition, the proportion of the lateral root cell of the broad bean is high. Generally, several different phases of the dividing phase cells are visible in one field of view, and some of the tableting parts are available. The mitotic cells can be seen in one field of view; 3) stained with modified carbolic acid magenta, the cytoplasm is lightly stained, and stained The color body is darkly colored, the chromosome is large, the field of view is clear, and it is easy to observe. 4) The material is easy to obtain, has no seasonal restriction, is convenient to culture, has high seed germination rate and large rooting amount.