Meiosis IN A LILY - LAB REPORT PDF

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MEIOSIS IN A LILY’S ANTHER

OBJECTIVES To observe and identify the stages of meiosis in a lily’s anther. Besides, we should be able to observe, identify and draw the stages of meiosis in a lily’s anther.

INTRODUCTION In this study, meiosis will be studied as it occurs in the development of mature pollen grains of flowering plants. This pollen grains give the rise to male gametes, which fuse with an egg to produce a zygote.

MATERIALS 1) Light microscope 2) Methylated spirit lamp 3) Slide and cover slip 4) Watch glass 5) Blade 6) Mounted needle 7) Acetic orcein 8) 1 molar HCl 9) Lily’s anther 10) Slide of Lilium second division 11) Slide of cross-section of ovary, second division.

PROCEDURE 1) The lily’s anther has cut off. 2) The lily’s antyher has placed in a watch glass containing acetic orcein stain and HCI in the approximately proportions of the ten parts of stain to one part of acid. 3) The lily has warm for five minutes on the spirit lamp and the acid helps to macerate the tissue so that the stain can be easily absorbed. 4) 3 mm part of the lily’s anther has cut.

5) Two drops of acetic orcein has added to the lily’s anther on the slide. 6) The lily’s anther has broke with a needle so as to spread it out as thinly as possible. 7) The cover slip has put and cover it with the filter paper and gently squash. 8) The slide on the spirit lamp has warmed about ten seconds to intensify the staining. The slide should be very warm, but not too hot to touch. 9) The stages in meiosis has examined. 10) A label diagram has draw to record the stage of meiosis in Table 7.1. 11) A notes the changes that occur in every stage in meiosis besides the labeled diagram has wrote in Table 7.1.

QUESTIONS 1) Where else you can find this process in a lily? - In the ovul 2) How do you identify the meiotic division that occurs in the lily’s anther? - based on their pollan sacs 3) Give the significance of meiotic process in organisms. - it maintain the same chromosome number in the sexually reproducing organisms. 4) List the differences between the mitotic and meiotic process that occur in a lily.

Mitotic Produce gametes

Meiotic Divide the chromosomes

DISCUSSION From this experiment, the prophase I, telophase I and telophase II was observed. In prophase I, this stages was determined because of the chromosome are condensed and the color of the center of the cell are darker than each cell. For telophase I, the cell is dividing into 2 clusters and for telophase II, there are four clusters in one cells. In metaphase I, the pair of homologous chromosome aligns along the metaphase plate in double row. In anaphase I, kinetochore microtubules shorten and homologous pairs are pulling apart. One duplicated homologue goes to the other poles.

In telophase I, the separated homologues form a cluster at each poles of the cell, and the nuclear membrane re-forms around each daughter cell nucleus. Cytokinesis may occur. During prophase II, a new spindle apparatus forms in each cells and the nuclear membrane breaks down and disappears. In metaphase II, a complete spindle apparatus is in place in each cell. When microtubules are shortening in anaphase II, the centromers split and sister chromatids are pulled to opposite poles of the cells. In telophase II, the nuclear membranes re-form around four different clusters of chromosomes. After cytokinesis, four haploid cells are produce.

CONCLUSION Meiosis begins with a germ cell in interphase. Although it will not become apparent until later in meiosis, the cell has duplicated its DNA during the interphase period, so all chromosomes are actually doubled. At the completion of meiosis, four gametes, each containing a haploid number (n) of chromosomes, have potentially been produced. The diploid (2n) state can now be restored through the union of two haploid gametes in sexual reproduction....