An experiment into looking at cell division in a garlic root tip
Introduction/Aim
The aim of this experiment is to see dividing cells at various stages, demonstrating mitosis in a garlic root tip. A garlic root tip is a good example to demonstrate mitosis because, when the root is in water, several roots are produced over a short period of time. Mitosis is the process of ordinary cell division used for growth and repair. The root tip of any plant contains meristem tissue. This is where the plants mitotic division takes place, (unlike animal cells, where it can occur anywhere). The plants individual cells cannot be seen as they have many layers and therefore must be squashed in order to see mitosis occurring. Mitosis has several stages. The first stage is interpahse; here the nucleolus is sometimes visible. The chromosomes are too thread-like for clear visibility under the microscope; the cell has a normal appearance of a non-dividing cell. The second stage is prophase, the nucleolus disappears and the chromosomes become more visible. The centrioles begin to move at opposite ends of the cell and the spindle fibers being to form. Spindle fibers are a collection of attached to a during , which are responsible for the movement of the to opposite poles. (http://en.mimi.hu/index.html) The third stage is metaphase. Here the chromosomes are beginning to arrange themselves on the equator and the chromatids (an exact copy of one half of the chromosome) being to dram apart at the centromere region (a region of the chromosome, where two identical chromosomes are attached to a spindle fiber). The fourth stage is anaphase, the paired chromosomes part and start to move to opposite ends of the poles. The fifth phase is telophase, the chromatids arrive at opposite poles of the cell and the chromosomes are no longer visible. The sixth and final stage of mitosis is called cytokenesis. Here the plant cells divide into two daughter cells by building two new cell walls (unlike animal cells which pinch into two). The chromosomes eventually regain their thread-like form and the cell division process is ready to start again.
