To investigate the effect of phosphate on cell division in root tips.
Phosphate ions (macronutrients) are needed large amounts by plants. They are required for root growth. For the root tips cells to divide, mitosis has to occur. Phosphate is needed for production of ATP which provides energy for mitosis to occur.
DNA replication occurs during interphase of the cell cycle. DNA is made up of nitrogen containing base, pentose sugar and phosphate group. The phosphate group forms part of the sugar phosphate backbone of DNA. Phosphate is therefore necessary in DNA replication.
During root growth, membranes also grow and they are made of phospholipids bi-layer which contains phosphates. Therefore, phosphates are needed their membranes to grow.
Mitosis is the process in which a eukaryotic cell's nucleus divides into two identical daughter nuclei.
There are five stages in mitosis.
1. Interphase, in this stage the DNA in the nucleus replicates. Therefore, the chromosomes consist of two identical chromatids each. However, they are invisible.
2. Prophase, in this stage chromosome becomes visible as they become shorter and thicker. Replicated centrioles move opposite poles of nucleus and a spindle is formed. Nuclear envelope and nucleolus disappear. Chromosomes become visible and the two chromatids are attached to each other at centromere.
3. Metaphase, in this stage chromosomes are attached to spindle by centromeres and line up across the equator. Chromosome separates at the centromere and the chromatids are pulled apart.
4. Anaphase, in this stage, chromatids are pulled by the microtubules and move to opposite poles.
5. Telophase, in this stage, chromatids reach the poles of the spindle and nuclear envelope reforms as well as nucleolus. The spindle eventually disappears. Nucleoli reappear. Mitosis is completed.
My hypothesis is that as there is more concentration of phosphate, the higher level of mitosis in root tips is.
When there is no phosphate presents in solution, there will be no mitosis end of root tip cells. This is because there is no phosphate for DNA replication or to make ATP or for the growth of membranes.
When there is phosphate presents in solution, there will be mitosis end of root tip cells. This is because there is phosphate for DNA replication or to make ATP or for the growth of membranes.
Therefore, the concentration of phosphate ions in solutions is proportional to the number of cells undergoing mitosis.
The input variable for this experiment is the concentration of phosphate. This is because the input of the concentration of phosphate will be different at each experiment.