Count dividing and total cells from a root-tip image or table, then calculate the percentage and rearrange the equation to find missing cell numbers or compare treatments.
Flowering plants produce seeds that can be stored in a seed bank. This is done to conserve the biodiversity of plants.
The longer seeds are stored in seed banks, the less likely they are to germinate. This is due to ageing.
Ageing of seeds can affect the growth of roots when the seeds germinate.
Determining the mitotic index of roots is one way to study growth of roots.
Describe how the mitotic index of roots can be determined.
Seeds can be treated to artificially age them.
In an investigation, untreated and treated samples of seeds were germinated and the roots allowed to grow.
Roots of different lengths from the untreated seeds, seeds treated for 4 days and seeds treated for 14 days were selected.
The mitotic index of these roots was determined.
The graph shows the results of this investigation.
There were 14 cells undergoing mitosis in 8 mm roots from seeds treated for 4 days. Calculate the total number of cells that were counted when the mitotic index was determined.
(3)
Total cells counted