Analyse how repeated mitosis, meristem activity and mitotic-index evidence explain tissue growth, regeneration and inhibition in IB Biology HL D2.1.12.
The photomicrograph shows a section of onion (Allium cepa) root tip cells.
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Describe how a mitotic index could be obtained from this image.
Cadmium is a heavy metal that can cause environmental problems. Cadmium ions are released from various human activities such as the release of sewage sludge, mining and industrial processes. Plants take up cadmium ions and they enter food chains.
A study was carried out to look at the effect of various concentrations of cadmium ions on the mitotic index of the apical meristem of root cells from 4-day-old wheat (Triticum aestivum) seedlings.
State the effect of cadmium ion concentration on the mitotic index of root cells from wheat seedlings.
Suggest the effect the change in mitotic index would have on the wheat plant.