How is calcium described in terms of its mobility in plants?

Calcium is characterized as having low mobility within plants. This means that calcium tends to accumulate in areas such as leaves or developing tissues and does not readily translocate or move throughout the plant's various parts. Unlike other nutrients that can be moved from older tissues to younger ones to meet the plant's needs, calcium primarily remains in the tissues where it was initially absorbed. This limited mobility is significant, especially for growth and development, as deficiencies in calcium can lead to developmental issues such as blossom-end rot in fruits and poor cell wall structure.

This understanding highlights the importance of ensuring adequate calcium availability in the soil and proper management practices to avoid deficiencies during crucial growth stages, particularly in rapidly growing tissues. Other options, which suggest that calcium is highly mobile or that its mobility varies, do not align with the established understanding of calcium's characteristics in plant physiology.