Which of the following function is associated with calcium in plants? Formation of

Analyze the question: The question asks which structure or process in plants needs calcium as a mineral element.

Explain the concept: Calcium (Ca²⁺) is a macronutrient that plants absorb from the soil. Its main roles are:

• It forms calcium pectate, which cements neighbouring plant cells together in the middle lamella. This is part of the cell wall.
• It helps with cell division (spindle formation) and with the growth of root tips.
• It also helps maintain membrane stability and activates certain enzymes.

Check each option:

• A. Cell wall: Correct. Calcium pectate strengthens the cell wall and the middle lamella. A calcium deficiency causes weak stems, poor root growth, and "blossom end rot" in tomatoes.
• B. Ribosomes: Ribosomes are made of rRNA and protein, and magnesium helps hold their subunits together. Calcium is not the key element here.
• C. Proteins: Protein formation needs nitrogen (and sulphur in some amino acids). Calcium is not the main element.
• D. Cell membrane: Calcium does help stabilise membranes, but the cell membrane is built mainly from phospholipids and proteins. The classic textbook answer for calcium is the cell wall.

Answer: Option A, cell wall.

Exam tip: Link the minerals to their key roles:

• Ca → cell wall (calcium pectate)
• Mg → chlorophyll
• N → proteins
• P → ATP and nucleic acids
• Fe → chlorophyll synthesis