Question

A star-shaped mass of crystals of calcium oxalate found in the cells of Chenopodium and
Colocasia is called
A. Crystal sand
B. Sphaeraphides
C. Druse
D. Both B and C

Answer 1

Hint:-Calcium oxalate is an oxalate calcium salt with the molecular formula: \[Ca{C_2}{O_4}\cdot{\left( {{H_2}O} \right)_X}\], where x ranges from 0 to 3. Calcium oxalate (in archaic terms, lime oxalate). Colourless or white are both types. Naturally, the monohydrate occurs as the mineral whewellite, producing envelope-shaped crystals, known as raphides in plants. The rarer hydrates and trihydrates (mineral: caoxite) are also recognized.

Complete Answer:-
Many plants have the ability to accumulate calcium oxalate as it has been recorded in more than 1000 distinct genera of plants. The accumulation of calcium oxalate is related to calcium (\[C{a^{2 + }}\]) detoxification in the plant.
Calcium oxalate (Beerstone) is a brownish precipitate that appears to collect in vats, barrels, and other vessels used in beer brewing. Beerstone can leave an unsanitary surface that can harbour microorganisms if not removed in a cleaning process. Beerstone consists of calcium and magnesium salts and other organic compounds leftover from the brewing process; it facilitates the production of undesirable microorganisms that can adversely influence the flavour of a batch of beer or even kill it.
In plant cell walls, crystals of minerals are present in the form of calcium oxalate, carbonate or silica. Druse can be identified as a group of calcium oxalate, silicate or carbonate crystals present in plant cells as a defence against herbivorous animals due to its toxicity.
In plant cells, calcium oxalate crystals occur in the form of a star-shape and are called sphaeraphides. Eg- Colocasia phylloclades, Chenopodium, etc.
Thus, the right option is D.

Note:- The most common constituent of human kidney stones is calcium oxalate crystals in the urine, and calcium oxalate crystal formation is also one of the toxic effects of ethylene glycol poisoning.