Video Transcript
Some plants store minerals in the form of blank in their cells to avoid toxicity. (A) Gas, (B) soluble molecules, (C) photochemical compounds, or (D) insoluble crystals.
Mineral ions and water tend to be absorbed from soil into a plant’s roots. The mineral ions dissolve in this water. And they are carried through xylem vessels in this dissolved form to all other parts of the plant that require them. Sometimes, the accumulation of these minerals can have toxic effects on plant cells, resulting in dangerous outcomes for the plant as a whole.
This question is asking us to determine how minerals can be stored in plant cells to avoid such toxic effects. Let’s take a look at an example.
Most plants require a mineral called calcium in fairly considerable amounts, as it plays an important structural role in plant cell walls and cell membranes. However, sometimes, the soil that plants grow in contains too much calcium. This can result in the plant absorbing too much of this particular mineral, which can be toxic when allowed to accumulate.
Some plants, like this potato plant, can respond to this by restricting the accumulation of calcium to their leaves, roots, and tubers. The minerals are stored in these cells’ cytoplasm or vacuoles where they can be converted into an insoluble crystal form. This can help to prevent these potentially toxic compounds from spreading to different parts of the plant and causing harmful effects.
Calcium specifically is usually converted into insoluble crystals of calcium oxalate, which is sometimes called raphides. The plant parts that the insoluble crystals are stored in can be easily shed, removing these toxic substances. Then, the plant can regrow new structures to replace those that were lost.
So now we know the appropriate word to fill in the blank in this question. The correct answer is (D), insoluble crystals.
