Minerals for Healthy Growth

This lesson covers:

  1. Why plants need mineral ions such as nitrates and magnesium ions
  2. What happens if plants don't get enough mineral ions 


Illustration showing mineral ions in the soil.

What are mineral ions?


Mineral ions are naturally occurring charged particles that are often found in the soil.


Examples include nitrate ions and magnesium ions.

Diagram showing the anatomy of a flower with petals, stamen, and pistil.

Why do plants need mineral ions?


Plants need certain elements in order to make the compounds required for healthy growth, and they get these elements by absorbing mineral ions.

Diagram showing the absorption of mineral ions by plants to obtain elements like nitrogen, which are converted into useful compounds such as amino acids.

For example, plants absorb nitrates (mineral ions) in order to get nitrogen (element), which they turn into amino acids (useful compound).

What if plants don't get enough mineral ions?


If plants don't get enough of a particular element then they may develop a mineral deficiency. This will lead to specific symptoms, depending on which element they are deficient in. 

How do plants absorb mineral ions?

Diagram showing active transport of mineral ions in plant roots

As mineral ions are dissolved in the soil, plants can absorb them via their roots. This requires active transport because there is a higher concentration of mineral ions in the root hair cells than there is in the surrounding soil.

Diagram showing the effect of magnesium deficiency on plant leaves, leading to yellowing.

Magnesium ions


Magnesium is required to produce chlorophyll, which is the green pigment in chloroplasts that absorbs sunlight for photosynthesis. 


If plants don't get enough magnesium, they can't make enough chlorophyll and so their leaves will turn yellow. The growth of the plant may also be stunted as they won't be able to photosynthesise to produce sugars. 

Illustration showing healthy plant growth with sufficient nitrates and stunted growth with yellow leaves due to nitrate deficiency.

Nitrates


Nitrates contain nitrogen which is required to make amino acids and hence proteins. 


Proteins are needed for cell growth, so if a plant doesn't get enough nitrates it won't grow properly. This leads to stunted growth and yellow leaves. 

Which mineral ions are needed for chlorophyll in plants?

Carbonate ions

Magnesium ions

Phosphate ions

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Why do plants need nitrate ions?

To produce starch 

To produce lipids

To produce amino acids 

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Illustration showing the process of plants absorbing mineral ions from the soil.

How do plants absorb mineral ions?

Diffusion

Active transport

Osmosis 

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What is a mineral ion deficiency?

When plants don't get enough sunlight

When plants don't get enough water

When plants don't get enough mineral ions

When plants get too many mineral ions

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Which cells in a plant absorb mineral ions?

Root hair cells

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Explain why plants need nitrate ions, and what will happen if they don't get enough.

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Illustration showing a symbol for magnesium ion deficiency leading to a question mark.

What is the main symptom of magnesium ion deficiency?

Purple leaves

Yellow leaves

Patches on leaves

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