Scientists Say: Spore

Spore (noun, “SPOR”)

A spore is a type of cell that certain fungi, plants, algae and bacteria use to reproduce.

Like a seed, a spore is a tough little speck that can grow into a new life form under the right conditions. But unlike a seed, a spore is usually a single cell that can only be seen with a microscope.

Fungi rely heavily on spores. Consider the common puffball mushroom (Lycoperdon perlatum). As these ball-shaped mushrooms grow, they swell like little balloons. Eventually, they pop open. A hole appears at the top that releases smokelike poofs of spores when jostled.

Some plants also use spores. Ferns, for instance, typically produce spores under their leaves. These spores appear as little dirtlike clumps. Mosses typically grow long stalks with spore-filled capsules on the ends.

Resiliency is a key trait of spores. These cells can endure extreme heat and cold. They can also withstand long dry periods and even intense, DNA-damaging radiation. Then, when conditions are more favorable, they can grow up into new life forms.

Spores use a few tricks to manage this, such as wearing a protective coat. But their sneakiest trick lies in their ability to go dormant and “play dead.”

In this state, a spore is generally not carrying out much chemistry, which saves a lot of energy. In their dormant state, spores can also get by without much water. This not only helps spores survive dry conditions. It also helps them endure extreme temperatures. That’s because when the water in a cell freezes or nears boiling, it can warp the shape of important molecules, such as proteins. Dried out, dormant spores avoid those risks.

Bacterial spores — called endospores — may be nature’s hardiest cells. Some have been known to grow after hundreds or thousands of years of dormancy.

In a sentence

Bacterial spores withstand extreme conditions, including the vacuum of space.

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