Spelling.School · How to spell

How to spell a

A is spelled A.

What it means: Used before a singular noun to mean one.

In a sentence: A cat sat on the mat. ▶

Same family: nucleotide, DNA, base-pair, genetic, adenosine. If you can spell one, the shared part carries to the others.

Where it comes from: In genetics, the lowercase letter a is used as a simple symbol for adenine, one of the four DNA bases. The name adenine itself comes from the Greek word “aden,” meaning “gland,” because it was first isolated from animal glands.

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Words like this

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