-ploid

The combining form –ploid is used like a suffix meaning “having chromosome sets.” It is occasionally used in scientific terms, especially in biology.

The form –ploid is extracted from the endings of words such as haploid, which means “pertaining to a single set of chromosomes.” The word haploid itself comes from the combination of two forms: hapl–, meaning “single”, and –oid, meaning “resembling” or “like.”

A scientific term that uses the form –ploid is polyploid, “having a chromosome number that is more than double the basic or haploid number.”

The poly– part of the word may look familiar; it means “many,” from Greek polýs. The –ploid part of the word means “having chromosome sets.” Polyploid literally translates to “having many chromosome sets.”

What are some words that use the combining form –ploid?

• diploid
• hexaploid
• hyperploid
• hypoploid
• pentaploid

What are some other forms that –ploid may be commonly confused with?

• -plegia
• -pod
• -polis

The combining form penta– means “five.” With this in mind, what does pentaploid mean?