Which of the following is INCORRECTLY spelled.

The word Protien is incorrectly spelled. The correct spelling is Protein.

Here are the words and their correct spellings:

• Protein is a type of biological molecule that is essential for life.
• Runner is a person who runs for sport or exercise.
• Rectangular means having four sides with four right angles.
• Kennel is a small building or enclosure for keeping dogs.