Cardiac muscle and some types of smooth muscle have the ability to contract without any external stimuli. True or False

True.

Explanation:

Cardiac muscle and some types of smooth muscle have the ability to contract without any external stimuli.

These muscles are called involuntary muscles.

Involuntary muscle are named so because,these muscles are independent of voluntary control and are controlled by our autonomic nervous system.

These are also known as white or smooth muscle.

Examples, muscles of heart, muscles of alimentary canal etc.