Organisms are classified into domains and other groups by similar characteristics. There are three domains: Archaea, Bacteria, and Eukarya. Which of the following characteristics is used to classify organisms into domains? genetic similarities

similarities in habitat

presence or absence of a nucleus

presence or absence of photosynthesis

presence or absence of a nucleus

Explanation:

These classification of organisms into broad domains is based on the present or absence of nucleus in the cell of an organism.

The archaea are prokaryotes and they lack a distinct cellular nuclei.

Bacteria are similar to archaea but bacteria have only one RNA polymerase

Eukarya have true nucleus and membrane bound organelles .

So, the variations in their cells are used to classify organisms into the broad categories

smooth muscle is composed of involuntary muscles found within the walls of organs and structures such as the esophagus, stomach, intestines, and blood vessels. those muscles push materials like food or blood through organs. unlike skeletal muscle, smooth muscle can never be under your control.