What is the answer of “ an animalcule known today as single-cell organism”

Animalcule is an ancient term for all unicellular organisms, whether prokaryotes —such as bacteria—or eukaryotes, such as amoebas.

Explanation:

Animalcule was the name of what we know today as microorganisms, a term used by van Leeuwenhoek in his observations under the microscope.

Single-cell organisms are those that —unlike multicellular organisms— do not need to join together to form tissues, but are simple organisms that can fulfill their functions independently. Single-cell organisms include:

The term animalcule previously included all these unicellular organisms, which have now been defined and classified, being called microorganisms or single-cell organisms.