Answer: The term that matches the definition given is organelle.
Step-by-step explanation:
Organelles are membrane-bound parts of a cell that act like tiny organs, each performing a specific function. They are found in eukaryotic cells, which are cells that have a defined nucleus and membrane-bound organelles. Examples of organelles include the mitochondria, which produce energy for the cell, the ribosomes, which are responsible for protein synthesis, and the endoplasmic reticulum, which is involved in the synthesis and transport of proteins and lipids.
Centrioles are organelles found in eukaryotic cells that are involved in cell division. They are not membrane-bound and do not have a specific function within the cell like organelles do.
Eukaryotes are a group of organisms that are characterized by the presence of eukaryotic cells, which have a defined nucleus and membrane-bound organelles.
The nucleus is a membrane-bound organelle found in eukaryotic cells that contains the cell's genetic material. It is not considered to be a tiny organ like other organelles, but rather a central part of the cell that plays a key role in the regulation of cell function. So the correct answer is A. organelle.