Question

1. the smallest unit of biological structure that meets the functional requirements of \living\ is the ______.

a. organ
b. organelle
c. cell
d. macromolecule

Explanation:

To determine the smallest unit of biological structure that is "living", we analyze each option:

• Option a: An organ is a group of tissues working together, not the smallest living unit.
• Option b: An organelle is a part of a cell, not a self - sufficient living unit on its own.
• Option c: A cell is the basic structural and functional unit of life. It can perform all the necessary functions to be considered living, such as metabolism, reproduction (in single - celled organisms), etc.
• Option d: A macromolecule is a large molecule like DNA or protein, and it does not have the properties of a living entity.

Answer:

c. cell