ANATOMY

Detailed explanation-1: -When two or more organs perform a common function by their physical and/or chemical interaction, they together form organ system. Many organ systems are then organised and form an organism. So, the correct order is: Cells-Tissues-Organs-Organ systems-Organism.

Detailed explanation-2: -The organization of life is ordered as following from the smallest to largest; cells, tissues, organs, organ systems, organism. Cells are the smallest unit that carries out basic activities. Tissue is a group of cells that work together to carry out certain functions.

Detailed explanation-3: -The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.

Detailed explanation-4: -Therefore, we can conclude that the order of these structures, from smallest to largest, is cells → tissues → organs → organ systems. An organism is one living thing. An organism may be made of one cell, in which case they are referred to as a unicellular organism.

Detailed explanation-5: -Cells → Tissue → Organ → Organ system → Organism.