Life processes of the human body are maintained at several levels of structural organization. These include the chemical, cellular, tissue, organ, organ system, and the organism level. Higher levels of organization are built from lower levels. Therefore, molecules combine to form cells, cells combine to form tissues, tissues combine to form organs, organs combine to form organ systems, and organ systems combine to form organisms.
cell
smallest independently functioning unit of all organisms; in animals, a cell contains cytoplasm, composed of fluid and organelles
organ
functionally distinct structure composed of two or more types of tissues
organ system
group of organs that work together to carry out a particular function
organism
living being that has a cellular structure and that can independently perform all physiologic functions necessary for life
tissue
group of similar or closely related cells that act together to perform a specific function
1. The smallest independently functioning unit of an organism is a(n) ________.
A) cell
B) molecule
C) organ
D) tissue
A
2. A collection of similar tissues that performs a specific function is an ________.
A) organ
B) organelle
C) organism
D) organ system
A
3. The body system responsible for structural support and movement is the ________.
A) cardiovascular system
B) endocrine system
C) muscular system
D) skeletal system
D
1. Name the six levels of organization of the human body.
Chemical, cellular, tissue, organ, organ system, organism.
2. The female ovaries and the male testes are a part of which body system? Can these organs be members of more than one organ system? Why or why not?
The female ovaries and the male testes are parts of the reproductive system. But they also secrete hormones, as does the endocrine system, therefore ovaries and testes function within both the endocrine and reproductive systems.