Which level of organization consists of groups of cells with similar structures and functions? (More than one may apply.)
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The following is a list of six levels of organization that make up the human body:

(1) Tissue

(2) Cell

(3) Organ

(4) Chemical

(5) Organism

(6) Organ system

The correct order, from the simplest to the most complex level, is

(a) 2, 4, 1, 3, 6, 5

(b) 4, 2, 1, 3, 6, 5

(c) 4, 2, 1, 6, 3, 5

(d) 4, 2, 3, 1, 6, 5

(e) 2, 1, 4, 3, 5, 6

Collections of specialized cells and cell products that perform a relatively limited number of functions are called

(a) Cellular aggregates,

(b) Tissues

(c) Organs

(d) Organ systems

(e) Organisms