Question

Living systems are organized in levels according to their structures and functions. _____-> tissues-> organs -> organ systems-> organisms -> ecosystems Which word is missing from the organized chart above A. Cells B. Water C. Bacteria D. Protons

Answer 1

Answer:

The answer to your question is the letter A. Cells

Explanation:

A. Cells    this choice is the correct answer because a tissue is many cells interconnected that perform a similar function.

B. Water  this choice is incorrect because do not form part of this level of organization of living things.

C. Bacteria is a living thing, a prokaryotic cell, many bacteria do not form tissues, so this choice is incorrect.

D. Protons are a level of organization that comes before cells and molecules, not before tissues, so this choice is incorrect.