The Diagram shows structures that form the surface of the trachea. Which level of organisation is the structure labelled S ?
A. Cell
B. Organ
C. Organ system
D. Tissue

Approximately percent of the energy created by cell metabolism is used by the body to carry on its normal functions, such as respiration, digestion, reproduction, muscular movement, circulation, and cellular regrowth.

Which of the following is an abiotic factor in an ecosystem? a. bacteriab. airc. niched. grass(abiotic=non-living) me !

List do people affect the environment