The first, second, and fourth statements are correct.
A biological system is a complex network of biologically relevant entities. ... Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. source: google
Intensity is defined to be the power per unit area carried by a wave. Power is the rate at which energy is transferred by the wave. In equation form, intensity I is
I
=
P
A
I
=
P
A
, where P is the power through an area A. The SI unit for I is W/m2. The intensity of a sound wave is related to its amplitude squared by the following relationship:
I
=
(
Δ
p
)
2
2
ρ
v
w
Act as a baseline to compare your data to