The right answer for the question that is being asked and shown above is that: (1) removing metabolic wastes from the body; (2) urea is not soluble in water; (3) simple diffusion across the skin; (4) They both actively pump salt across their gills; (5) <span>They both produce lots of diluted urine."</span>
This illustrates <span>absolute threshold. The correct option among all the options that are given in the question is the second option or option "B".
</span><span>A spot in the middle of the retina that only contains cones is called the fovea. The correct option among all the options that are given in the question is the third option or option "C".</span>
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
For evolution to occur:
There must be genetic variation in a population. This provides variation on which natural selection can act. Then natural selection can act by selecting those species which are better adapted to the environmental conditions. Over time those animals that are best suited to the environment only will survive and reproduce. Those organisms successful genes will be preserved and eventually the gene frequency in the population will change, changing the overall characteristics of a population. This is how evolution occurs.