Gene (DNA) expression would be B
Most of the water is salt water
You can classify them in what phase they are in: solid, liquid, gas
You can classify them in Sizes
You can classify them by the number of moons they have
You can classify them by distance from the sun
You can classify them all as heliocentric or orbiting/circling around the sun
You can classify them by color
The right answer is D.
The density of a given population is calculated by dividing the number of inhabitants by the area expressed in km² (or in hectares).
Number of inhabitants ÷ area (in km²) = number of inhabitants / km²
A = 125000 organism/ 2.5 m2 = 50,000 organisms / m2
B = 13000 organisms / m2
C = 37500 organisms / m2
D = 200000 organisms / m2
