The is the lowest level of life's structural hierarchy.
a) cell
b) ecosystem
c) species

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction. this is an example of speciation.

Where does the information about where each transcription factor binds originate?

How do all types of diffusion/passive transport actually ‘work’ without using even the smallest amount of cellular energy?