A fully functioning enzyme molecule is fold into a complex
three-dimensional shape and this structure determines the specific type of
molecules it interacts with during a reaction. Each functioning enzyme molecule
has a particular structure to bind <span>with a high degree of specificity to one or a few molecules
and to carry out its function. Therefore, cellular function is directly
associated to its structures.</span>
Pulmonary ventilation comprises two major steps: inspiration and expiration. Inspiration is the process that causes air to enter the lungs, and expiration is the process that causes air to leave the lungs. A respiratory cycle is one sequence of inspiration and expiration
While both show the process of natural selection, vestigial structures no longer have a working function, but are still present in an organism. An example of this in humans is the appendix. To humans, it doesn't necessarily serve any function, but it is just there as part of the human body.
On the other hand, analogous structures are similar structures in different species that perform the same function. We can think of it as wings on a moth, bird, and a fly. While the three do not share a common ancestor, the structure of the wings are said to be analogous.
If there are not to many leaves on the trees not too many birds will build a nest in it because the tree is not shaded and the birds will get hot and will not want the small birds to over heat and die.
