First of all, it is a change, not a charge.
Phenotype is physical manifestation of gene(physical), not a change, so it is not phenotype.
Variation is a state of being genetically diverse, but it is not a change, therefore it is not variation.
Genetics is the name of a field, and it is not a change.
Adaption are changes of a population overtime, through natural selection.
It is adaptions
Bird sounds are made in the syrinx, but of course, the air sacs, passageways and the bird's lungs, also contribute to the production of sounds.
When birds start to sing,the 2 passageways between the lung and the syrinx, closes. Then, the sir is squeezed into the air sacs by the chest muscles. Squeezing the air sacs that surrounds the syrinx forces each of the two thin membranes in the syrinx into the 2 passageways between the lung and the syrinx.This process does not allow air to travel through.Afterwhich, muscles around the syrinx contract and tighten one membrane and pulls it out into the passageway (1 of the passageway). Air in that passageway can now move,which passes quickly over the membrane. That fast moving air causes a vibration, thus, sound is produced.
Answer:
The muscle tissue shortens to performs it's function which we know as muscle contraction
A temperature of 30 and a dew point of 30 will give you a relative humidity of 100%, but a temperature of 80 and a dew point of 60 produces a relative humidity of 50%.
The Immune system and Endocrine system work
together to remove these wastes from their cells.
