When we breathe, our respiratory system takes up oxygen and carbon dioxide or other useless gases go out . The oxygen combines with the haemoglobin in the blood of the circulatory system . This is transferred to all the cells of our body to get energy.
Bruh you literally just gotta look up the word and give an example
Evolution would least likely be a cause of natural selection.
Natural selection has to do with the survival of the fittest. Therefore, adaptation, variation, and overpopulation all have an impact on natural selection - those who do not adapt to their new surroundings due to overpopulation or those whose bodies have not modified enough will not survive.
