Answer:
Hey there!
The correct answer would be a Decrease in myoglobin. Myoglobin contains a large amount of oxygen, and desaturates when muscles move. When you run a marathon, your muscles move and thus you have decreased myoglobin.
Hormones
The endocrine system includes various glands in the body that are responsible for secreting hormones into the bloodstream. Hormones are chemical substances produced by the body that regulate certain functions of cells and organs. Hormones can regulate sleep, sex, growth, stress, huger, metabolism, etc.
Sometimes a single gene can influence many traits is the correct answer
Answer:
When conducting research, scientists use the scientific method to collect measurable, empirical evidence in an experiment related to a hypothesis (often in the form of an if/then statement), the results aiming to support or contradict a theory.
Explanation:
I don't know if it can help you
