Which of the following are techniques besides molecular clocks used by scientist to calculate the rate at which a stretch of DNA changes? (Choose all that apply) •comparison of human behaviors
•carbon dating of fossils
•comparison of blood proteins
•comparison of homologous structures

Comparison of homologous structures and carbon dating of fossils. (B and D)

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.