What does an electrocardiogram measure? a) sound waves created by the closing of heart valves b) the volume of blood moving through the heart chambers c) the force of muscle contraction in the heart chambers d) action potentials moving through the heart muscle

The table below shows data for a population of fish in a pond. fish body color # of fins scales? tail shape a silver 4 yes fan b pink 4 yes flat c black 4 yes fan d orange 4 yes flat e orange 4 yes fan f silver 4 yes flat which of the above characteristics would be most in developing a classification system for the fish? a. body color and tail shape b. presence of scales and tail shape c. body color and number of fins d. number of fins and presence of scales

Which of the following is a feature of all cells? o a. all cells have a nucleus. o b. all cells have dna for at least part of their life cycle. het . o c. all cells are spheres. o d. all cells have a rigid cell wall.

Organisms may contain up to five levels of organization within their bodies. which level of organization is shown by the liver? a. tissue b. organ c. organism d. organ system