Tom and jesse decided to perform an experiment to see what exercise does to blood pressure. they decided to test their friend john. below is their procedure.1. take test subject's resting blood pressure.2. have test subject do either sit ups, push ups, or sprint for one minute.3. take test subject's blood pressure. tom and jesse run the same tests on john every day for one week. running the same test, for one week, is an example ofa) validity. b) a control. c) repetition. d) replication.

Mitochondria is the cell organelle that produced the energy that is needed in the body system in form of atp, that is why it is called the power house of the cell. energy is needed by the living organisms to carry out the activities which sustain life.  if the mitochondria is destroyed atp will not be produced. if the mitochondria is destroyed, energy production will stop and the affected living organism will not have the energy to carry out the necessary life processes; this will lead to the death of the organism.

Molecules called lipids have long hydrocarbon chains that determine the way they act. they can be fats, oils, or hormones, and even exist in our cell membranes