Answer the following question given this paragraph: Water potential is a measure of the potential energy in water. Plant physiologists are not interested in the energy in any one particular aqueous system, but are very interested in water movement between two systems. In practical terms, therefore, water potential is the difference in potential energy between a given water sample and pure water (at atmospheric pressure and ambient temperature). Water potential is denoted by the Greek letter (psi) and is expressed in units of pressure (pressure is a form of energy) called megapascals (MPa). The potential of pure water (wpure H2O) is, by convenience of definition, designated a value of zero (even though pure water contains plenty of potential energy, that energy is ignored). Water potential values for the water in a plant root, stem, or leaf are therefore expressed relative to wpure H2O. The water potential in plant solutions is influenced by solute concentration, pressure, gravity, and factors called matrix effects. Water potential can be broken down into its individual components using the following equation:. Q: What is the measure of water potential? Choices: - trials - fluctuations - spores - megapascals A:
megapascals

Answer the following question given this paragraph: There are a variety of types of movable joints, which are illustrated in Figure below . The joints are classified by how they move. For example, a ball-and-socket joint , such as the shoulder, has the greatest range of motion, allowing movement in several directions. Other movable joints, including hinge joints such as the knee, allow less movement. Q: Give an example of a ball-and-socket joint, which has the greatest range of motion, allowing movement in several directions. Choices: - pulley - lever - monkey wrench - shoulder A:
shoulder

Answer the following question given this paragraph: About 85 percent of teens develop acne, like the boy in Figure below . Acne is a condition in which pimples form on the skin. It is caused by a bacterial infection. It happens when the sebaceous glands secrete too much sebum. The excess oil provides a good place for bacteria to grow. Keeping the skin clean helps prevent acne. Over-the-counter products or prescription drugs may be needed if the problem is serious or doesn't clear up on its own. Q: What is the condition called where pimples form on the skin? Choices: - blushing - cramping - dermatitis - acne A:
acne