Lead released into the environment makes its way into the air, soils, and water and can remain in the environment as dust, indefinitely. the epa and the centers for disease control and prevention (cdc) agree that there is no known safe level of lead in a child's blood. lead is harmful to health of all age groups, but especially children. the u. s. has banned leaded gas and leaded paints, yet this toxin is still found in our drinking water. what is the main cause of lead inner drinking water?

Liquefaction was one reason the kobe wharfs were destroyed and other areas nearby. what is liquefaction? a. it is when conditions in the soil send the seismic wave out to the mountains and bounce back b. it is when conditions in the soil change to vigorous p-wave shaking when the surface waves pass by c. it referes to the fact that when an earthquake occurs wet and soft soil will vibrate more vigorously then solid rocky soil strangely in kobe some streets had very bad damage but the next street over had far less damage. what caused this? a. the waves passed through the city hit the mountains and returned back to the city. at some points the incoming and outgoing waves amplified their strength b. the mountains also had a quake and sent waves into the city c. waves hit the moutains and took longer to return

Rarefaction is used for which of the following? a. creating a representative sample b. studying how disease impacts populations c. rediscovering species thought to be instinct d. determining which sea creatures live in an area

Choose the incorrect statement (a) the motor end plate membrane is only capable of generating graded potentials, but it is contiguous with the skeletal muscle sarcolemma, which can generate action potentials. (b) propagation of an action potential through the t-tubules into the sarcoplasmic reticulum triggers the release of ca++ into the cytoplasm of a skeletal muscle fiber. (c) the generation of suprathreshold endplate potentials in multiple muscle fibers could be due to the increased frequency of action potential generation at the axon hillock of a single motor neuron. (d) a greater amount of ach would be found in the presynaptic vesicles of a motor unit that fired several action potentials after exposure to botulinum toxin, than in a motor unit that fired several action potentials after exposure to the venom of the krait snake (which contains α-bungarotoxin).