A biologist began studying a population of bullfrogs. In 1998, she found that
most of the male frogs croaked, but some did not. A bat species known to
prey on male frogs migrated to the area in 2005. The biologist returned to the
area in 2008 and repeated population counts of male frogs. The table shows her data.

cancer   is   essentially   uncontrolled   mitosis   of specialized cells

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.

you know that this symptom is misleading and quite often is related to: heart attack

a heart attack is a condition that occurs when the blood flow that transports oxygen to the heart muscle is damaged or cut off completely. the coronary arteries that supply the heart muscle with blood flow can be blocked by the accumulation of plaque. also, when the plaque within the heart artery breaks, it creates blood clot that can also hinder the blood flow. men that are over 45years of age and women that are over 55years of age are at risk of having a heart attack. the symptoms of a heart attack include chest discomfort, chest pain, coughing, and shortness of breath.