The human heart, composed of specialized muscle cells, beats to a specific rhythm. the heart cell rhythm partly depends on the opening and closing of series of gateways within the cell membrane, called ion channels. some channels let certain ions flow out, others let different ions flow in. the same membrane system is at work in other cells, to regulate what stays and what leaves the cell.
this cell membrane gateway system is specifically called the
a)
sodium-chlorine pump.
b)
hydrogen-oxygen pump.
eliminate
c)
sodium-potassium pump.
d)
calcium-potassium pump.

Based on the evidence in the excerpt above, describe in your own words what it would have been like for a person to enter a meat processing plant in the united states

On a recent expedition to a remote region of northern canada, scientists uncovered skeletal remains from about 100,000 years ago. surprisingly, all the skeletal remains, which included many species from differing biological families and spanned about two thousand years, showed evidence of experiencing temperatures in excess of 1000 degrees fahrenheit (or 538 degrees celsius). which of the following, if true, best explains the apparent paradox between the cold environment and the evidence of the bones experiencing hot temperatures? (a) chemical changes that naturally occur during the process of decay in only one north canadian species produce the same evidence of the species' skeletons being exposed to hot temperatures as the expedition scientists found. (b) a little over 103,000 years ago, a large fire is known to have occurred in northern canada. (c) strong evidence exists that as early as 70,000 years ago, homo sapiens around the world relied heavily on fire to cook animals. (d) in the same expedition and in roughly the same layer of excavation, scientists found rudimentary wood cutting and hunting tools used by early humans.

Which of the following types of rock would most likely contain a fossil? slate granite lava rock limestone