During the woman's menstrual period.
ERGONOMIC keyboards such as "Microsoft Natural Keyboard" can help prevent injuries from using the keyboard for long periods of time. Posture related injuries result from long use of laptops and computers. The ergonomic keyboards are easily adjustable by adjusting height in a particular angle.
Both "depends upon the binding of that substance to a specific site on the membrane protein" and "depends upon movement of proteins from one side of the membrane to the other" are correct.
The saturation effect prevents statement 2 from being true.
Yes, this is true, and it is actually one of the organisms driving evolution! Some organisms develop mutations that are actually beneficial (better eye-sight, for example) and they're more likely to pass those to their children that individuals without those mutations!
