Smooth muscles depolarize as a result of a transmembrane current of Calcium ions. When an action potential depolarizes the muscle cell membrane, it also travels into the body of the cell via the t-tubules. Unlike skeletal muscle, smooth muscle is dependent in two sources of calcium in order to intiate contraction. These two sources are calcium sequestered in the S.R. of the smooth muscle cell.
This question is incomplete. The options are:
a. Oligocene b. Eocenec. Miocene<span>d. Pleistocene
</span>Option b is correct. This relates to the Paleocene-Eocene Thermal Maximum (PETM) which occured around 56 million years ago and was similar to modern-day climate change. Warming of more than 5 degrees Celcius occured over<span> 15-20 thousand years because of input of more than 2000 gigatons of carbon into the atmosphere. The PETM resulted in mass deep ocean extinctions and mass terrestrial and shallow ocean diversification.</span>
1.) similar fossils were found on different continents.
2.)the continents seemed to fit together; they were like a spread apart puzzle.
3.)geographical features and mountain ranges lined up with the same rock composition
4.)glacier grooves in rocks led him to trace them out to where they started
:)
Modern humans have been the only species of homo, so true .
Animalia are heterotrophs while plantae are autotrophs
Hope it helps.
