In the given figure,what does $A$ indicate?

Select the correct statements regarding cell membrane in eukaryotic cell.
$A$. Membrane of human $RBCs$ has approximately $52\%$ protein.
$B$. Major phospholipids are arranged in a bilayer.
$C$. Extensions of the plasma membrane into the cell form mesosomes.
$D$. Tails towards the inner part of lipids are hydrophobic and thus protected from aqueous medium.
$E$. Glycocalyx is present on the outer surface of the plasma membrane.
Choose the correct answer from the options given below:

$A$ boy is studying the transport of a certain type of molecule into a cell. He finds that the transport slows down when the cells are poisoned with a chemical that inhibits energy production. Under normal circumstances,the molecules studied by the boy are probably transported by

Who proposed the most widely accepted model of the plasma membrane?

Who proposed the $Fluid$ $Mosaic$ $Model$ for the cell membrane?

Water channels are possessed by a membrane to facilitate the movement of hydrophilic substances. These channels are made up of