The correct answer is A.
The cell membrane consists of a phospholipid bilayer with embedded proteins. Sometimes molecules are just too big to easily flow across the plasma membrane or dissolve in the water so that they can be filtered through the cell membrane. In these cases , the cells must put out a little energy to help get molecules in and out of the cell.
The proteins embedded in the plasma membrane form channels through which other molecules can pass. Some proteins act as carriers, that is they are 'paid" in energy to let a molecule attach to itself and then transport that molecule inside the cell. This is called active transport.
Answer:
Yes.
Explanation:
Reactors use uranium for nuclear fuel. The uranium is processed into small ceramic pellets and stacked together onto sealed metal tubes called fuel rods. The heat created by fission turns the water into steam.
Answer:
0.358g
Explanation:
Density of Helium = 0.179g/L
ρ=m/v
m=ρv
when the volume was 2L
m1= 0.179*2
m1=0.358g
when the volume increased to 4L
m2= 0.179*4
m2=0.716g
gram of helium added = 0.716g-0.358g
=0.358g
