Answer:
active transport, like Na + ions leaving the cell
Explanation:
The active transport requires an energy expenditure to transport the molecule from one side of the membrane to the other, but the active transport is the only one that can transport molecules against a concentration gradient, just as the diffusion facilitated the active transport is limited by the number of transport proteins present.
Two major categories of active, primary and secondary transport are of interest. The primary active transport uses energy (generally obtained from ATP hydrolysis), at the level of the same membrane protein producing a conformational change that results in the transport of a molecule through the protein.
The best known example is the Na + / K + pump. The Na + / K + pump performs a countertransport ("antyport") transports K + into the cell and Na + outside it, at the same time, spending on the ATP process.
The secondary active transport uses energy to establish a gradient across the cell membrane, and then uses that gradient to transport a molecule of interest against its concentration gradient.
The answer is B because:
Cell walls are made of cellulose and proteins (hence II).
Animal cells don't have cell walls (only cell membrane) but plant cells do so IV
They must be semipermeable since materials for example carbon dioxide and water for photosynthesis have to go into the cell <em>some</em> way.
p = m / V (Density = Mass / Volume)
p = m / (w * l * h) (Density = Mass / [Width * length * height]) (V = w * l * h)
p = 120 / (5 * 4 * 3) (Mass = 120g [Given] w=5 l=4 h=3 [Given])
p = 120 / 60
p = 2 g/cm^3
Answer is B (2)
One of the best examples would be Archaea
