Answer:
The correct answer is C
Explanation:
I took the test on edg2020
The plasma membrane of axon is called axolemma. The potassium and sodium leak channels leak the sodium and potassium ions inside the cell respectively. The leak channels provide the constant movement of ions across the membrane. Potassium and sodium ions are positively charged, thus entry of positively charged ions inside the cell makes the cell more positively charged than the environment outside the cell. The environment outside the cell becomes more negatively charged. This leads in the negative membrane potential of axolemma.
The correct answer is (B) Photosynthesis and diffusion from the air
Dissolved oxygen enters the water from photosynthesis and through air. The The aeration of water can be caused by wind. From the air oxygen diffuse into the water and gets mixed in the it through circulation. The oxygen is also produced as a waste product of photosynthesis from blue-green algae, phytoplankton, etc which is added in water.
Because the fatty acid chains are saturated and unsaturated hydrocarbons, it implies that the fatty acid chains of a phospholipid is not attracted to water hence why they are turned inwards towards each other and away from aqueous medium. This implies that the interior of the membrane is HYDROPHOBIC (water-fearing/water-repelling).
