<span>Explanation: Oxygen is the more electro-negative of the atoms in the water molecule, so it tends to pull the 'shared' electron more to itself. Thus, the oxygen atom has a greater time-share of all electrons, and therefore the hydrogen atoms are more positive for a partial lack of electrons</span>
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sodium-potassium pump. n. The enzyme-based mechanism that maintains correct cellular concentrations of sodium and potassium ions by removing excess ions from inside a cell and replacing them with ions from outside the cell.
The correct answers are as follows:
1. A.
There are basically two types of succession, they are primary and secondary succession. Primary succession refers to the type of succession that occurs in new and bare areas where the soil present is unable to sustain the growth of plants. An example of primary succession area is an area with sand dunes that is freshly formed. Primary succession usually occur over a long period of time. Secondary succession is a type of succession that occur on a land which was disturbed by hazardous events such as fire outbreak, flood, etc. Secondary succession occurs much faster than the primary succession.
2. D
There are two types of factors that affect any particular ecosystem, these are abiotic and biotic factors. The abiotic factors refers to non living factors such as temperature, relative humidity, rainfall, etc. while the biotic factors refer to the living factors. Looking at the options given above, one will see that only option D has living factor, which is predators. All other options have abiotic factors.
A cell membrane protects a cell from it's surroundings. The cell membrane controls the movement of substances from the outside and inside of cells and organelles.