Answer: W = 6.4x10⁻²¹J
Explanation: <u>Work</u> is the energy transferred to or from an object due to the application of a force along a displacement.
The ion Na is gaining energy to move from a lower potential to a higher one.
For this to happen, the work done is calculated as
in which
W is work in Joules (J)
q is charge in Coulomb (C)
is potential difference in Volts (V)
The ion Na has one positive charge. In coulombs, the charge is
q = 1.6x10⁻¹⁹C
The potential difference in Volts is
= 40x10⁻³ or 4x10⁻²V
Calculating
W = 1.6x10⁻¹⁹. 4x10⁻²
W = 6.4 x 10⁻²¹ J
The work done to move an ion of sodium from the exterior to the interior is 6.4 x 10⁻²¹ J.
Deforestation encourages flooding by allowing water to run off into streams
<u>Explanation</u>:
Deforestation plays vital roles in the flooding. The roots of the Trees prevent sediment runoffs and forests hold more water than farms or grasslands.Firstly the leaves in the trees will capture some amounts of water which will be eventually evaporated. Secondly, some quantity of water is absorbed by the tree's roots. Also,Tree roots hold the soil in place, reducing the movement of sediment that can shrink river channels downstream..
The process of deforestation will lead to dislodging of the topsoil. this makes the topsoil unstable and reduces its capacity to hold down the water
Explanation:
Since lice feed on human blood, severe and chronic infestation can lead to blood loss and iron-deficiency anemia. 5 In addition, an allergic reaction to louse feces or bites may trigger a rash in some individuals.
Answer and Explanation:
The lymph node are the sites for the formation of lymphocytes and monocytes. These are concerned with antibody formation and phagocytosis of foreign materials respectively. In the lymph nodes, bacteria and other harmful materials are removed from lymph.
Answer:
Option C. It is found only in a eukaryotic cell.
Explanation:
Plasma membrane is also called cell membrane. It is found in all cells of living organisms both unicellular and multicellular. It controls the amount of nutrients and wastes entering or leaving a cell. Due to permeability, the substances are easily pass through. Plasma membrane also act as boundary of animal cell.
