<em>C. Binding to the operator.</em>
Explanation:
When the repressor starts binding to the operator, it can not transcribe, or make mRNA. This makes it so the RNA polymerase can't go onto the promoter and bind to it, which is a crucial part in making mRNA. The operator functions by making sure the certain DNA gets made, so it is very important. The lac repressor will turn off the expression of the lac genes by binding to the operator.
Answer:
The amount of the solute is the quantity that would be equal between two solutions that are isotonic.
Explanation:
Tonicity can be described as the measure of osmotic pressure among solutions.
If the amount of solutes that is present in a solution is equal to the amount of solute that is present in another solution, then the two solutions would be considered as isotonic. No transfer of solutes will take place in such solutions.
Any rise or loss of solutes in either of the solutions will result in the transfer of solutes among the solutions and the solutions will no longer remain isotonic.
The major purpose of the cell membrane is to regulate the types of substances that enter the cells and leave the cell, thus, it is a semi permeable structure.
The structure of the cell membrane help the cell in regulating the amount of the water inside the cell because, when the optimum amount of water is inside the cell, the membrane will not allow the pasage of water molecules into the cell again.
And in a situation, where the concentration of substance inside the cell is above the normal concentration, the cell membrane will allow the required amount of water to flow into the cell in order to reduce the concentration.
Also, the phospholipid bilayers that are found in the cell membrane help to regulate water homeostasis of the cell by using its hydrophobic tail to repel water molecules and thus keep them out or inside of the cells.
Answer:
<h2>EGFR will activate other proteins without dimerization, causing uncontrolled cell growth.</h2>
Explanation:
EGFR gene
:
Epidermal growth factor receptor,
-which spans the cell membrane so that one end of the protein remains inside the cell and the other end located outer surface of the cell. This causes receptor to attach ligands, and to receive signals ,by which cell respond to its environment. Epidermal growth factor receptor binds to many different type of receptors. The binding of a ligand to receptor allows the receptor to attach to another nearby epidermal growth factor receptor protein (dimerize), activating the receptor complex. As a result, signaling pathways within the cell are triggered that promote cell growth and division and cell survival. If there is abnormlty in the expression of EGFR gene , then the cell show uncontrolled growth.
Explanation:
The information stored in the DNA is essential for life. If a cell dies the body must replace that cell. The only way to replace the cells is to first copy the information that the cell contained. There is a complex system of proteins and enzymes that unravel the DNA double helix so that the DNA can be copied.
If a single cell dies it can be replaced through mitosis. The two daughter cells are identical to the original cell whose DNA was copied. This system works well with single cell and simple organisms.
