The crossing over mechanism of genetic variation results from the exchange of gene segments between non sister chromatids. The correct answer is A.
Answer:
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Explanation:
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The correct answer is option A. They either match up with a receptor molecule on the surface of the cell or enter the cell through the membrane.
The intercellular signals are the signals, which transfer the signals from one cell to the another and the intracellular signals are those signals, which carries message within the cell.
The intercellular signals may or may not be transferred through the gap junctions. The chemical signals are one of the type of the cell signals. The chemical signalling molecules generally have a receptor on the cells, where these molecules can bind and can be cause the activation of the cell. The chemical signals can also enter into the cells through active transport and facilitated diffusion. So, these type of transports does not go through the Gap junction.
The food ingredient that is important for brain development is GLUCOSE.
Glucose is the only type of nutrient that the brain can use to carry out its biochemical activities. The brain usually use about 20% of the glucose content that is available in the blood. Absolute lack of glucose for brain use can cause one to go into coma.<span />