The short answer is that cells respond to the chemical environment in which they find themselves. The cells around them, the specific conditions, and feedback from the environment all create specific chemical cues that inform the cells to which genes should be expressed, and in what amounts. Chemicals include hormones, cytokines, general signaling molecules, such as cAMP, etc.
i literally hopped on google for this, lol.
i hope this helps though. :)
I believe the answer is tertiary
In a food web there is a hierarchy, if any one of the parts of a food web is changed it can effect the parts above that may consume it, or the parts below that it may consume. Since the food web relies on balance and a hierarchy, if something changes it could disrupt the balance and flow of energy in the food web.
The correct answer is "crossing over."
Cellular growth takes place under interphase, specifically under G1 phase of interphase wherein there is increase in cell proteins and structure. Duplication of chromosomes (or DNA synthesis) takes place under interphase, specifically under the S phase of interphase. In the S phase, there is also duplication of organelles. Crossing over takes place under prophase I of meiosis.