<span>The answer is A. This is because the P53 gene is involved in a cell cycle regulation and is thought to hold the cell in a particular phase until DNA defects are repaired. </span>
None of the provided options are reasonable. <span>comparing nutrient concentrations between the photic zone and the benthic zone can not tell you whether differences in concentrations between the photic and benthic zone are due to uptake by phytoplankton or because nutrients are sinking to the sea bottom and ocean stratification is preventing mixing. The approach of c</span><span>ontrasting nutrient uptake by autotrophs at different locations under different temperatures would not provide useful information on limiting nutrients. but rather uptake rates at different temperatures. It is likely that e</span>xperimentally enriching some areas of the ocean and compare their productivity to that of untreated areas can provide an indication of limiting nutrients, but this is not advisable, as it would have to be done on a large scale, and one cannot be sure of the ecological consequences. Also, because it would not be a controlled experiment, other factors could create 'noise' in the data. The last option, <span>observe antarctic ocean productivity from year to year to see if it changes, also does not help, as there is no correlation between nutrient concentrations using this approach. The best approaches would be either the last approach, but with the additional monitoring of nutrient concentrations, or under a controlled laboratory experiment.</span>
Answer:
the nervous system send signals from one cell to another or from one part of the body to another part of the body.
Explanation:
I know they carry diseases which can harm or kill the animal it is attached to. These diseases can taint the meat of the animal so it wouldn't be wise to eat it which stinks if the animal is bread for eating. They can also irritate the skin and cause rashes, or even eat the flesh of the animal away.