Answer: B
Explanation:
Ammonia is so toxic that it can be transported and excreted only in large volumes of very dilute solution. As a result most terrestrial animals simply don't have access to sufficient water to routine excrete ammonia.
The main advantage of urea is its very low toxicity. Animals can transport urea in the circulatory system and store it safely in high concentrations. Also much less water is loss when a given quantity of nitrogen is excreted in a concentrated solution of urea than would be in a dilute solution of ammonia.
Answer: A storm or tornado
Explanation:
A bacterial promoter sequence must be included. The coding exons control the actual production of the protein that the gene codes for; meanwhile, the promoter sequence serves to initiate transcription of the specific genes. Promoters are included upstream of the DNA molecule at the start site of the gene.
