Answer:
Low - The generation of nitrates (NO 3-) requires oxygen, so the oxygen levels will be low
Explanation:
Nitrates are formed when the ammonia react with oxygen present in water. The oxygen which react with ammonia is not the oxygen of water molecule, it is the dissolved oxygen. This oxygen is used by aquatic animals for breathing. If nitrates are formed so the concentration of dissolved oxygen will be lowered which causes suffocation and bad impact on marine organisms and the whole ecosystem will be disturbed.
Answer: The frequency of brown beetles is 0.32.
Explanation: The frequency of A1 allele is 0.8. As p+q=1, or the sum of dominant and recessive frequencies equals 1 or 100%:
1 - 0.8 = 0.2
In Hardy-Weinberg principle,

2pq represents the frequency of heterozygote individuals, so:
genotype A1A2 = 2*0.8*0.2 = 0.32.
Thus, the frequency of brown beetles (A1A2) in the population is 0.32.
"From the dog" is the prepositional phrase since it begins with the preposition "from" followed by the noun phrase "the dog" .
Mechanical waves cannot move without a medium