Each layer contains the square of the layer number.
<span>So,
Let's figure out :
1 squared = 1 </span>
<span>2 squared = 4 </span>
<span>3 squared = 9 </span>
<span>4 squared = 16 </span>
<span>5 squared = 25
</span>6 squared = 36
<span>Hence,
The total number of oranges in the pile = 1+4+9+16+25+36
= 91 oranges
</span><span>
D. 91</span>
The answer is <span>insect and pest populations decreased.
</span>
DDT (dichlorodiphenyltrichloroethane) was used as an insecticide which is a substance used to kill insects. That resulted in decrease in insect and pest populations. It is a persistent and non-degradable insecticide, but as well organic pollutant readily accumulated to soils and consequently affects organisms.
B - Antibiotics
Antivirals treat viruses, antifungals treat fungi, and OTC treatments are merely symptomatic treatment. Antibiotics typically dissolve the cell wall of bacteria meaning they explode, so they actually kill the bacteria.
Answer: DNA is a long polymer with deoxyriboses and phosphate backbone. Having four different nitrogenous bases: adenine, guanine, cytosine and thymine. RNA is a polymer with a ribose and phosphate backbone. Four different nitrogenous bases: adenine, guanine, cytosine, and uracil.
Explanation: