Answer:c(cell membrane
Explanation:Quizlet said so
Correct Answer is A. They were able to increase their productivity due to the popularity of tractors.
The best answer is D. He extracted and observed DNA from white blood cells. He is a Swiss physician and a biologist who is known to be the first researcher to identify nucleic acid. He isolated various phosphate-rich chemicals , which he called nuclein or what we know now as nucleic acid, from white blood cells' nuclei which paved the way for him to discover and identify DNA.
The free encyclopedia. A paradoxical reaction or paradoxical effect is an effect of a chemical substance, typically a medical drug, that is opposite to what would usually be expected. An example of a paradoxical reaction is pain caused by a pain relief medication.