Which tool allowed scientists to observe organisms​

Epinephrine is a hormone released from the adrenal gland of the body, most often in a stressful situation. it is known as the "fight-or-flight" hormone. one way that it causes a response in the body is to activate receptors on muscle cells. where are these cellular receptors located? a. on the cell membrane b. in the nucleus c. on the cell wall d. around the mitochondria

Advances in technology have enabled scientists and researchers to better study the evolutionary relationships between species

Explain how the number of similarities between the embryos from early stage to late stage is used as evidence of a common ancestry