What observation led researchers to propose that chloroplasts evolved from cyanobacteria?

As global warming continues the ocean absorbs more of the earth's heat what term describes the ocean as a storage location for heat a) heat binb) heat sinkc) heat storaged) heat vent( answer this for me)

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

Idont understand by supporting the plant and holding the leaves up to the light. question 3 options: tap or fibrous root flower petals herbaceous or wood stems leaves with stomata