What does Rob mean when he says some tropical lakes do not "cycle

In addition to seeds, which of the following characteristics are unique to the seed-producing plants? a) sporopollenin b) lignin present in cell walls c) pollen d) use of air currents as a dispersal agent e) megaphylls

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

Drag each tile to the correct box. arrange the phases of mitosis in the correct order. 1 (condensation of chromosomes) 2 (separation of chromosomes) 3 (formation of spindle fibers) 4 (alignment of chromosomes in the center of the cell) 5 (pinching of the cell membrane)