The structure of the respiratory system and the circulatory system meet is the

Liquid water turns into water vapor at which step in the water cycle? a. precipitation o b. water run off c. evaporation d. condensation

Aresearcher has developed two stains for use with seed plants. one stains sporophyte tissue blue; the other stains gametophyte tissue red. if the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur? a) the pollen grains will be pure red.b) the pollen grains will be pure blue.c) the pollen grains will have red interiors and blue exteriors.d) the pollen grains will have blue interiors and red exteriors.

Acell in the human nervous system whose primary function is to form myelin and the blood-brain barrier, respond to injury, remove debris, and enhance learning and memory is called a(n) cell.