Why is the presence of an integral protein necessary for a charged particle, such as an ion, to cross a cell membrane?

Alternation of generations in angiosperms the diagram below illustrates the alternation of generations that is characteristic of the angiosperm life cycle. label structures and processes (using white labels), indicate whether different structures are haploid or diploid (using pink labels), and indicate the types of cell division that occur at different points in the life cycle (using blue labels). drag the labels to their appropriate locations on the diagram of the angiosperm life cycle. labels can be used once or more than once. use only white labels for white targets, pink labels for pink targets, and blue labels for blue targets. a. meiosisb. haploidc. mitosisd. ametophytee. pollinationf. meiosisg. haploidh. mitosisi. ametophytej. fertilizationk. zygotel. diploidm. sporophyte