Phospholipids are complex molecules with a lipid "tail" and a phosphate "head." which end interacts with water? neither phosphate head lipid tail

According to the big bang theory, after the "bang," the universe remained dark until about  300,000 yearsone billion yearsthree minutesthree billion years  later, when neutral atoms began to form.

Me with biology endocrine system crossword also image left i need with hw

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?