When do cells differentiate? That is, when do cells first become different kinds of cell-muscle cells, nerve cells, reproductive cells,
etc?

Which of these resources is used worldwide to make construction products, pottery, and porcelain

How does a gymnosperm prevent itself from pollinating the same tree

The current thought on the structure of the cell membrane is: a. a static phosphate sandwich of lipids b. a fluid-mosaic of phospholipids and proteins c. a bilayer of proteins with static lipid molecules d. an impermeable bilayer of protein molecules e. a static and permeable phospholipid single layer