Phospholipids make up most of the lipid part of the cell membrane. since water exists on both the outside and inside of a cell, which of the following phospholipid arrangements makes the most sense? a single layer of phospholipids with the polar heads facing outside the celltwo back-to-back phospholipid layers with the non-polar tails facing out on both sidesa single layer of phospholipids with the polar heads facing inside the celltwo back-to-back phospholipid layers with the polar heads facing out on both sides

Two back-to-back phospholipid layers with the polar heads facing out on both sides

Explanation:

Phospholipids are made up of a head  and two tails. The head can be described as a phosphate molecule that is water loving (hydrophilic) whereas fatty acids make up the two tails. The fatty acids repel water and hence are hydrophobic. The assembling of the phospholipids for the the formation of cell membrane depends on these hydrophilic and hydrophobic properties. The assembling of the phospholipids is in two layers. The phosphate head face outwards on both sides to attract water and the tails tend to hide from the water molecules by being composed in the layers of the head. this assembling is termed as the "self-assembly".

prophase: we can observe the chromosomes to coil up and condense. they become visible. nuclear membrane and envelope disintigrate.s

metaphase: chromosomes align at the center, the metaphase plate. spindle fibers attach to centromeres of the sister chromatids. they meet at kinetochores.

anaphase: sister chromatids are pulled towards each opposing centromere, set on different poles.

telophase: chromosomes are now clustered up only on either sides of the cell. nuclear membranes reform, and a new cell wall forms along the cell plate. this will lead to cytokinesis, the process that divides the cell membrane and forms the cell wall.