Upsampling adds more pixels/dots per inch (dpi), but creates blurry images, ugly blocks of color, and high contrast in images. The only way resolution can be improved is by decreasing the image size, or by recapturing the image at a higher quality setting.
Postcrossing is an online project that allows its members to send and receive postcards from all over the world.
Crossing over is the mutual exchange of pieces of chromosome, so that groups of genes are swapped between paternal and maternal chromosomes. This takes place during late prophase of meiosis 1.