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, or recombination, is the exchange of chromosome segments between nonsister chromatids in meiosis. Crossing over creates new combinations of genes in the gametes that are not found in either parent, contributing to genetic diversity.