When you exhale onto a cold window pane water vapor in your breath condenses on the glass. where does the water vapor come from

It comes from  inside your lungs. It's warm and wet inside your lungs and warm air holds more moisture than cold so when you breathe out you are expelling very humid air that is just looking for somewhere cold to condense.

gametes or germ cells are haploid cells (example: sperm and ova) containing only one set (or n) number of chromosomes and autosomal or somatic cells are diploid cells containing 2n number of chromosomes.

b brown mice / white sand dunes