What is the name for a group of similar cells that preform a special function?

The process of meiosis produces only gametes, eggs or sperm. according to the diagram, how many sperm are formed from each cell that undergoes meiosis?

3. in the fruit fly, recessive mutation brown, b, causes brown color of the eye and absence of red pigment. recessive mutation p of another independent gene causes purple color of the eye and absence of brown pigment. the cross of a brown-eyed female and purple-eyed male produced wild type eyes. what will be the colors and their ratio in f2?

In figure 1-2 what is the distance from point b to point c?