They usually have broad round faces, saddle-shaped nose profiles, and thick tongues that are often stuck out of their mouths. The incidence of Down syndrome children goes up rapidly with the age of the mother, particularly after 40. Ribosomes are on the surface of these bodies. Both men and women produce them, but females normally produce much more. Complex single celled creatures such as protozoa as well as all multicelled plants and animals are eukaryotes.
People have eukaryotic cells.
See prokaryotic cell . See introns . Gametes are produced by meiosis . They normally have half the number of chromosomes found in somatic cells. A gene may be made up of hundreds of thousands of DNA bases.