1. Three brothers have blood types A, B, and O. What are the chances that the parents of these three will produce a fourth child whose blood type is AB? Because the parents are the same, the genes involved stay the same; therefore, the probability will stay the same for each born child. A chance 25% will always be AB, as well as, 25% for A, B, & O. The number of children had prior does not alter the chances of blood type to be produced. back to questions

2. What determines the sex of the Philippine crocodile? The sex is determined by the temperature at which the eggs incubate. Females result from lower temperatures and males result from higher temperatures. back to questions

3. Who first classified fingerprints as a means of identification? It is generally acknowledged that Francis Galton (1822-1911) was the first to classify fingerprints. However, his basic ideas were further developed by sir Edward Henry (1850-1931), who devised a system based on the pattern of the thumbprint. In 1901 in England, Henry established the first fingerprint bureau with Scotland Yard, called the Fingerprint Branch. back to questions

4. What is the length of the strands of DNA in the nucleus of a single human cell? About three feet. back to questions