Eye color: The myth. One of the oldest myths in human genetics is that having blue eyes is determined by a single gene, with the allele for blue eyes recessive to the allele for non-blue eyes (green, brown, or hazel).Many people who know nothing else about genetics think that two blue-eyed parents cannot have a brown-eyed child.ye color: The myth. One of the oldest myths in human genetics is that having blue eyes is determined by a single gene, with the allele for blue eyes recessive to the allele for non-blue eyes (green, brown, or hazel).
Micrometer Caliper. a measuring instrument whose conversion mechanism consists of a screw-nut micropair. Micrometer calipers are used to measure linear dimensions by the absolute contact method.omplete turns are read from a scale marked on the hub of the micrometer caliper, and fractions of a turn are read from a circular scale marked on the drum. A displacement of the screw of not more than 25 mm is optimum because of the difficulty of manufacturing a screw with an accurate pitch over a greater length.
At this scale, we have our micrometer divided into. thousandths. One 1000th of a micrometer is a nanometer, or nm. Notice that the. nanometer is three orders of magnitude smaller than the micrometer, which is. three orders of magnitude smaller than the millimeter, which is three orders of. magnitude smaller than the meter. Therefore, one nanometer is 1/1,000,000,000. of a meter. Identify and label the nm.