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.
What there is to know about a Depth Micrometer. A depth micrometer is used to measure the depth of holes, slots, counterbores, recesses, and the distance from a surface to some recessed part. This type of micrometer is read exactly opposite to the method used to read an outside micrometer. The zero is located toward the closed end of the thimble. in depth amount as the thimble moves toward the base of the instrument.