When two dihybrid individuals are mated, this is called a dihybrid cross. Even though the parents of a dihybrid cross have the same genotype and phenotype, their offspring could show any one of 9 different genotypes and 4 different phenotypes. The phenotypic ratio of offspring produced from a dihybrid cross is 9:3:3:1. To unlock this lesson you must be a Study.com Member.
Sounds are heard by the ear as either being loud or soft. The loudness of a sound in measured in decibels. Decibels refer to the energy produced by that sound. A human can hear sounds ranging from 0.1 decibels, which is very soft, to sound which measure 120 decibels. Younger people can often hear lower volumes better than older people.
While 20 to 20,000Hz forms the absolute borders of the human hearing range, our hearing is most sensitive in the 2000 - 5000 Hz frequency range.As far as loudness is concerned, humans can typically hear starting at 0 dB.itch is measured in Hertz (Hz) and loudness is measured in decibels (dB). For a person with normal hearing, when it comes to pitch the human hearing range starts low at about 20 Hz. Thatâs about the same as the lowest pedal on a pipe organ.