In humans, brown hair is dominant over blonde hair. Also in humans, detached earlobes are dominant over attached earlobes. If a male that is heterozygous for both traits has children with a female that is heterozygous for both traits, their offspring’s phenotypes would be represented by which of the following ratios: *

A)4:4:4:4

B)9:3:3:1

C)16:0

D)3:1

B) 9:3:3:1

Explanation:

A punnet square can be described as a diagram in which the outcomes of a cross between parent carrying certain traits can be studied.

A cross in which only one trait is studied will be termed as a monohybrid cross. For example, making a cross for just hair colour.

A cross in which two traits are being studied at a time is termed as a dihybrid cross. For example, studying the hair color and the pattern of earlobes in a single punnet square.

The pnnet square for the scenario discussed in the question can be made as follws:

              BE               Be                bE                 be

BE     BBEE         BBEe             BbEE             BbEe

Be     BBEe         BBee             BbEe             Bbee

bE     BbEE         BbEe              bbEE             bbEe

be     BbEe        Bbee               bbEe               bbee

The results of the cross show that :

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.