$A$ characteristic showing continuous variation is controlled by a

Human skin color is determined by polygenic inheritance. How many types of phenotypes will be produced by the cross $AaBbCc \times AaBbCc$?

The inheritance of skin color in humans is an example of which of the following?

The grain color in wheat is controlled by three pairs of polygenes. When a red-grained wheat variety is crossed with a white-grained variety,an $F_1$ hybrid is produced. When the $F_1$ hybrid is self-pollinated,what fraction of the $F_2$ generation will resemble the parental phenotypes?

The phenotypic ratio obtained in quantitative inheritance of a dihybrid cross is

In a plant,the weight of fruits is determined by the number of dominant alleles for several genes. If seven categories of weight are obtained,how many loci are involved in this trait?