In cattle, RR = red, Rr = roan, and rr = white. What are the predicted color phenotypes for the offspring from crosses between: (a) a red bull and a white cow (b) a red bull and a roan cow (c) a roan bull and a roan cow?  

a) 100% roan

b) 50% red, 50% roan

c) 50% roan, 25% red, 25% white

Explanation:

a) A red bull has the phenotype RR, a white cow has the phenotype rr. Let's do a punnett square. In its gametes, the bull only has R alleles to pass on, and the cow only has r alleles to pass on:

                               Bull

                        R               R

                r      Rr             Rr

Cow    

               r       Rr             Rr

The offspring can only be Rr, so all of them will be roan. (100% roan).

b) A red bull has the phenotype RR, a roan cow has the phenotype Rr. Let's do a punnett square. In its gametes, the bull only has R alleles to pass on, and the cow has an R allele and an r allele to pass on:

                               Bull

                        R               R

               R      RR            RR

Cow    

               r       Rr             Rr

50% of the offspring will be RR, and 50% will be Rr. So half of the offspring will be red, and half will be roan.

c) A roan bull has the phenotype Rr, a roan cow has the phenotype Rr. Let's do a punnett square. In its gametes, the bull has an R allele and an r allele to pass on, and the cow also has an R allele and an r allele to pass on:

                               Bull

                        R               r

               R      RR            Rr

Cow    

               r       Rr             rr

25% of the offspring will be RR, 50% will be Rr, and 25% will be rr. So half of the offspring will be roan, a quarter will be red, (RR), and a quarter will be white (rr)

answer: 20 percent

the fish culture has become a developing commercial practice in developing countries which is already prominent in developed countries of the world. the major fish protein demand is being supplemented in developing countries is   fishing to meet the needs of the growing population. therefore, in some developing nations, the percentage of animal protein from fish in the diet can be as high as 20 percent.