In chickens, comb shape is determined by alleles at two loci (R, r and P, p). A walnut comb is produced when at least one domina
nt allele R is present at one locus and at least one dominant allele P is present at a second locus (genotype R_ P_). A rose comb is produced when at least one dominant allele is present at the first locus and two recessive alleles are present at the second locus (genotype R_ pp). A pea comb is produced when two recessive alleles are present at the first locus and at least one dominant allele is present at the second (genotype rr P_). If two recessive alleles are present at the first and at the second locus (rr pp), a single comb is produced. Progeny with what types of combs and in what proportions will result from the following crosses? a. RR PP × rr pp
b. Rr Pp × rr pp
c. Rr Pp × Rr Pp
d. Rr pp × Rr pp
e. Rr pp × rr Pp
f. Rr pp × rr pp
Explanation: Osmosis is a process in which water move from an area of low solute concentration to an area of high solute concentration through a selectively permeable membrane. For osmosis to occur, it must be through a selectively permeable membrane. Diffusion is the movement of molecules from an area of high concentration to an area of low concentration.
