For hh, the gametes can only carry h (the recessive allele). For both heterozygous individuals (Hh), the gametes can carry the H (dominant allele) or the h (recessive allele). For Hh, the gametes can carry the H (dominant allele) or the h (recessive allele). For HH, the gametes can only carry H (the dominant allele).
Aristotle's model shows the planets in the celestial realm moving around the Earth in an orderly manner, in perfect circles and with uniform motion-neither speeding up nor slowing down.