From the knowledge on genetics; GgTt pea plants can produce four types of gametes, but a ggtt can produce one type of gamete. A GgTt is heterozygous therefore they carry different versions of a gene, while ggtt is homozygous thus carrying the same version of a gene. Therefore, GgTt can produce GT, gT, Gt, gt, (four gametes) while ggtt can only make a gt ( 0ne gamete).
