Which structure fuses to form a diploid zygote during sex reproduction

Male and female gametes fuse together to form a diploid zygote during sexual reproduction.

Explanation: Sexual reproduction is a process in which male and female gametes fuse together to form new organism.

Male gametes are known as sperms and female gametes are known as eggs.Sperm and egg are haploiy. By the fusion of sperm and egg a diploid cell is produced , known as Zygote. Fusion of male and female gametes is known as fertilization. Zygote contains genetic information half from mother and half from father. From zygote embryo is developed.

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.