The self regulatory process of the organism which tends to maintain stability and internal body temperature is known as homeostasis.
The higher animals such as mammals tend to maintain a constant internal environment despite of the changes occurring in the external environment.The maintenance of the body temperature is essential for the functioning behavior of body enzymes and proteins.
The feedback mechanism is the process where in the upregulation and downregulation of genes, hormones, homoeostasis and other factors are controlled.
This system of mechanism allows the body to retain its own internal state.
A cell is said to be homozygous for a particular gene when identical alleles of the gene are present on both homologous chromosomes.