Answer:
If the man has blood type A one of whose parents had blood type O then he must be having the genotype IAi and the woman with blood group AB would have genotype IAIB. So if they produce offspring than the putative genotype of the offspring would be IAIA, IAi, IAIB, and IBi.
IA i
IA IAIA IAi
IB IAIB IBi
Therefore out of four offspring, two offspring would be having A blood group, one offspring would have AB blood group and one offspring would have B blood group.
Chemical signal can signify the lymphatic, nervous and endocrine system.
Mostly endocrine, the endocrine system is the body system responsible for providing the needed hormones for the body. These hormones and body fluids contribute and catalyse the growth, disposition, sex characteristics and other potential corresponding output of these hormones.