Internal - they're mammals.
Platypus fertilisation occurs internally.
Several diagrams of the platypus - both external and internal - can be found at the related link below.
internal. the male needs to 'mate'with the female
how does the mourning show internal and external responses to its environment
Internal, since it lays eggs, the platypus would have to be fertilised internally. Raphael Yee Singapore
They are receptors.
internal external not internal external not
Responses or reactions we make or activities we engage in.- Association between stimulus (S) and response (R). - [(S) and (R) can be internal/ external]
Is a salmon internal or external?