Yini eyenza isilwane sibe yi-monotreme?
I-monotreme isilwane esincelisayo esizalela amaqanda. Lokhu akuvamile njengoba kunezilwane ezincelisayo ezimbili kuphela, i-echidna ne-platypus, ezikwenzayo lokhu. Iningi lezilwane ezincelisayo lizala i-placenta, kanti ezinye ezincelisayo ezincane, ezaziwa ngokuthi ama-marsupial, zizala umbungu ofana nesibeletho ozincike esibelethweni sikamama ukuze uzondle kuze kube yilapho usukhule ngokuphelele.