Asexual reproduction in sharks usually occurs through a process called “automatic parthenogenesis”. explained Feldheim. During egg development, an egg is produced along with three other products called polar bodies. Usually these polar bodies are simply reabsorbed by the female. Can ...

Although birds have lungs, their structure is relatively rigid, as they do not spread and contract as in many mammals, reptiles, and amphibians. Instead, the structures that act as the bellows that ventilate the lungs are air sacs, which are ...