Expert: Walter Hintz - 8/15/2010

Question
I am a year 11 student currently doing my latest biology assessment which involves having to list the similarities between external and internal fertilization. I personally was unable to see any other similarities either then both needing a male and female and both able to produce offspring. If you are not comfortable in answering what may be school work, then are you able to give me some websites that are realizable in helping me find the answers? I wish to use a range of sources like journals and articles but it is hard to find reliable ones on the internet. Thank you :D

Answer
Hi Carol
 There  are more differences then similarities but the most obvious similarity is that in both cases fertilization requires a liquid medium. Aquatic species can release gametes directly into the water while sea mammals and all terrestrial organism must use an intromittent organ (penis)to place sperms into the female. Amphibians use external fertilization but must return to the water to fertilize eggs. Birds have variation with some have a penis while others merely join cloaca. If you want to pursue articles and literature I would suggest you look through zoology texts for the chapters on reproduction. Also check some information of invertebrates. Crustaceans like lobsters and crayfish use internal fertilization.Since you are Australian you may want to discuss the platypus and the echidna
If I can help you more use my e-mail address (waltjh@sbcglobal.net)