Examples of external fertilization can be seen in frogs, some marine invertebrates and many types of fish. External fertilization happens when sperm fertilize eggs outside of the body of the female animal. Often, in orde... More »

Animals that live in water, such as amphibians and fish, use external fertilization. The term refers to the process by which the egg is fertilized by the sperm in an open environment and not within the bodies of the orga... More »

The difference between internal and external fertilization is that internal fertilization occurs inside the body, whereas external fertilization happens outside the body. Fertilization is the process by which a sperm cel... More »

The difference between internal and external fertilization is that internal fertilization occurs inside the body, whereas external fertilization happens outside the body. Fertilization is the process by which a sperm cel... More »

After fertilization, the cells in the zygote divide rapidly to form a morula, which becomes the embryo after approximately five days. The fetus is present about eight weeks after the fertilization takes place. More »

Animals that live in water, such as amphibians and fish, use external fertilization. The term refers to the process by which the egg is fertilized by the sperm in an open environment and not within the bodies of the orga... More »

Open circulatory systems are found in mollusks, arthropods and several other invertebrates. Open circulatory systems work by pumping blood into a hemocoel, which in turn diffuses blood and pumps it back into the circulat... More »