Why must animals that have external fertilization produce large numbers of eggs, while animals that have internal fertilization can survive with producing relatively few?
2007-04-10 08:56:53 · 3 answers · asked by greg 1 in Science & Mathematics ➔ Biology
External fertilization requires a chance encounter between eggs and sperm. So, in order to maximize chances of reproduction, huge numbers of eggs and sperm are released. Also, the odds of a fertilized egg not being eaten by something and surviving to adulthood is really quite low. So, large numbers of eggs help insure that a few will survive.
2007-04-10 09:04:56 · answer #1 · answered by hcbiochem 7 · 2⤊ 0⤋
When animals eggs are external they are more suseptable to dangers of the environment and less will survive so many need to be produced. When it's internal they are more protected and less have to be produced.
2007-04-10 16:05:55 · answer #2 · answered by Mal 5 · 1⤊ 0⤋
Odds are better for internal fertilization thus less eggs are sufficient. External fertilization. exposes eggs to water currents,predators, and other environmental factors which decrease potential for fert.
2007-04-10 16:05:57 · answer #3 · answered by ttumdg86 2 · 2⤊ 0⤋