Question

What mechanisms have evolved in animals with (a) external fertilization and (b) internal fertilization that help ensure that offspring survive to adulthood?

Answer 1

external fertilization:

✓ this occurs mostly in aquatic organisms.

✓ the aquatic organisms produce more number of sperms and eggs. So they have more chance of fertilizing with each other when compared to less number of cells.

✓ the aquatic environment protect the eggs from drying out.

✓in external fertilization the femlae lays their eggs in water and then male lays their sperms into the same water at the Same time so their is a a greater chance of genetic diversity.

Internal fertilization: occurs in organisms on land

✓ the internal fertilization protect the embryo from dehydration as this occurs on organisms on land so they need this protection from dehydration.

✓ this protects the young one from predators.as their are more predators for those young ones.

✓ survival rate is high as they are protected by their mother and their nutrition is also provided by their mother itself so they have every thing to grow hence their are many more survival chances than ever.