NEET BIOLOGY

Detailed explanation-1: -Because it happens outside of the body, we call this “external fertilization”. External fertilization in animals usually occurs in water or in damp areas in a process called spawning. Moisture in the environment keeps the gametes from drying out.

Detailed explanation-2: -External fertilisation can occur both in water and on land.

Detailed explanation-3: -Among vertebrates, external fertilization is most common in amphibians and fish. Invertebrates utilizing external fertilization are mostly benthic, sessile, or both, including animals such as coral, sea anemones, and tube-dwelling polychaetes. Benthic marine plants also use external fertilization to reproduce.

Detailed explanation-4: -In aquatic animals, fertilization takes place in water. They release their gamete (sperm and egg ) in water which fuses to form a zygote. As fertilization takes place outside the body so it is known as external fertilization and such animals are known as oviparous as the embryo development takes place in the egg.

Detailed explanation-5: -External fertilization in an aquatic environment protects the eggs from drying out. Broadcast spawning can result in a greater mixture of the genes within a group, leading to higher genetic diversity and a greater chance of species survival in a hostile environment.