All of the following animals exhibit internal fertilization except
Answers
Explanation:
phylum mollusca , Annelida and Echinodermata exhibit external fertilization.
Answer:
Phylum Echinodermata, Phylum Hemichordata, Phylum Mollusca, Phylum Annelida
Explanation:
Most of the invertebrate water animals, which are water-dwelling, sessile, and benthic, rely on the external mode of fertilization.
External Fertilization is a method of reproduction commonly seen in aquatic animals. In this mode of reproduction, the male and the female gametes are released in abundance by the male and the female organism into the water body. The male gamete that is sperm is the motile gamete. The female gamete that is an egg is non-motile. The fertilization takes place outside the female body, unlike Internal Fertilization. The sperm fertilizes the egg cell in the water.
In External Fertilization:
- Millions of gametes are to be released to increase the chance of survival of a species owing to the harsh environments and predation in the aquatic environment.
- The release of the eggs in the water protects the desiccation of the eggs.it increases the probability of variations in the offspring due to the mixing of genes.
External fertilization is observed in certain animal phyla: Phylum Echinodermata, Phylum Hemichordata, Phylum Mollusca, Phylum Annelida most of them are aquatic, sessile like starfish or benthic animals.