Question

Mollusks reproduce
A. Asexually
B. Sexually
C. Both A and B
D. None of the above

Answer 1

Hint:The second largest phylum of invertebrates is phylum Mollusca. Mollusks is a phylum which consists of soft-bodied invertebrate organisms. These organisms are partly or wholly enclosed in a calcium carbonate shell secreted by a soft mantle covering the body.

Complete answer: Molluscs are the largest marine phylum which comprises about 23 percent of all the named marine organisms. They are highly diverse with respect to structure, behavior, and habitat. The body of mollusc is soft and bilaterally symmetrical in shape. One of the examples of molluscs is the octopus. Understanding the reproduction of Molluscs is quite complex. The simplest species of molluscan reproductive system relies on external fertilization. All produce eggs which are female gamete released before fertilization. In external fertilization, the eggs are fertilized by the sperms released in the water. The gonads in mollusc are placed next to the coelom which forms a small cavity surrounding the heart. These gonads shed ova or sperm in the coelom. The gametes are extracted by the nephridia from the coelom and are emitted into the mantle cavity. Some species of mollusc are hermaphrodites that reproduce by internal fertilization. Therefore, option C both sexual and asexual reproduction is the correct answer.

So, option C is the correct option.

Note: Mollusks are of great importance as they are a source of food to humans. They also have medical importance to humans. Examples of Molluscs are squid, cuttlefish, snail, and slug. Even though molluscs are of great importance to humans, the bite of a blue-ringed octopus is fatal to humans.