what is the life cycle of a seashell?

Question

with illistration

Answer 1

A seashells life cycle is the same as the creature which lives in it. It isn't alive, it is like a "house" which the creature lives in. The shell is generally composed of calcium carbonate, which is secreted by the outer surface of the mantle (a skinlike tissue in the mollusk's body wall) of the shell as the creature ages. The composition can be thickened, enlarged and repaired, but does not play a part in the metabolism of the animal.The shell serves as an exo-skeleton to protect the soft body against the outside world.
The color and design of the shell is mainly dependent on the diet of the animal. In warmer waters where a variety of food sources are abundant, you will find thousand of species in all shapes, sizes and especially colors. In colder waters where food sources are typically the same, you will find mostly darker shells lacking in any type of vibrant color.

A shell is the most universally identifiable part of a creature known as a mollusk. Mollusks are invertebrate animals (think of a snail) with an unsegmented, basically symmetrical body, generally consisting of head, foot, visceral hump and mantle. Mollusks are descendants from primitive wormlike creatures that inched around in the ooze of primeval seas millions of years ago. As dissolving land masses began to feed salts and chemicals into oceans, the first mollusks digested them and eventually used them to build durable shelters.
When the mollusk dies, its shell is the one part that typically remains intact; this is what you see washed up on beaches when you go to the ocean.

Below is a website with pictures of seashells:

Answer 2

Do you mean mollusks? If so, here is an illustration and explanations