Why hen lays one egg whereas fish and frog 100 eggs?

It's not accurate to say that a hen lays only one egg, and that fish and frogs lay 100 eggs. Here's why:

* Hens lay multiple eggs: A hen can lay anywhere from 4 to 30 eggs in a clutch, depending on breed and factors like diet and age. They lay one egg per day, usually.

* Fish and frog egg counts vary: While some fish and frog species lay hundreds or even thousands of eggs, others lay only a few. The number of eggs depends on the species, their environment, and their reproductive strategies.

The reason for different egg numbers:

* Parental care: Birds like chickens provide a significant level of parental care, incubating their eggs and caring for the young. They can afford to lay fewer eggs because their offspring have a higher chance of survival.

* Survival rates: Fish and frogs often lay many eggs because their offspring face a much higher risk of predation and mortality in their early stages. The sheer number of eggs increases the odds that at least some offspring will survive to adulthood.

* Reproductive strategies: Different species have evolved various reproductive strategies, each with its own advantages and disadvantages. For example, some fish lay eggs that are dispersed in the water, while others lay eggs in nests.

In summary: The number of eggs laid by animals is a result of a combination of factors, including their reproductive strategy, the environment they live in, and the level of parental care they provide.