Question

why do fish and frog more lay more number of eggs where as cow and human begins usually give birth to only one at a time

Answer 1

Fishes n frogs lay thousands of egg at a time as their fertilization is external and many of their eggs get destroyed n damaged due to external fertilization and only some of them forms zygote ,this helps them to maintain their race whereas in mammals or human beings fertilization is internal and only one zygote is formed. In humans zygote is very safe inside mother's womb.

Answer 2

Answer:

Frogs and fish are oviparous and cows and human beings are viviparous.

Explanation:

Fish and frogs lay a greater numeral of eggs at a time because their fertilization is external whereas fertilization in cows and human beings is interior. Due to external fertilization in fish and frogs, the eggs exist at risk of obtaining destroyed by environmental elements and predators. The survival rate of the eggs is less in organisms that produce by external fertilization. Fish and frogs exist oviparous. This is why they lay thousands of eggs, to preserve their species.

Cow and human beings exist viviparous and they fertilize their egg by internal fertilization. It saves the fertilized egg from the external harsh atmosphere. The survival rate of young ones is increased in internal fertilization. Naturally. the embryo is covered inside the mother’s body. The fertilized egg is protected from environmental injury and predators. That’s why cows and human beings usually provide birth to only one at a time as one zygote is very secure in the mother’s womb.

#SPJ3