The larva

The idea

Animals laying hundreds to thousands of eggs at a time give each egg only enough yolk to produce a larva, an intermediate feeding stage that eats and grows before transforming into the adult.

Eggs by the thousand

Fish, amphibians (such as frogs) and insects (such as butterflies) lay hundreds to thousands of eggs at a time.

Why do you think animals that lay thousands of eggs make eggs with so little yolk?

• The mother cannot give enough yolk to so many eggs
• The eggs do not need any food
• Yolk is harmful to the egg

Egg to adult

Press Next step to follow one egg.

Just enough yolk

A mother cannot give a lot of yolk to thousands of eggs. So each egg had just enough yolk for a larva. The larva fed itself and grew before it changed into an adult.

Animals laying hundreds to thousands of eggs at a time give each egg only enough yolk to produce a larva, an intermediate feeding stage that eats and grows before transforming into the adult.

Notes

Animals laying hundreds to thousands of eggs give each only enough yolk for a larva, a feeding stage that eats and grows and then becomes the adult.

Check yourself

Why does each egg of a fish, an amphibian or an insect have only a little yolk?

What is the larva?

In which of these does a larva change into an adult?

What does the larva eat to get nutrition?

• The mother's body cannot provide so much yolk for so many eggs — correct. Yes!
• The egg does not need yolk at all. The yolk contains nutritive substances to nourish the developing embryo.
• The larva gets all its food from its mother's body. The larva gets nutrition by eating organic wastes like rotten food, manures and so on, and grows.
• The fully grown adult. The larva changes into the adult after enough nutrition has been stored.
• An intermediate feeding stage that eats and grows — correct. Yes!
• The yolk inside the egg. The yolk is inside the egg. The larva hatches from the egg.
• A bird. Birds lay eggs with enough yolk to nourish the embryo until it hatches into a young one.
• A human. In mammals the zygote grows and develops inside the female body.
• A butterfly — correct. Yes!
• Organic wastes like rotten food and manure — correct. Yes!
• The yolk of other eggs. The larva gets nutrition by eating organic wastes like rotten food and manure.
• Milk from its mother. Milk is fed by mammals to their young ones.