Because there are two kinds of plant germination: unearthed germination and retained soil germination, the unearthed hypocotyl elongates and pushes the cotyledons out of the soil. Usually, this cotyledon will produce chloroplasts under light, which will make nutrients for the initial development of buds.

When we usually eat bean sprouts, you can observe that the cotyledon is on it, so we eat the hypocotyl below the cotyledon.

Melons and most beans germinate in the soil, while corn, wheat, broad beans and peanuts germinate in the soil. )

I hope my answer is helpful to you.