why do eggs have yolks?

Answer 1

Yolks provide the nutrition needed by the embryo. Since eggs are a kind of self-contained embryonic environment; it's the only way to nourish the growth.
It's like the embryo had to pack its every meal up until hatch-time. Thats the yolk.

Answer 2

The yolk in a newly laid egg is round and firm. As the yolk ages it absorbs water from the albumen which increases its size and causes it to stretch and weaken the vitelline membrane (the clear casing enclosing the yolk). The resulting effect is a flattened and enlarged yolk shape.

Yolk color is dependent on the diet of the hen; if the diet contains yellow/orange plant pigments known as xanthophylls, then they are deposited in the yolk, coloring it. A colorless diet can produce an almost colorless yolk. Farmers may enhance yolk color with artificial pigments, but in most locations, this activity is forbidden.

[edit] Abnormalities
Three eggs frying, two of which are double-yolked eggs.
Three eggs frying, two of which are double-yolked eggs.

Some hens will lay double-yolked eggs as the result of unsynchronized production cycles. Although heredity causes some hens to have a higher propensity to lay double-yolked eggs, these occur more frequently as occasional abnormalities in young hens beginning to lay.[citation needed] Usually a double-yolked egg will be longer and thinner than an ordinary single-yolk egg. Double-yolked eggs occur rarely, and will only lead to the successful development of two embryos with human intervention.[5]

It is also possible for a young hen to produce an egg with no yolk at all. Yolkless eggs are usually formed about a bit of tissue that is sloughed off the ovary or oviduct. This tissue stimulates the secreting glands of the oviduct and a yolkless egg results.

Answer 3

According in my studies,

eggs have yolk because yolk is the chick, without yolk no chick, with out chick no chicken with out chicken no egg.

Answer 4

Eggs have a yolk solely for the purpose of having eggs, sunnyside up.

Answer 5

Eggs have "yolks" because they have a wonderful sense of humor and love to make people laugh. Get my "yoke?" Hahahahaha

Answer 6

its very simple bro.its bcs its an egg. eggs have yolk. dont say u didnt attend any biology classes

Answer 7

becuase thtas the unfertilized babay inside. but it just wont hatch because its not fertile. so there is really no way besides that to know why they have yolks inless you do research.

Answer 8

To feed the growing chick, if fertilised.

Answer 9

they are basically the "womb" which would develop into a chick if it was fertilized by a rooster.

Answer 10

the same reason wombs have babies!!!!!!
do you know what a womb is?