in species where young are brought to term in a womb they are given everything they require to grow and develop, via the placenta so how do young grow and develop in an egg when there is no connection to the mother how do they get every thing they need??
2007-12-10 09:58:44 · 5 answers · asked by I hate little green pigs 3 in Science & Mathematics ➔ Biology
There is a yolk sac inside the egg that keeps the fetus alive. It contains all the nutrients the growing fetus will need. The yolk sac starts out 20 times the size of the fetus and when the baby is ready to hatch, the yolk sac has disappeared.
Even human embryos have a yolk sac for the first trimester. This develops as the embryo is traveling to an implantation site. The yolk provides all the nutrients until the placenta can take over. Then it disappears too.
2007-12-10 10:06:53 · answer #1 · answered by Malina 7 · 0⤊ 0⤋
Everything they need is in the egg, or diffuses through the shell.
So, the yolk and white of a chicken egg provide all of the needed minerals, amino acids, lipids and water. Oxygen can diffuse into the embryo through the shell.
2007-12-10 18:08:19 · answer #2 · answered by hcbiochem 7 · 1⤊ 0⤋
Everything is in that egg. Warmth sometimes comes from the mother, like a goose sitting on her eggs.
2007-12-10 18:10:41 · answer #3 · answered by MLBfreek35 5 · 0⤊ 0⤋
they have storage of nutrients in the egg. thats where they are getting enough nutrients to grow and develop
2007-12-10 18:15:39 · answer #4 · answered by zynpylmz 1 · 0⤊ 0⤋
That's probably one of the best questions I've read all day.
2007-12-10 18:06:13 · answer #5 · answered by ladylove 3 · 0⤊ 0⤋