The food for the developing embryo is stored inside the egg, often even before the embryo is there at all (before fertilization occurs). Females produce ova (eggs), and these are very large special cells that have stored vitellum (yolk). The vitellum is formed by proteins, fats and carbohydrates that will be degraded to produce energy, water and macromolecular components to form the body of the new developing individual. Once the embryo starts to grow and its tissues expand, the vitellum stays connected to it, usually near its developing gut.
Some species have very yolky eggs, i.e. with lots of vitellum, and with enough vitellum to go by, these embryos can undergo direct development and hatch as miniature adults. For instance, the eggs of birds or turtles.
Other species have moderate amounts of vitellum or almost none, and in those cases the development of the embryo within the egg is usually shorter. The new individual hatches as a larva that is able to feed, and in fact it needs to feed in order to grow and metamorphose into an adult. Example: the caterpillars of butterflies and moths, the alevin larvae of many bony fishes.
So they don't eat with their mouths, they have their storage bag directly attached to their guts!
2006-06-30 07:04:36
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answer #1
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answered by Calimecita 7
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Species have evolved so that there is food/nutrition within the egg to provide the nourisment for the animal/insect to grow.
2006-06-30 08:13:07
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answer #2
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answered by Anonymous
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just like a God-given fetus in a mother's uterus, the baby is not physically eating. Similarly the animals and insects are merely absorbing the nutrients which cause cell production until there is actually a baby animal or baby insect
2006-06-30 14:07:33
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answer #3
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answered by Ilovechristjesustheking 3
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Because the inside of the egg is full of proteins which help the unborn animal to grow and develop, and that is why eggs have so many calories.
good luck.
2006-06-30 08:12:44
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answer #4
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answered by john 6
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In most birds and reptiles, an egg (Latin ovum) is the zygote, resulting from fertilization of the ovum. It nourishes and protects the embryo.
2006-06-30 09:22:55
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answer #5
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answered by a13 4
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The eggs contain all the food they need until they hatch.
2006-06-30 10:13:22
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answer #6
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answered by survivor 5
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Well if you mean after it hatches it's just plain instinc as a younge animal.
2006-06-30 10:02:21
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answer #7
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answered by Summer C 2
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32 million years of evolution.
2006-06-30 08:10:45
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answer #8
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answered by ? 6
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they dont require food but warmth.They contain amino acids and proteins.
2006-06-30 08:12:38
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answer #9
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answered by shubh 2
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