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Anonymous
Anonymous asked in Science & MathematicsBiology · 1 decade ago

Can anyone help me to understand eggs?

I would love to really understand how they work. Chickens lay them unfertilized - do other animals? Does the egg get fertilized after it has formed a yolk? How does the baby chick connect to it? Do the answers apply to reptiles, fish, lobsters? Any info gratefully recieved.

Update:

I promise this is not homework. I'm just really nterested!

Update 2:

interested I mean.

4 Answers

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  • 1 decade ago
    Favorite Answer

    This is not homework hour....get your lazy bombom out of the pc and read your book.

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  • Anonymous
    1 decade ago

    First on types of fertilization: The common unfertilized chicken egg is a product of hundreds of years of selectively breeding chickens that lay lots of eggs. Most birds, reptiles, and insects (land creatures) only lay fertilized eggs though I'm sure there are some exceptions - these eggs are fertilized with male-female copulation. Most fish, amphibians, and other water dwelling creatures lay unfertilized eggs in the presence of a male who ejects a fog of sperm in the water around the pile of eggs where they are fertilized. Female salmon are famous for faking orgasms to get lots of males ejecting lots of sperm before laying eggs. After fertilizing the eggs, a male seahorse quickly swollows the eggs to protect them - some call this a case of male pregnancy.

    Yolk and baby chick connecting to it: The egg is actually a single cell and the yolk is initially part of the egg. Newly "hatched" fish look like a head and tail with a yolk in between. If you can find someone that has roosters in with hens, you can get eggs that are fertilized (no commercial eggs are sold fertilized, so you should try a specialty grocer or farmer's market) you will find a very small red spot on the yolk. This is basically the spot where the male and female DNA joined and are now forming what becomes the visible chick. After fertilization, biologists don't call it an egg any more because it begins to change and the one cell begins to make new cells of various shapes and sizes - before this happens the egg is a single cell and there really isn't a chick. At that point, the yolk is usually pushed outside of the new body plan so that it doesn't get in the way (though many fish place it where the gut will be) and a placenta-like connection of blood vessels grow around it to harvest the yolk's energy - you can see this pretty well in a chicken egg a few days after fertilization, provided the egg is well incubated.

    For a really cool experiment, put a few eggs into a jar and cover them with vinegar. Vinegar is an acid and calcium is soluble in acid. Cover loosely - but do not cap because gas is given off and the jar could explode - and set somewhere you can't smell it. It only takes about 30 minutes to soften the egg shell and you can carefully peel the shell off of the egg and see inside. After about an hour the shell is about 1/2 gone but the acid has all bonded with the calcium and is "used up". Drain the eggs (I pick them up carefully and place on a plate) and repeat. After another hour soak, there should be very little shell left and you can pick up the egg (carefully) and clearly see what it looks like before you crack them to fry. For decades scientists have actually succeeded in doing this without killing the chick and are able to watch chicks develop without any special tools.

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  • 1 decade ago

    From my own experience a hen (female chicken) that has not been with a rooster (male chicken) the eggs will not be fertile.Eggs in a hen form in a chain so to speak.They run from the actual egg as we know it to as small as the end of your little finger.When a rooster breeds a hen she has the ability to hold the sperm in side her to fertilize the eggs as they are worked up the chain.Some hens lay daily while some lay every other day.The egg as it is layed is replaced by a new egg on the chain.Keep in mind the eggs on the chain form as they work up the line,sperm is introduced before the shell begins to form on the egg.Some hens when they are first starting to lay will lay eggs that are soft shelled,this can also be true if the hen is old,malnourished,or put into a shock due to a accident or being moved to a new place.It takes 21 days for a chick to hatch.The cycle of life for their growth is not much different than ours.You can actually take a new born chick and mash it and yolk will come out of it's rectum.

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  • Anonymous
    1 decade ago

    Well. you asked so many questions... I would not know where to start.. So.. I will start with.. Chickens lay unfertilized eggs.. No, not necessarily. Sometmes they are fertilized and sometimes not.. Does the egg get fertilized after it has formed a yolk? The egg may get fertilized during the formation of the egg.... If the egg is fertilized, then under warm conditions, etc, the baby chick will form within the egg using the yolk as its food source which will bring it to the hatching stage... and yes.. all other egg bearing creatures have the same process.

    I would like for you to go to this URL.. click on it and you will learn more..

    http://www.enchantedlearning.com/subjects/birds/in...

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