How do embryos in eggs get oxygen?
145144
The shell covering an egg is porous !!.It allows Oxygen to enter into the egg and CO2 to move out of the egg!
182422
well it gives nourishment to the fetus.  it brings blood of the mother and fetus close together so there can be gas exchange and the fetus, basically giving it oxygen.  Also it bringsfood and water to the fetus along with taking away any metobolic waste that has been produced by the fetus
1063260
In most birds and reptiles, an egg (Latin ovum) is the zygote, resulting from fertilization of the ovum. It nourishes and protects the embryo. Oviparous animals are animals that lay eggs, with little or no other development within the mother. This is the reproductive way of many fish, amphibians and reptiles, all birds, the monotremes, and most insects and arachnids.\n\nSince there are well over 800,000 species of insects I'd say oviparity is the way the largest number of animal species reproduce.
483159
The egg is fertilized in the Fallopian tube.
371411
No. \n    Now let us look at the question deeply.\n \n 1)THE SHELL -- When an egg is laid, it has an outer shell of calcium carbonate. This shell will NOT increase or decrease in its weight any time after it is formed till the chick is hatched and even after that.The shell only protects the egg and allows gaseous exchange and plays no other role.\n \n2)THE YOLK & THE ALBUMEN -- This part of the egg contains two important things viz. the fertilized nucleus and the reserve food for the growth of the embryo/chick.\nThe fertilized nucleus is embedded in the yellow yolk and can hardly be seen with the naked eye initially ;but as the embryo begins to grow ,this embryo can be seen with the naked eye with its beating heart and the web of blood vessels (but you have to break open the egg and then it is a waste.)\n \n The raw material for the growth is drawn from the yolk(the yellow of the egg ) and the albumen ( the white of the egg. ), i.e. the reserve food is converted in to embryo and then the chick. There is no loss or gain of weight here.\n\nNow comes the crux of the problem.\n \n3)THE ENERGY OR THE FUEL FOR THE DEVELOPMENT -- The energy required for this development also comes from the SAME reserve food material (Yolk & Albumen).\n This conversion of food in to energy means LOSS in the weight. \n\n Thus, if you weigh a newly laid egg and newly hatched chick with the tattered shell the egg will weigh more. (you can discount the weight of the shell from both the readings).\n \n4)THE CONCLUSION -- The chick does not gain any weight in fact it has less weight than the egg. It begins to gain weight only when it begins to feed on its own.\nThis is applicable for all the birds.
108459
An egg, and a sperm both contain a nucleus which holds half of our DNA (23 chromosomes). All of our other cells contain 46 Chromosomes. In the lab, they harvest an egg from which ever species they are cloning, and they remove the nucleus. They can then take the nucleus of a normal 46 chromosome cell and put it inside the egg- where it's nucleus used to be. The egg then "thinks" it is fertilized and will start to divide, and grow. This embryo is an exact replica of the parent cell. Cloning is a form of asexual reproduction, because sex was not involved in the creation of the new embryo. There are many ethical issues surrounding cloning. Some argue that scientists are "playing God" because they are creating new life. Some say that if a human were to be cloned- it would have no soul because it was not created by God. There are too many ethical issues to type here, but you get the idea. You'll have to decide for yourself where you stand. Hope this helps. good luck in school
1033249
the egg stays where it is - in the ovary. it turns into seed there. so the pollen must germinate (into a structure called pollen tube) and this tube grows through the pistil and delivers the germ cells to fertilize the egg. cut open a ripening seed pod of a flower and u will see the growing seeds. or imagine a green pepper cut open or green peas in the pod -  the seeds are attached to something that is called placenta, actually. and before fertilization they were not seeds but eggs. and through this place of attachment they were fertilized. it is not like human egg that itself travels from ovary to uterus and gets fertilized on the way.
611771
to allow the eggs to be released from the ovaries and travel into the fallopiian tubes.
1182923
Just one. \n\nVery few animals produce more than one offspring per egg.
501228
when air is compressed, it heats up. this could be circulated within the incubator to warm the eggs.
915464
In the alveoli the exchange is simply the difference in concentraions, diffusion.  The high concentration of oxygen in the lungs and low concentration of oxygen from the pulmonary artery (the opposite for CO2) follow the laws of diffusion.  In muscle cells CO2 is released by the muscle in combination with water to form H2CO3, an acid, as well as lactic acid.  The acidic environment results in what is called a Bohr shift, which decreases the affinity of oxygen to the hemoglobin to which it is attached.  This way the cells in the body can get oxygen on demand: cells with a higher metabolism get priority over cells with lower metabolism.\n\nSide note:\nCarbon monoxide prevents hemoglobin from releasing its oxygen creating an anoxic state.
283472
It forms the embryo.  The rest of the blastocyst forms the placenta, and the connective tissue to the mother
867974
Oxygen transfers via osmosis through cell walls  from regions of high concentration (ie, the haemoglobin) to the tissue cells where there is a lower concentration. At the same time the tissue cells release carbon dioxide which lowers the partial pressure creating a diffusion gradient for the the oxygen to move along.
43620
To make a baby you need a sperm cell and an egg cell. The sperm cell comes from the daddy and the sperm cell comes from the mommy. When the sperm and egg meet, they make a tiny baby that is smaller than a grain of salt. The baby grows in the mommy's tummy for nine months. Then the baby is ready to come out.
352313
ok how basic you want it to be\n\nthe first part is definitely the fertilization (you know what it is but here is some detail) sperms are tiny cells they contain condensed DNA and as organelles they only have mitochondria and acrosome. acrosome is a tiny vesicle surrounded by actin filaments and its job is to degrade the zone pellucida in non mammals and the vitelline envelope in mammals. as the sperm contacts with the egg (there is a potential chemical attraction but nobody's sure what does this attraction)the sperm relases those digestive enzymes and works its way down to the cell membrane where it contacts some its receptors which are thought to be species specific and inserts its DNA. along with this insettion a whole lot of calcium ion fluctuations occur in the cell mainly with the work of PKA and the sacroplasmic reticulum. Both nuclei meet in the middle of the cell and fuse and we get to the second part. \n\nthe second part is definitely the most important time of your life called the blastula. I will use 3 organisms sea urchin, from (xenopus to be more precise) and mice. \n\nin sea urchin the process is simple after fertilization a whole fury of cell division starts. by the time there are 129 cells or so instead of having a mass of cell we have hollow ball of cells with whole lot of signaling molecules secreted inside. then this ball form a cavity with the movement called invagination (hence the name tells everything) and closes that gap. now we have 2 balls infued with one another and that is the blastula stage. \n\nin mice the process is quite similar to sea urchins with couple of differences such as the speed of division is way slower and mammals show rotational division (search for this i cannot expain with words you need images)\n\nin xenopus the stage of blastula is quite different in the sense that the egg yolk in bird and frogs and some fish are really dense so the division cannot be completed right away. imagine a sphere and the top part of this sphere is not as dense as the bottom part as divisions start after fertlization it goes pretty well at the top but slows significantly at the bottom. The top part is called the animal pole and the bottom part is called the vegetal pole. usually 8 divisions start one after another without waiting them to finish dividing so you have unequal # of cells alot more at the top and way little at the bottom. blastule formation occur very similarly as in sea urchin but instead of having 2 hollow balls you get one cavity in a shpere\n\n\nnext process is called gastrulation and i will explain it later then we can move into cell specification and differentiation of ectoderm mesoderm and endoderm after that i will talk about limb development and some basic principles of gene activation \n\nthe rest of development is when hell breaks loose and is different for all taxa
914782
I actually turned this exact lab in at the begining of this semester for my College Bio class for Osmosis.  The shell of the egg does dissolve in the vinager and the egg still has the membrane attached.  After being in the vinegar you put it in the syrup and the syrup draws the water out of the egg because the syrup is heavier and has larger molecules that will not go into the egg and the egg is all shriveled up and the volume of the syrup is increased by 50 ml after being in the H2O for 24 hours it will draw the water back into the egg and your volume will decrease by 50ml.  It feels like a water balloon it is awesome.  If you get a chance, go ahead and do the experiement, I had my 8 year old help me and then he took it to school for show and tell.
542237
The three terrestrial classes that give rise to the four extra embryonic membranes are mammals, birds, and reptiles.\n\nThe four membranes are:\n\nChorion. The outermost of the two fetal membranes - the amnion is the innermost --. which together surround the embryo. The chorion develops villi (vascular fingers) and gives rise to the placenta. In Greek, the word "chorion" means "skin or leather."\n\nAmnion. The amnion is a membranous sac which surrounds and protects the embryo. It is developed in reptiles, birds, and mammals, which are hence called 'Amniota'; but not in amphibia and fishes, which are consequently termed 'Anamnia'.\n\nAllantois. An extra-embryonic membrane of reptiles, birds, and mammals arising as a pouch, or sac, from the hindgut. In reptiles and birds it expands greatly between two other membranes, the amnion and chorion, to serve as a temporary respiratory organ while its cavity stores fetal excretions. In mammals other than marsupials the allantois is intimately associated with the chorion, contributing blood vessels to that structure as it forms—in conjunction with the endometrium, or mucosal lining, of the uterus—the placenta. \n\nYolk Sac. A membranous sac attached to an embryo, providing early nourishment in the form of yolk in bony fishes, sharks, reptiles, birds, and primitive mammals and functioning as the circulatory system of the human embryo before internal circulation begins.