Egg is a female ova (female gamete) which once fertilized becomes a fertilized egg.Each fertilized egg has an external protective membrane( hard shell in oviparous). Often two female gametes get fertilized and have a common protective membrane (hard shell in oviparous).This is why sometimes(rarely) an egg has two yolks inside.
You mean like Siamese twins? Yes it is possible but only with identical twins I think because they come from the same egg thing and the egg thing splits on two and if they haven't split in two entirely by the time the babies are born they are joined together =(
identical twins are single egg twins. fraternal twins a two egg twins. fraternal
I'm sure it may be possible to have twins at the time of feritilzation, but it is highly unlikely that two fetuses would survive in the same egg.
Birds do not have live young, they lay eggs. It is possible to get a double yoked egg, but I don't know whether they are viable or not.
Twins are identical because they come from the same egg.
if they are in one egg, the process can go on inside the egg. but if they are in two, it cant pass from egg to egg. basically it can only happen inside the egg.
Depends on how close you are. Twins from the same egg is usually closer and experiment same symptoms is not uncommon.
you get twins :)
How do fraternal twins form? Answer one egg from each ovary is fertilized.
Yes, it is very possible.
identical twins, as opposed to fraternal.
It depends on the type of twins If It was identical (monozygotic) twins, one egg is fertilized (As you can see, identical twins have similarity in phenotype (the observable characteristic of an organism) because of development of one zygote divided into two embryos) but if it was non-identical twins, two eggs or more (such as triplets or quadruplets) are fertilized. The twins have differences in phenotype