Can two or more sperm cells fertilize one egg? What would happen if it did, and if it can't, why not?

Question

I am pretty sure of the answer, but I need a explained answer for school stuff. Anyone want to help me?

Answer 1

Ok, here's what we learned in biology (genetics).

If 2 eggs are fertilized by 2 sperm then you can have fraternal twins. If 1 egg is fertlized by 1 sperm and then divides, you get identical twins.

So basically, only 1 sperm per egg. If in the rare event that 2 got in there, I doubt anything would happen because an egg can't be fertilized twice and survive.

Answer 2

Fertilization is the process where two gametes fuse to form a single zygote. Gametes, such as sperm and egg cells, are haploid, meaning they have only half the normal number of chromosomes. The combination of one sperm and one ovum creates a zygote with a full, diploid set of chromosomes.
Triploid babies have 69 chromosomes instead of the normal 46. While triploidy is believed to occur in 1 to 2 percent of all conceptions, such pregnancies usually result in spontaneous miscarriage or still-birth before reaching full term.

In 2007, Time Magazine reported on a pair of twins who were apparently the result of an egg fertilized by two different sperm. The resulting twins were identical on their mother's side, but only shared half of their
father's DNA. While scientists are uncertain about the exact mechanism that occurred, they believe the triploid zygote must have divided into two separate zygotes after fertilization. This same division occurs in the development of identical twins, only in this extraordinary case, each new cell somehow managed to shed the superfluous genetic material, resulting in two diploid zygotes.

Answer 3

Yes, it's rare, but two sperm can fertilize one egg.

From http://baby2see.com/multiples/twins.html

"Semi Identical Twins
The 'semi-identical' twins are the result of two sperm cells fusing with a single egg, before becoming two embryos. An embryo created this way doesn't usually survive, but a few cases are known. Most of the time it goes totally unnoticed, and only shows up either if the two eggs have different genetic genders and the baby ends up with a mix of male and female gonads, or if it happens to be picked up on a genetic test that's done for other reasons (ex. paternity tests)."

Answer 4

So, this event is INCREDIBLY rare and unlikely. There is only one case of twins born who shared the same maternal genetic information, but differing (same father) paternal information - implicating the same egg used for the pregnancy. The only way this can occur is that when an ova is maturing it casts off polar cells that are smaller then the remaining ova in the process of meiosis - and somehow there were two viable eggs with identical genetic information in them that were subsequently fertilized by different sperms. As is what usually happens with fraternal twins, with the exception that fraternal twins come from different ovas and sperm.

I can't find the article on the polar body twins that were discovered earlier this year, but its out there somewhere.

So, in some ways - no, sperm can not fertilize one egg - it would result (if this did occur) with the kind of trisomy that would kill the zygote pretty quickly (with 69 chromosomes, its not viable). You should have a fair grasp of the calcium channel cascade that occurs after the sperm head enters the ova - it immediately shuts down anything passing through the ova's cell walls for many hours after that.

Answer 5

2 sperm can get to 1 egg BUT it will not result in twins.
the egg contains half the chromosomes to make a baby the sperm the other half (so 23 each to give a baby with 46 in total) if 2 sperm get there then there will be too many chromosomes and the "baby" will not develop. Usually it will form into a "molar" pregnancy. either way it just won't work....
twins need 2 eggs, 2 sperm 1 for each egg, (fraternal twins) or 1 egg 1 sperm but it then splits to produce identical twins....

Answer 6

Oh my goodness, how funny!! Not your question, other peoples answers. Eggs do not split until they are fertilized. Yes, two sperms can fertilize one egg at the same time. But this is really rare. It does NOT result in twins or anything. Most likely the egg will die. I'm not sure why, but you should do that research on your own.

Edit: It's known as a partial mole pregnancy.

Answer 7

I think 2 sperm can't separately fertilise. One of them will have technically been "first" albeit only small fractions of a second ahead of the other one. This first one will trigger the chemical reaction that will prevent any further sperm penetrating the ovum cell wall. (I think a triploid zygote [ the other answer] is formed when a double headed sperm fertilises an ovum.)

Answer 8

ok 2 sperm cannot fertilize one egg you think the mommy who did your second answer would know that. this is because when a sperm enter the egg the egg makes a seal preventing any further sperm from getting through, eggs do not split into 2 before they are firtilized like your 4th answer says "eggs can split and be fertilized by 2 sperm" this is not true 1 sperm firtilizes 1 egg then the egg can split creating indetical twins. non identical twins are when 2eggs are released an firtilized then by 2 sperm (1 sperm for each egg) i hope this explains things for you. also a woman can release 2 eggs and if she has sex with 2different men at this time each man can firtilized one of those eggs (2 babies with different dads born at the same time) that is less well known but i asure you its true you can even look it up online. i hope this helps you

Answer 9

Yes it is possible and it happened to my mom. 2 years after my brother. We always refer to it as the grape in the family. (Just bc that is what it looked like) my mom carried it to 4 months at which time she miscarried it. IT was basically a small mole with a few hairs, fingernail and the start of a tooth. She was told not to get pregnant for at least a year after because she would not only be subseptible to it happening again it would also give her a higher chance of getting cancerous cells. Of course this was back in 1980 when they knew less than they do now.

Answer 10

Usually only one sperm can enter the egg, then, immediately after that sperm gains access, the egg emits chemicals that prevent more sperm from entering after it.

IF two sperm enter (which almost never happens), the egg cannot survive. There is the wrong amount of genetic material and the egg almost immediately dies. It will never develop into a fetus.

Twins result from either two separate eggs being fertilized by two separate sperm (fraternal twins), or, one egg and one sperm unite and split into two shortly after conception (identical twins).