Q: Are twins two offspring produced by the same pregnancy? ¶
A: Yes.
Q: Are twins formed after a blastocyst essentially collapses? ¶
A: Yes, and splitting the progenitor cells in half, leaving the same genetic material divided in two on opposite sides of the embryo.
Q: Are twins born weighing less than 5.5 pounds , while the average birth weight of a healthy baby should be around 6–8 pounds? ¶
A: Yes, This is largely due to the fact that twins are typically born premature.
Q: Is a twin fertilized by its own sperm cell? ¶
A: Yes.
Q: Are twins endangered by this condition? ¶
A: Yes.
Q: Is a twin not reabsorbed? ¶
A: Yes.
Q: Are twins common in many animal species? ¶
A: Yes, and including cats, sheep, ferrets, giant pandas, dogs, deer, marmosets, and tamarins.
Q: Is a twin endangered when the other zygote becomes cancerous? ¶
A: Yes, or molar.
Q: Were twins always two zygotes? ¶
A: Yes.
Q: Are twins now evaluated for surgery to attempt to separate them into separate functional bodies? ¶
A: Yes.
Q: Are twins analyzed for 506,786 single nucleotide polymorphisms known to occur in human population? ¶
A: Yes, and nalyzed for 506,786 single nucleotide polymorphisms known to occur in human populations.
Q: Are twins indeed mirror image? ¶
A: Yes.
Q: Was a twin miscarried but the other was able to be carried to term? ¶
A: Yes.
Q: Is a twin being diverted into the other twin? ¶
A: Yes.
Q: Are twins referred to as doppelgangers? ¶
A: Yes.
Q: Are twins genetically nearly identical and they are always the same sex unless there has been a mutation during development? ¶
A: Yes.
Q: Is a twin not head down a caesarean section is often recommended? ¶
A: Yes.
Q: Is a twin head first and the second is not? ¶
A: Yes.
Q: Are twins dizygotic? ¶
A: Yes.
Q: Are twins uniformly distributed in all populations around the world? ¶
A: Yes.
Q: Are twins head down a trial of vaginal delivery is recommended at between 37 and 38 weeks? ¶
A: Yes.
Q: Are twins epigenetic modification? ¶
A: Yes, and caused by differing environmental influences throughout their lives.
Q: Were twins monozygotic? ¶
A: Yes.
Q: Are twins also more common for older mothers? ¶
A: Yes, and with twinning rates doubling in mothers over the age of 35.
Q: Are twins born with different sexes it is because of chromosomal defects? ¶
A: Yes.
Q: Were twins both found to be chimeras and to share all of their maternal DNA but only half of their father's DNA? ¶
A: Yes.
Q: Are twins either dizygotic or monozygotic? ¶
A: Yes, Less common variants are discussed further down the article.