More on twins

I hope you have found the text of Module 3, Parallel Lives, informative and  thought-provoking. However, our discussion about twinning left us with some unanswered questions, such as whether the ability to produce twins is hereditary. Today I suggest that you skim through an article on the topic,  How Twins Work, 

and find answers to the following questions:

What differences between the “Jim twins” were discovered during the study?

What is a singleton?

What are two basic types of twins?

What is the ratio of monozygotic to dizygotic twins?

Where does the world’s largest annual gathering of twins take place?

What is vanishing twin syndrome?

What are conjoint twins?

Can twins have different biological fathers?

What is the birthrate of identical twins?

What factors influence the chances of having twins?

Has the birthrate of twins been changing over time?

Does the rate of twinning depend on the ethnic origin or race of women?

Women of what origin are the least likely to have twins?

What is cryptophasia? Why does it happen?