Question

differentiate
(a) monozygotic twins (identical)
(b)dizygotic (fraternal)
(c)siamese (United)​

Answer 1

Answer:

1. Identical twins are also called monozygotic twins. They result from the fertilization of a single egg with a single sperm. And as those cells divide and multiply, at some point very early in embryonic growth they split into two individuals. So that you can imagine that the genetic material in these two identical twins is identical to each other, hence the name. The contrast to this would be fraternal twins, which are twins born at the same time. However, they are actually the result of fertilization of two different eggs, and thus can be different genders and look different, and have different characteristics. What's becoming increasingly clear is even though we call identical twins identical, and we think of their genetic material as being identical, we need to be reminded that there are environmental influences that may change, actually, the characteristics of identical twins, reminding us, as we already know, that even though identical twins come from the same genetic material, in characteristics they may actually have differences as well.
2. Dizygotic twin, also called fraternal twin or nonidentical twin, two siblings who come from separate ova, or eggs, that are released at the same time from an ovary and are fertilized by separate sperm. The term originates from di, meaning “two,” and zygote, “egg.” The rate of dizygotic twinning varies considerably worldwide. For example, parts of central and western Africa have very high twinning rates; studies in Nigeria have reported rates of more than 45 sets of twins per 1,000 births. By comparison, the rate in South and Southeast Asia appears to be as low as 6 to 9 per 1,000 births. While these figures concern all twin births (monozygotic and dizygotic), dizygotic twinning accounts for the majority—at least two-thirds—of them.

I don't remember the last one much

I hope you understand..