Identical twins were separated at birth and brought together after 13 years. They varied in height by 5 centimeters and in weight by 10 kilograms. The most probable explanation for these differences is that (1) their environments affected the expression of their traits (2) their cells did not divide by mitotic cell division (3) they developed from two different zygotes (4) they differed in their genotypes

Research suggests that identical twins have many similarities, such as body weights, even as adults. A sample of ten sets of identical twins were weighed and had their weights recorded in kilograms. The researcher wishes to test whether there is a statistically significant difference in adult weight between first-born and second-born identical twins.Source: M. J. Tramo, W. C. Lodtus, T. A. Stukel, R. L. Green, J. B. Weaver, and M. S. Gazzaniga. “Brain Size, Head Size, and Intelligence Quotient in Monozygotic Twins.” Neurology 50, 1246–52.Given the design of the study and the question of interest, which one of the following computer outputs is relevant to use?

Which statement is true about identical twins? Group of answer choicesIdentical twins are very common.Somatic cells of identical twins contain different DNA.Identical twins start their life when two sperm cells fertilize two egg cells.Identical twins start their life when two sperm cells fertilize one egg cell.Identical twins start their life when early mass of dividing cells (originating from a zygote) splits in half.

The genetic similarity of identical twins isMultiple Choice100%.50%.75%.somewhere between 50% and 100%.

Two girls were born to the same mother, at the same time, on the same day, in the same month and the same year and yet somehow they’re not twins. Why not?

Why are identical twins useful for studying variation? They have identical genotypesThey are brought up in the same environmentThey have the same parentsThey have identical phenotypes