Lyon Hypothesis and Cross-over

These two ideas are similar and different from one another for a variety of things.   The Lyon hypothesis, also called the X inactivation hypothesis, maintains that in the early embryonic development of a normal female, one X chromosome becomes inactivated in each body cell.   Chance is used to show which of the two X chromosomes is inactivated in a given cell.   Several kinds of evidence support this idea.   A Barr body is a darkly staining mass that contributes to this idea.


Cross-over is another idea that can compare and contrast.   It is an exchange of alleles between homologous chromosomes and it greatly increases the genetic variability that results from sexual reproduction.   If two genes are far enough apart, breaks between them are frequent.   This causes a cross-over in the chromosomes.   Some of the genes in Mendel's experiments assorted independently for this reason.   The frequency of these two linked traits gives a measure of the relative distance on the chromosome between the genes for those traits.   These two ideas are similar in the way that chromosomes are needed in their works.   But different by the styles and techniques that are used in the study.   The frequency with which two linked traits become separated gives a measure of the relative distance on the chromosome between the genes for these traits.   Genetic maps now exist for chromosomes of humans and many other organisms.   These traits and genes in both functions and types help explain a lot about these ideas.