November 27 Lecture Notes

November 27 Lecture Notes - Bio Lecture Notes November 27,...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Bio Lecture Notes November 27, 2006 Mutated – X-linked recessive gene = duchenne muscular Then there is Hemophilia A- this is also x-linked …this is due to the absence of something known as factor-A… (but you have to look this up in the book or online see it’s similarities with the other two) And Red-green colorblindness = 6% x-chromosomes have this gene. And also, 6% of the males in the population at red-green color blind. There is a problem created because of the x-chromosome It is called dosage compensation problem - (each gene that one has is a dose of that gene….) what happens is that females have two doses of the x chromosome gene, but the males have one dose. Having too many could cause metabolic disarray. And to few would also have a similar problem. Everyone solves it differently. One way to solve the dosage compensation problem is by making the x-chromosomes (in fruit flies) work twice as hard as the two in females In humans….there is a rule known as single ACTIVE X CHROMOSOME What happens is when there are a limited number of cells, 8 to 16 cells; each cell would inactivate one of its two x-chromosomes and keep the other one active. The one that is inactive, would be coiled up next to the nuclear membrane (when a chromosome is coiled up it can not direct the activities of the cell). The active one is in its normal position. The one that is inactive is known as the
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

November 27 Lecture Notes - Bio Lecture Notes November 27,...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online