DNA / Genes / Cells

Is DNA same in all types of cells?
Is DNA same everywhere in the body?
Or there are some minor differences?


For the IMAT exam, all cells have the same DNA unless they don’t have a nucleus (such as RBCs) or sex cells.
So the questions you should ask yourself are

  1. Is it a sex/somatic cell
  2. Is there even genetic material in that cell
  3. Which type of cells is it

Hi Ari!

i have a question about mitochondrial DNA
i know it’s inherited only from the mother
does this means mtDNA is X linked? would sperm cells have mtDNA genes or are they removed in some way?

Thank you

Mitochondrial DNA isn’t X linked because it isn’t found on the X chromosome. It is entirely separate from regular DNA. X-linked refers to genes that we only found on the X chromosomes specifically.
Not for the IMAT: it was recently found that some mtDNA is inherited by the sperm to some extent (sometimes)
But for the IMAT, you get it from the egg’s mitochondria, which means only the mother can inherit the mitochondria from the egg, and then the mitochondria duplicate during the fetal development