Embedded Files
Mitochondrial and Chloroplast Inheritance
Mitochondria and chloroplasts evolved from prokaryotes millions of years ago and still share some characteristics with them
Plasmid
Mitochondria with DNA
Mitochondria with DNA
Chloroplast with DNA
Chloroplast with DNA
Mitochondria
Mitochondria
Mitochondria and chloroplasts (and the genes they carry) are randomly distributed to daughter cells during mitosis and meiosis. When the cell divides, the organelles that happen to be on opposite sides of the cleavage furrow or cell plate will end up in different daughter cells 3. Single-parent inheritance. (Uni-parent inheritance). They do not follow simple mendelian rules because not inherited on nuclear chromosomes. In animal cells the egg contributes 23 nuclear chromosomes and all the organelles including the mitochondria (the sperm contributes 23 nuclear chromosomes).
Mitochondrial Inheritance
Mitochondrial Inheritance
Conditions caused by a mutation in the mitochondrial DNA have unusual patterns.
both males and females are affected
the condition is transmitted through the female to her offspring
if a male has the trait and his spouse doesn’t, their offspring won’t have the trait
In the first pedigree, you will see that when a female has the trait, all of her offspring have the trait, but in the second pedigree, this is not necessarily the case. The expression of mitochondrial conditions is variable. Inside each cell, there are several mitochondria. The number of mitochondria that carry the mutation can vary. A certain proportion of mutant mitochondria within a cell can be tolerated and the disease will not be expressed in the organism. A larger proportion of mutant mitochondria, however, may cause the disease to be expressed in the organism.
The first pedigree shows how inheritance is transmitted through the female, in the cytoplasm of her egg cell. The second pedigree shows how the expression can vary depending on the proportion of mitochondria carrying the mutation.
Page updated
Report abuse