Extranuclear inheritance, imprinting, & maternal effect 3 Flashcards
Mendelian inheritance patterns follow what three rules?
- The genes obey mendel’s law of segregation, except when rare mutation are present beacuse the genes are then passed unaltered from generation to generation
- The expression of the genes in the offspring directly influences their traits
- When crossing two or more genes they obey mendel’s law of independent assortment
Mendelian inhertiance involves _____________
Nuclear genes
Nuclear genes
Gene located on chromosome that are located in the nucleus
Extranuclear inheritance (Cytoplasmic inheritance)
Inheritance genes from organelles outside the nucleus (Ex. Mitochondria & chloroplast)
Nucleiod
Where the genetic material in the chloroplast is
_________________ produces non-mendelian results because the chloroplast & mitochondria are not sorted during meiosis & therefore dont segregate into gamtes
Extranuclear inheritance
Maternal Inheritance (Type of extranuclear inheritance)
When the phenotype is determined by the mother (The chloroplast & mitochondria has this because they are inhertied through the cytoplasm of the egg) (Breaks the law of segregation)
Can’t use a punnett square for extranuclear genes have to know what instead?
- Need to know if the offspring inherits a gene from the mother the father or both
- Need to know if heterplasmy (has both normal & mutant genes) is present in the parent (s) who transmit them
Mitochondria also follows ______________
Maternal effect
Many human disease are caused by ________________
Mitochondrial mutation
Endosymbiosis Theory
Believe that the chloroplast & mitochondria etc were formed from living inside another organelle
Epigenetic inheritance (Non-menelian pattern)
Modification occur to a nuclear gene/chromosome that alters its expression (Ex. X-chromosome inactivation)
Genomic imprinting (type of epigenetic inheritance)
Modifies nuclear gene that alters gene expression
The expression of an imprint gene depends on the _______ of the parent which the gene was inherited
Sex
______________ when a segment of DNA is marked & that mark is retained & recognized throughout the organism life
Genetic imprinting