extranuclear inheritance and imprinting Flashcards
where is extra-nuclear DNA locates in mammalian cells
mitochondria
what type of inheritance os observed with extra-nuclear DNA?
cytoplasmic inheritance (extranuclear inheritance)- traits are inherited through genes that are not in the nucleus
mono allelic expression is associated with which of the following
genomic imprinting- expression of a gene depends on whether it is inherited from the male/female parent
heteroplasmy
mix of wild-type and mutant in cells
heteroplasmy is associated with inheritance patterns involving ____ and why?
chloroplasts because they randomly distribute to daughter cells and due to the way it separates during meiosis
the symbiotic relationship where one organism lives inside another species is called
endosymbiosis- mitochondria and chloroplast originated from bacteria that took up residence within a primordial eukaryotic cell
G and g are dominant and recessive alleles respectively, for a gene. If a mating of an egg female with a Gg male resulted in the offspring with all the recessive phenotype, this would most likely be na example of
maternal effect gene- genes involved with genotype of mother that controls offspring phenotype
what term refers to the situation where a male parent may occasionally provide mitochondria via sperm
paternal leakage- occurs when DNA of sperm leaks in zygote during fertilization
the igf2 is maternally imprinted in mammals. If a female mouse that is homozygous for the mutant igf2 allele is mated to a male who is homozygous wild-type for igf2 then the progeny will be _____
100% wildtype
chromosome of mitochondria and chloroplasts is composed of
single-circular double-stranded DNA
main function of chloroplasts
photosynthesis
mtDNA
genetic material in mitochondria
paternal leakage
mitochondria provided through the sperm
human mitochondrial disease mechanism spread by
- transmitted from mother to offspring via the egg
2. mutations can occur in somatic cells during aging
theory of endosymbiosis
mitochondria and chloroplasts originated from bacteria that took up residence within a primordial eukaryotic cell
epigenetic inheritance
modification to a gene that changes gee expression, but is not permanent over the course of generations
genomic imprinting
expression of a gene depends on whether it is inherited from the male or the female parents
mono allelic expression
offspring express either the maternally-inherited or the paternally-inherited allele but not both
three stages of imprinting
- establishment of the imprint
- maintenance of the imprint during embryogenesis
- erasure and reestablishment of the imprint in the germ cells
maternal effect inheritance
only the genotype of the mother controls phenotype of offspring, due to accumulation of gene products that the mother provides to her developing eggs
maternal effect genes
encode RNA and proteins that play important roles in early steps of embryogenesis
mendelian inheritance
an inheritance pattern that follows the laws of segregation and independent assortment in which either parental gene segregates into gamete
sex-linked inheritance
trat in which genome is located on sex chromosome
paternal inheritance
transmission of any attribute from a father his offspring
ribosomes
molecule with RNA and proteins
nuclear genes
gene where DNA is located in cell nucleus
mitochondrial inheritance
inherited from female parent via egg cells
paternal effect genes
casual effect of the parents phenotype on the offsprings phenotype over effects of genes inherited from parents
recessive lethal gene
alleles both present in an organism that ultimately results in death
