241 - 32, Cytoplasmic inheritance Flashcards
cytoplasmic organelles behave differently and DO / DO NOT not obey Mendelian rules.
do not
Mitochondria are organelles that use ______ to produce energy efficiently
oxygen
Mitochondria have their own _____
genomes (DNA)
The human mitochondrial genome encodes __ genes: __ ribosomal RNA genes, __, tRNA genes (for protein synthesis), and __ proteins for energy metabolism
37, 2, 22, 13
The majority of mitochondrial proteins are made from ______ genes.
nuclear
_________ theory - Mitochondria (and chloroplasts) were derived from a symbiosis of an anaerobic eukaryotic cell and an aerobic prokaryotic cell. Many features of mitochondria resemble those of bacteria.
endosymbiant
Mutations disrupting the energy production process will affect the growth on non- fermentable ______
sugars
________ petite: The transmission of the phenotype follows the Mendelian pattern. These mutations affect nuclear genes that contribute to energy production in mitochondria.
segregational
______ petite: The mutant mitochondria are “recessive” to the wild-type ones.
neutral
In neutral petite, the four meioses inherit some . . . (type) mitochondria to restore their ability to grow on non-fermentable sugars.
wild-type
________ petite: the mutant mitochondria are “dominant” to the wild-type ones.
suppressive
the inheritance of mitochondria is from . . .
the mother
Mitochondrial diseases usually exhibit the following features (3)
maternal transmission
variable penetrance
expressivity
_________ component: stored in eggs as mRNA, proteins, and organization
maternal
________ component: newly transcribed materials from the embryonic genome
zygotic
The effects of mutations in maternal-effect genes are manifested in the ______
progeny (not the mothers)
_____ are the disease-causing agents for spongiform encephalopathy, mad cow disease.
prions
_____ alter cellular phenotypes through self-perpetuating changes in protein conformation and are cytoplasmically partitioned from mother cells to daughter.
prions
prions are partitioned from _____ to _____
mother to daughter
prions are susceptible to _______
proteases
______ are resistant to UV and nuclease treatment
prions
In yeast, _______ petites mutants that show Mendelian behaviour and result from mutations in mitochondrial genes located in the nucleus.
segregational
In yeast, ______ petites, which are recessive genotypes and result from the complete absence of mitochondrial DNA.
neutral
In yeast, ________ petites, in which most of the mitchondrial DNA is lost (60-99%), though what remains is often amplified.
suppressive
________ ensure the proper segregation of genes during mitosis and meiosis
centromeres
Molecules that are not linked to chromosomes bearing nuclear centromeres behave differently during _______ and do not obey ______ rules
mitosis; Mendel’s
_________ are involved in producing energy for the cell through oxidative phosphorylation
Mitochondria
nuclear DNA is ______ and mitochondrial _______ (shape)
linear; circular
nuclear DNA cells contain ___ copies of DNA, mitochondria cells contain _____ copies of DNA
2; 1000s
endosymbiont theory suggesting mitochondria are bacteria was proposed by _____ _______
Lynn Margulis
there are >_____(#) genes in nuclear DNA, ___ genes in mitochondrial
> 30,000; 37
there are similar _____ compositions in membranes of bacteria and mitochondria (endosymbiont theory)
lipid
bacterial and mitochondrial genomes are ______ (shape) (endosymbiant theory
circular
bacteria and mitochondria have similar ____ (endosymbiant theory)
rRNA
In yeast, mitochondria are contributed by . . ., in humans . . .
yeast - both parents
humans - mother
Mutations in essential
mitochondrial genes, or nuclear genes that affect mitochondrial function, results in a
slow-growth phenotype on non-fermentable sugars (called _____)
petite
the high mutation rate of mitochondria suggests that the _____ mechanism IS / IS NOT as efficient as nuclear DNA
repair mechanism IS NOT
the high mutation rate of mitochondria suggests that there are many mutagenic ____ ________ around mitochondria
free radicals
yeast petite colonies are _____ than normal colonies
smaller
in segregational mutation in yeast petites the offspring will be . . .
1/2 petite, 1/2 normal
in neutral mutation in yeast petites the offspring will be . . .
all normal
in suppressive mutation in yeast petites the offspring will be . . .
all petite
myoclonic epilepsy and ragged red fiber disease is abbreviated . . .
MERRF
ataxia, deafness, dementia, and epileptic seizures are all due to . . .
MERRF (myoclonic epilepsy and ragged red fiber disease)
muscle fibers exhibit blotchy red patches resulting from the proliferation of aberrant (non-normal) _________ in what condition . . .
mitochondria; MERRF
in general, all the mitochondria in an individual are genetically _______
identical
________ - the existence of a uniform population of organelles within a cell or an individual
homoplasmy
________ - the existence of a variety of organelles within a cell or individual
heteroplasmy
proportion of mutant mitochondria determines the severity of the _____ phenotype
MERFF
HIGH / LOW energy requirement = least tolerant of mutant mitochondria
high
Tissues with LOW / HIGH energy requirements (e.g., skin) are only affected when the proportion of wild- type mitochondria is greatly reduced.
low
_______ component: stored in egg as mRNA, protein and organization
maternal
_________ (______) component: newly transcribed from the embryonic genome
embryonic (zygotic)
the _______ of the mother determines the inheritance of maternal effect genes
genotype
_____ diseases are called spongiform encephalopathies because of post mortem appearance of the brain large vacuoles in the cortex and cerebellum
prion
scrapie, TME, CWD, BSE (mad cow), CJ, GSS, FFI, Kuru all examples of _____ diseases
prion
______ resist inactivation by procedures that modify nucleic acids.
prions
UV treatment’s effect on prions (scrapie)
none
the infectious prion PrP^Sc similarities to PrP^C are . . .
exact same
knockout mice lacking PrP are resistant to ______
prions
In Saccharomyces cerevisiae, a cross between a haploid suppressive petite mutant and a haploid wild type results in petite diploid progeny. This is because of . . .
deletions in the mtDNA
nonfunctional mutant mitochondria proliferation advantage in ________ petite because there are deletions in the mtDNA
suppressive
The transmission of prion is sensitive to the treatment of
protease
The maternal-effect mutation torso (tor) is recessive. In the absence of the torso protein product, embryogenesis is not completed (missing both head and tail structures). Consider a cross between a female heterozygous for the torso (tor+/tor-) and a male homozygous
for the mutation (tor-/tor-).
all are normal
