Chapter Seventeen: Organellar Inheritance Flashcards
organelle genomes lead to ___ inheritance
non-mendelian
four-o’clocks inherited variegated leaves from the ___ due to genes found on the ___ genome
mother
chloroplast
___ and ___ are nonnuclear organelles with their own small genome
mitochondria and chloroplast
mitochondria produce ATP through the ___ and ___
Krebs cycle and oxidative phosphorylation
the human mitochondria genome has ___ genes that encode for ___, ___, and ___
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tRNAs, rRNAs, and proteins for oxidative phosphorylation
a gene on mitochondria that encodes ___, which makes chemicals that are part of the inflammation response
gene: COX
encodes cyclooxygenase
a network of circular DNAs inside a mitochondrion including maxicircles and minicircles
kinetoplast
maxicircles contain ___but the sequence does not exactly match ___
genes
corresponding cDNAs
alters pre-mRNA sequence to make a mature RNA
RNA editing
RNA editing adds ___ and ___ and changes many ___
start and stop codons
new codons
minicircles encode ___
guide RNAs
___ use guide RNAs as templates for RNA editing
editosome
is the mitochondrial genetic code the same as the nuclear genetic code
no, 5 differences in humans
in corn, each leaf cell has ___ chloroplasts
40-50
function of chloroplasts
capture solar energy and store it in chemical bonds of carbs
most chloroplast genomes are ___ long
120-160kb
how many genomes are present in each chloroplast
more than one
chloroplast genomes have ___ gene arrangement and they ___ have introns
compact
do
___, ___, and ___ forms of chloroplast genome
circular, linear, and branched
chloroplasts have ___ genes that mitochondria
more
the use of a gene gun to make transgenic chloroplasts
biolistic transformation
DNA shot into the cell with a gene gun can enter ___ and __
chloroplasts
recombine into the genome
transgenic cells are selected for using a ___, and transgenic cells can be cultured to produce a ___
selectable marker
transplastomic plant
a transplastomic plant is one that contains ___
transgenic chloroplasts
mitochondria and chloroplasts require ___ to assemble and function
nuclear genome products
___ functions in mitochondrial electron support
cytochrome oxidase C
cytochrome oxidase C has ___ subunits: ___ from mitochondrial genome, and ___ by nuclear genes
7
3
4
nuclear genes encode the majority of proteins required for ___ in mitochondria and chloroplasts
gene expression
mitochondria and chloroplasts have characteristics of ___
prokaryotic cells
theory that mitochondria and chloroplasts are descended from bacteria that fused with nucleated cells
endosymbiont theory
mitochondria and chloroplasts:
have their own ___
mtDNA and cpDNA are not arranged into ___
mitochondria use ___ and ___ in translation
___ block mitochondrial and chloroplast translation
comparisons of rRNA suggest their genomes derive from a common ancestor of ___
DNA
nucleosomes
N-formyl methionine and tRNAfmet
inhibitors of bacterial translation
nonsulfur and cyanobacteria
some genes that originated in organelles have likely moved to the ___
nucleus
because some of those genes have moved into the nucleus, organelle copy becomes ___ and changes may make it ___
redundant
non-functional
organelle diversity can come from ___
different organelle genes being transferred to the nucleus in different lineages
the chloroplast genome is ___ than mitochondria but has ___ genes
smaller
more (twice)
progeny obtain organelles from both parents
biparental inheritance
progeny obtain organelles from just one parent
uniparental
when uniparental inheritance occurs, progeny most often inherit their organelles from the ___
maternal parent
mtDNA is ___; cpDNA is ___
mitochondrial DNA
chloroplast DNA
mtDNA mutations may result in ___ leading to ___ or ___
slow cell growth
small cell colonies or weak tissues
cpDNA mutations may ___ leading to ___
decrease chlorophyll production
change in leaf color
DNA polymorphisms can be followed by ___
DNA sequencing
humans get all mitochondria from the ___
egg (mother)
Mary and Herschel Mitchell isolated a slow growing mutant ___ strain that they called ___
Neurospora
poky
poky is a ___ gene
mitochondrial
when a poky female was crossed with a wild-type male mating cell, spores were ___
all poky
when a wild-type female was crossed with a poky male mating cell, spores were ___
all wild-type
female gamete may be ___ than male gamete, so the zygote receives ___ female organelles and ___ paternal organelles
much larger
many
few
paternal organelles may be actively ___ or ___
excluded or destroyed
paternal cells may segregate into ___
non-embryonic cells
___ may prevent organelles from entering the egg
fertilization
variegated four’o’ clock plants have ___, ___, and ___ branches
green, white, and variegated
the plant is variegated because it has ___
two types of chloroplasts
wild-type cpDNA makes ___, mutant cpDNAs prevent ___
chlorophyll
chlorophyll production
contain a mixture of organelle genomes
heteroplasmic cells
contain only one type of organelle genome
homoplasmic cells
mitotic progeny of homoplasmic cells are also ___
homoplasmic
mitotic progeny of heteroplasmic cells can be ___, ___, or ___
heteroplasmic, homoplasmic wild-type, or homoplasmic mutant
eleven distribution of organeller genomes has ___
distinct phenotypic consequences
and individual organelle can be ___ or ___ for either wild-type of mutant because each organelles contains ___ of the genome
homoplasmic or heteroplasmic
multiple copies
a certain fraction of wild-type organelles is sufficient for the normal phenotype
threshold effect
in four-o’ clocks, heteroplasmic cells make enough chlorophyll to ___
be green
several diseases of the ___ and ___ are caused by mutations in the mitochondrial genome
human nervous system and muscular system
mitochondrial mutations are passed from ___ to ___
mothers to children
symptoms of mitochondrial mutations vary due to ___
heteroplasmy
if a mother is affected by a mitochondrial disease, ___
all her children will be affected
flaws in mitochondrial electron transport chain lead to optic nerve degeneration and blindness
levers hereditary optic neuropathy (LHON)
MERRF shows a ___ pattern of inheritance
maternal
MERRF stands for ___
myoclonic epilepsy and ragged red fiber disease
MERRF is caused by mutations in ___
mitochondrial tRNAs
individuals affected by MERRF are ___
heteroplasmic
severity of MERRF depends on ___
percentage of mutant mtDNA
tissues with higher energy requirements are ___ tolerant of mutant mitochondria
less
tissues with lower energy requirements are affected by mitochondrial mutations only when ___
the proportion of wild-type mitochondria is greatly reduced
___ system in mitochondria generates free radicals, which can ___
oxidative phosphorylation
damage DNA
accumulation of mtDNA mutations over time may result in age-related decline in ___
oxidative phosphorylation
percentage of heart tissue with mitochondrial deletions ___with age
increases
brain cells of people with Alzheimers have abnormally low ___
energy metabolism
___ of mitochondria in most Alzheimers patients have mutations in cytochrome oxidase C
20-35%
oocyte nuclear transplantation can sidestep ___ of mitochondrial disease
transmission
the removal of nuclei from donor eggs with normal mitochondria then replacement of that nuclei with the nucleus from an egg of the mother with a mitochondrial disease
mitochondrial gene therapy
eggs resulting from mitochondrial gene therapy are ___
cybrids (cytoplasmic hybrids)
