Chapter 15, Test 4

Question 1

what organelles contain their own genome

Answer 1

mitochondria and chloroplasts

Question 2

what do the chromosomes look like in mitochondria and chloroplast

Answer 2

circular DNA

Question 3

whats significant about the mito and chloroplast genome

Answer 3

encode their own rRNA and tRNA and have their own translation apparatus

Question 4

can the genes that mito and chloro encode for all development and function

Answer 4

no, need some from nucleus

Question 5

what mtDNA diseases affect

Answer 5

electron transport chain

Question 6

what specifically in ETC of mtDNA do diseases affect

Answer 6

ATP synthesis

Question 7

what is one hypothesis to aging

Answer 7

accumulation of mtDNA mutations

Question 8

what certain proteins are needed for mitochondria

Answer 8

for oxidative phosphorylation

Question 9

what certain proteins are needed for chloroplasts

Answer 9

photosynthesis

Question 10

how many bp would you see in cpDNA

Answer 10

120-200

Question 11

what RNA is most abundant in mtDNA

Answer 11

tRNA

Question 12

how are genes in mtDNA

Answer 12

tightly packed, no introns and no useless nucleotides

Question 13

what is RNA editing like in mitochondria

Answer 13

make premRNA into mature mRNA

delete or add uracils

Question 14

what are the exceptions for mitochondria to the universal code

Answer 14

carry own rRNA and tRNA,
N-formyl methionine and tRNA(met) initiate translation,
5 triplets are different than nucleus DNA, UGA not stop and AUA= met

Question 15

are there more genes in mito or chloro

Answer 15

chloroplasts

Question 16

does cpDNA contain introns

Answer 16

yes

Question 17

what is the endosymbiont theory

Answer 17

organelles represent remnants of free-living organism that est symbiotic relationship with proto-eukaryots

Question 18

what are examples of the endosymbiont theory

Answer 18

mito have double membranes, have bacterialike protein synthetic machinery, divide by binary fission

Question 19

what is biparental inheritance

Answer 19

obtain organelles from both parents

Question 20

what is uniparental inheritance

Answer 20

obtain organelles from one parents, mainly mom

Question 21

what is non mendelian inheritance

Answer 21

uniparental inheritance

usually through egg cytoplasm

Question 22

what is MERRF

Answer 22

high levels of lactate in blood, seizures, muscle atrophy, brain and cognitive degenration over time

Question 23

what causes MERRF

Answer 23

mutation in tRNA-lys in mito genome

translation of mito proteins affected and ATP production

Question 24

how is MERRF inherited

Answer 24

maternal

Question 25

why does MERRF show great variability in severity of expression

Answer 25

genetic heteroplasty

Question 26

what is heteroplasmy

Answer 26

contain both wildtype and mutant allele

expressivity based on number of mutant in cell

Question 27

how does threshold effect work with heteroplasmy

Answer 27

depends on fraction of wildtype and mutant genome copies

Question 28

how does heteroplasmy affect daughter cells

Answer 28

distributed randomly

mutant number in daughter cell and not every cell undergoes replication

Question 29

why are rates of mutation higher in mitochondria

Answer 29

high conc of free radicals due to oxidative phosphorylation, preferential replication of mtDNA carrying deletions, lower selection against new mutations

Question 30

if maternal genes contributing mRNA to oocyte are mutant then what happens to progeny

Answer 30

progeny may be affected by mutation

Question 31

what is the generation lag for maternal effect

Answer 31

one generation lag between genotype and phenotype

Question 32

does cytoplasmic inheritance follow mendelian rules

Answer 32

no

Question 33

what is the direct effect like in cytoplasmic inheritance

Answer 33

long term