BIOL 241 - Final Exam Actual study set
with Questions and correct/verified
Answers
basis of organelle genetics - ANSW-molecules that are not linked to chromosomes with nuclear
centromeres behave differently during mitosis; do not obey Mendel's rules
-organelle chromosomes
-DNA / RNA plasmids
-protein/mRNA
mitochondrial dysfunction is linked to - ANSW-neurodegenerative disorders (ex: parkinsons)
what causes Parkinson's disease? - ANSW-loss of dopaminergic neurons
mitochondria - ANSW--produce energy using oxygen; lots in muscle cells
-contain own small genome of ~17,000 bp circular DNA (about 37 genes)
-encodes 2 rRNAs and 22 tRNAs for protein synthesis (13 proteins for energy metabolism)
-99.9% of mitochondrial proteins are encoded by nuclear genes
human nuclear DNA - ANSW--linear
-3x10^6 kbp
-cell contains two copies of each gene
-encodes all cellular functions, including mitochondrial
mitochondrial DNA - ANSW--17 kbp
-circular
-37 genes
-cell contains 1000s of copies
-encodes only mitochondrial functions
endosymbiont theory - ANSW-an anaerobic cell engulfed an aerobic bacteria, and the two cells
developed a symbiotic relationship; with time, most bacterial genes ended up in the nucleus but a few
remained in what became the mitochondria
evidence for endosymbiont theory - ANSW--similar lipid compositions in membranes of bacteria and
mitochondria
-bacterial and mitochondrial genomes circular and lack associated histones
-protein synthesis in bacteria and mitochondria similar
, -rRNAs similar in bacteria and mitochondria
petite phenotype - ANSW-a slow growth phenotype that occurs when there are mutations in essential
mitochondrial genes or nuclear genes that affect mitochondrial function
why does mitochondrial DNA have a high mutation rate? - ANSW--repair mechanism not as efficient as
nuclear DNA
-lots of mutagenic free radicals around
three modes of inheritance of petite mutations - ANSW--segregational
-neutral
-suppressive
segregational inheritance - ANSW-haploid petite x haploid normal
->
normal diploid zygote forms
->
sporulation, meiosis results in 1:1 ratio of petites and normals
*occurs from mutation in nuclear gene involved in mitochondrial function
neutral inheritance - ANSW-haploid petite x haploid normal
->
normal diploid zygote forms
->
sporulation, meiosis results in all normal ascospores
*occurs from mutation is mitochondrial gene affecting mitochondrial function
suppressive inheritance - ANSW-haploid petite x haploid normal
->
petite diploid zygote forms (usually)
->
sporulation, meiosis results in all petite ascospores
*deletion that inactivates mitochondrial function but gives mutant mitochondrial proliferation
with Questions and correct/verified
Answers
basis of organelle genetics - ANSW-molecules that are not linked to chromosomes with nuclear
centromeres behave differently during mitosis; do not obey Mendel's rules
-organelle chromosomes
-DNA / RNA plasmids
-protein/mRNA
mitochondrial dysfunction is linked to - ANSW-neurodegenerative disorders (ex: parkinsons)
what causes Parkinson's disease? - ANSW-loss of dopaminergic neurons
mitochondria - ANSW--produce energy using oxygen; lots in muscle cells
-contain own small genome of ~17,000 bp circular DNA (about 37 genes)
-encodes 2 rRNAs and 22 tRNAs for protein synthesis (13 proteins for energy metabolism)
-99.9% of mitochondrial proteins are encoded by nuclear genes
human nuclear DNA - ANSW--linear
-3x10^6 kbp
-cell contains two copies of each gene
-encodes all cellular functions, including mitochondrial
mitochondrial DNA - ANSW--17 kbp
-circular
-37 genes
-cell contains 1000s of copies
-encodes only mitochondrial functions
endosymbiont theory - ANSW-an anaerobic cell engulfed an aerobic bacteria, and the two cells
developed a symbiotic relationship; with time, most bacterial genes ended up in the nucleus but a few
remained in what became the mitochondria
evidence for endosymbiont theory - ANSW--similar lipid compositions in membranes of bacteria and
mitochondria
-bacterial and mitochondrial genomes circular and lack associated histones
-protein synthesis in bacteria and mitochondria similar
, -rRNAs similar in bacteria and mitochondria
petite phenotype - ANSW-a slow growth phenotype that occurs when there are mutations in essential
mitochondrial genes or nuclear genes that affect mitochondrial function
why does mitochondrial DNA have a high mutation rate? - ANSW--repair mechanism not as efficient as
nuclear DNA
-lots of mutagenic free radicals around
three modes of inheritance of petite mutations - ANSW--segregational
-neutral
-suppressive
segregational inheritance - ANSW-haploid petite x haploid normal
->
normal diploid zygote forms
->
sporulation, meiosis results in 1:1 ratio of petites and normals
*occurs from mutation in nuclear gene involved in mitochondrial function
neutral inheritance - ANSW-haploid petite x haploid normal
->
normal diploid zygote forms
->
sporulation, meiosis results in all normal ascospores
*occurs from mutation is mitochondrial gene affecting mitochondrial function
suppressive inheritance - ANSW-haploid petite x haploid normal
->
petite diploid zygote forms (usually)
->
sporulation, meiosis results in all petite ascospores
*deletion that inactivates mitochondrial function but gives mutant mitochondrial proliferation
