Chapter 1 Flashcards
(23 cards)
common characteristics of model organisms
- Short generation time
- Production of numerous progeny
- Ability to carry out controlled genetic crosses
- Ability to be reared in a lab environment
- Availability of numerous genetic variants
- Accumulated body of knowledge about their genetic systems
complete set of genetic instructions for any organism
genome
is either RNA or DNA
genome
primary structure of DNA
Nucleotides
Secondary structure of DNA
- double helix
- hydrogen bond and base pairing
- antiparallel complementary DNA strand
chain of nucleotides
Nucleic acids
sugar + phosphate + nitrogenous base
Nucleotide
2 nucleotide types dependent on the sugar
RNA
DNA
enzyme responsible for adding and removing turns in the coil
topoisomerase
lightly packed chromatin, active in gene expression
Euchromatin
tightly coiled chromatin, inactive in gene expression
heterochromatin
What is heterochromatin involved in
- metabolic activity
- transcription
- cell division
- centromere
- telomere
proteins used to package and order DNA
Histone proteins
Chromosome structure
- nucleosome
- Chromatosome
High order chromatin structure
- 30 nm fiber
- 300 nm loops
- 250 nm wide fiber
C value
genome size
Key characteristics of genetic material
- must contain complex info
- must replicate faithfully
- must encode phenotype
- must have capacity to vary
proposes that mitochondria and chloroplasts were free living bacteria
endosymbiotic theory
Where is animal mtDNA inherited
almost exclusively from female parent
traits encoded by mtDNA
- petite mutations in yeast
- Neurospora mutations
- cytoplasmic male sterility
human diseases encoded by mtDNA
- MERRF
- LHON
- NARP
- KSS
- CEOP
evolution of mitochondrial DNA
- high mutation rate in vertebrate mtDNA
- # of genes & organization remains constant
- most copies of mtDNA identical
What is damage to mitochondrial DNA associated with?
Aging
