Tags & Description
extranuclear inheritance / cytoplasmic inheritance
inheritance patterns involving genetic material outside the nucleus
nucleoid
where genetic material of mitochondria and chloroplasts are located, can contain several copies of the chromosome
oxidative phosphorylation
main function of the mitochondria, a process used to generate ATP
genome
all the genetic material an organism possesses
euploidy
variation in the number of complete sets of chromosomes
aneuploidy
variation in the number of particular chromosomes, occurs through nondisjunction
trisomy
textra copy of all the genes, can express too much of the genes on this chromosome
monosomy
one less copy of all genes, can express too little of the genes on this choromosome
nondisjunction
occurs when homologs are pulled to the same pole or the centromere does not split
familial down syndrome
trisomy 21, chromosome 21 and 14 are fused together
deletion / chromosomal deficiency
occurs when a chromosome breaks and a fragment is lost
cri-du-chat
results from a deletion of a small terminal portion of the short arm of chromosome 5
gene family
consists of two or more genes that are derived from the same ancestral gene
homology
descent from a common ancestor
orthology
decent from a common ancestor by genome division
paralogy
descent from a common acestor by duplication within a genome
globin gene
encode subunits of proteins that bind oxygen, 14 paralogs on three different chromosomes
inversion
total amount of genetic information stays the same, linear sequence is rearranged
balanced translocation
formed by breakage and reunion of chromosomes, recombination between repeate sequences
reciprocal translocations
DNA gets swapped between non-homologous chromosomes or broken DNA's reactive ends created by breaks are recognized by repair enzymes and joined together
nonreciprocal translations / unbalaned translocations
the transfer of genetic material occurs in only one directio
robertsoninan translocation
fusion of two telocentric chromosomes in the centromere region
PAR
psuedoautosomal regions, critical to segregation of x and y chromosomes during male gametogenesis
MSY
male-specific region Y
SRY
sex-determining region y
TDF
testis-determining factor, triggers testes formation, binds DNA and regulates gene expression
psuedoautosomal inheritance
the very few genes found on both X and Y chromosomes, has gotten shorter in evolutionary time
polypoid
have multiple complete sets of chromosomes
monoploid set
basic chromosome set, from which all the other genomes are formed
autopolyploids
have all chromosomes in the polyploid sepcies derive from a single diploid ancestral
allypolyploids
comeplete sets of chromosomes from two or more different ancestral species, much more common
anitbiotics
chemicals that kill or inhibit the growth of bacteria, used to treat bacterial infections. will target different cellular processes to restrict bacterial growth
carbon-source mutatns
cannot utilize a particular carbon source (sugar) for energy
lac-
a mutant that lost the ability to break down and use the sugar lactose as its only carbon source
auxotrophic
unable to synthesize an essential nutrient
leu-
a bacterium that has lost the ability to synthesize the amino acid leucine
prototroph
synthesizes all essential compounds
antibiotic resistance
bacterium can grow in the presence of antibiotic that it was formerly sensitive to
rich / complete media
all nutrients are supplied
minimal media
has very few nutrients
selection
only the organism with the phenotype of interest grows -- live or die only
screening
all phenotypes will grow, but they will be different (ie. colony shape, color, growth rate, enzyme production)
conjugation
direct DNA transfer between a donor and recipient bacterium, requires interaction between bacterial cells
transduction
transfer of DNA from one bacterium to another via a bacteriophage
transformation
uptake of extracellular DNA released from dead bacterium, requires a receptor and competence factors
lederberg and tatum experiment
demonstrated genetic transfer by bacterial conjugation, bacteria were able to transfer DNA so all necessary nutrients are produced
pilus
how bacteria physically interact during conjugation
fertility factor / f factor
confers the ability to donate DNA (fertility) during conjugation
episome / plasmid
small, extrachromosomal circular piece of DNA that determines f factor, also contains genes for tranferring itself to cells that lack f factor
f+ cells
have the f factor, serve as donors (recipients become f+)
f- cells
lack f factor, act as recipients, can act as donors once converted to f+
plasmid
small circular pieces of DNA, contain one or more genes, replicate independently of the bacterial chromosomr plasmidse
r plasmids
confer antibiotic resistance
col plasmids
encode colicins that can kill neighboring bacteria
virulence plasmids
carry genes that turn bacterium into pathogenic strains
conjugative plasmids
plasmids which are transmitted via conjugation, also carry the genes requires for conjugation
tra & trb
play a role in a the transfer of DNA
hfr cells
high frequency of recombination, derived from f+ strains. act as donor strains, created when an f factor integrates into the chromosome. recipients of hfr strains do not become f+ or hfr (stay f-)
interrupted mating experiments
demonstrated that specific genes in an hfr strain are transferred and recombined sooner than others, used a map gene order on the chromosome based on their time-of-entry from a donor hfr strain into a f- recipient strain
f' plasmids
f plasmids excised along with some chromosomal DNA, recipient cells become f'
merozygote / merodiploid
partially diploid, seen in f' plasmids
bacteriophage
a virus that specifically attacks bacterial cells, composed of genetic material surrounded by a protein coat, can follow the lytic cycle, the lysogenic cycle, or both
virulent phages
only undergo a lytic cycle
temperate phages
can follow both lytic and lysogenic cycles
generalized transduction
any piece of bacterial DNA can be incorporated into the phage
transduction step 1
infection of the donor cell, gene can be inseted in phage particle (rare)
transduction step 2
infection of the recipient cell, gene combined with recipient genome
natural transformation
DNA uptake occurs without help
artificial transformation
DNA uptake occurs with the help of special techniques
competence factors
proteins that facilitate the binding, uptake, and incorporation of DNA into the bacterial chromosome
competent
cells that can take up DNA
helicase (DnaB)
unwinds the DNA helix as replication proceeds, travels 5' to 3'
ssDNA binding protein (SSB)
binds and protects ssDNA
primase
RNA polymerase which can synthesize a RNA primer for initiation, requires DNA template and ribonucleotide triphosphates
DNA polymerase 1,3
synthesize DNA, prooofread, involved in replication
gyrase
reduce increased coiling generated during unwinding
DNA polymerase 1
remove RNA primers, active on the lagging end, proofreads, synthesizes DNA to fill in gaps from primer removal
ligase
join the gap-filling DNA to the adjacent strand, joins 3'-OH with 5'-phosphate
temperature sensitive mutants
can survive at a low/permissive temperature, and will fail to grow at the nonpermissive temperature (which is higher)
oriC
origin of replication, where replication starts
DnaA box
a DNA sequence that is bound by the protein DnaA
DnaA protein
binds DnaA boxes and to each other, causes DNA bending --> separation of strands in the AT-rich region
DNA adenine methyltransferase (Dam)
methylates the A on both strands of GATC immediately after replication -- the parental strands are methylated but it takes several minutes for the daughter strands
exonucleases
cut DNA from an end