mini test 2 Flashcards
What was beadle and tatums experiment
tested on mold to show that each gene encodes a specific enzyme
define gene
basic unit of inheritance
what is the coding region?
where the template for RNA (transcription occurs
what is an exon?
the coding region for gene that codes for protien
what is a intron?
non coding DNA transcript that get spliced out
what is chromatin
DNA wrapped around histone protiens
describe the central dogma
information is encoded into dna then transcribed into mRNA then translated into amino acids that code for protiens
describe the characteristics of a bacteria
- no membrane bound organelles
-circular DNA - translation and transcription occur in the same location
what does a promotor do?
promotor is found in the DNA of an operon and determines if the gene will be expressed or not based on environmental conditions
what is the trp operon?
no trp = the protein is produced
trp present = bonds to receptor which turns off the operon - this is so the cell doesnt have too much trp
describe gene expression in eukaryotes
for a gene to be expressed, histones either need to be unraveled or coiled tighter - histones attached to functional groups via covalent bonds can modify teh expression
Why is BASAL general transcription factors important?
they bind to the promotor on DNA to initiate transcription
what are enhancers and distal promotors
promotes high levels of expression
list different types of mutations
point mutation (deletion or insertion)
define a gamete
a haploid sex cell
define somatic cell
undifferentiated cell - 46 chromosomes
what are the steps of meiosis 1
pro - rna recombination and cross over occurs
met - spindles attach to centromere and they line up along the middle
ana - they are pulled to opposite polls
tel - the separate completely
cyt - they become 2 cells
what are different forms of genetic variation?
independent assortment, mutation, recombination
how do you do a test cross
f1 x P
what is the monohybrid ratio
3:1
what is the point of test crosses
infer the genotype from the phenotype - cross unknown individual with recessive homozygous
describe the process of the Lac operon
its the metabolic pathway for breaking down lactose
an absence of lactose = lac repressor is present (shuts does lac gene)
lactose present = repressor detaches and DNA polymerase binds to promotor to turn on lac gene
what is a positive regulator?
activators
what is a negative regulator?
repressors
what happens (in relation to lac operon) when there is no glucose in the system
cyclic AMP increases. this will bind to CAP (protein) then to the CAP receptor site = increased rates of transcription of lac gene
what are the 3 steps of PCR reactions
- denaturation: strands seperate
- annealing: primers attach
- extension: Taq polymerase incorperates base pairs to reform DNA
what will a taster mutation look like
more then 1 line due to cuts from restriction enzyme
what are the methods of DNA transfer between bacteria
- conjunction: direct cell contact
- transformation: incorperation of naked DNA
- transduction: transfer of chromosomal or plasmid DNA from cell to cell by bacterial viris
independent assortment vs law of segregation?
independent assortment: alleles of different genes assort into gametes
segregation: alleles of the same gene assort into different gametes
