Test 3 Flashcards
(20 cards)
Define Pleiotropy
a gene that affects more than one phenotypic character
Define Epistasis
The phenotypic expression of a gene at one locus influencing the phenotypic expression of another gene at another locus
what is a quantitative characteristic?
A characteristic that is influenced by many genes (aka polygenic inheritance)
What influences phenotype?
Genes + Environment + Time
How do you do a testcross with an unknown genotype?
By crossing the unknown with a homozygous recessive genotype and assessing the offspring proportion
What is another term for heterozygote?
A hybrid
Define recombinant offspring
offspring that have phenotype combinations that are not present in the parents
What is the recombination frequency equation?
of recombinant offspring
————————————— x 100 =%
Total # of offspring
What does the recombination frequency percentage tell you?
If the percentage is 45% or lower, the genes are dependent. If the percentage is 46% or higher, the genes are independent
What do you need for mapping
The recombination frq. and willpower
Define Transcription
The process of making mRNA out of DNA
Define Translation
The process of turning mRNA into proteins and amino acids
What is the Central Dogma?
The flow of genetic information: DNA->RNA->Protein
What is a codon made of?
Three(ish) amino acids
What does ORF stand for?
“Open Reading Frame”
What is a promoter?
A section of DNA that tells the cell where to begin DNA transcription
What are the steps of transcription?
Initiation: Promoters signal RNA polymerase to connect and begin replication
Elongation: RNA polymerase moves “downstream”
Termination: Transcription goes until it hits a terminator and stops
What does UTR stand for?
“Untranslated Region”
Define mutation
A heritable change in the DNA sequence of a cell
What are the two main ways DNA mistakes are fixed?
Proofreading: Pol3 has a backspace button
Mismatch repair: MutS inspects DNA and signals it to get fixed if it notices mistakes
