Jan 21: note

v. Mutation:
a. -a change in DNA sequence may lead to change in phenotype
PKU-: lack of breakdown phenylalanine which then can't make tyrosine which can't make melanin
b. Mutation are Neither bad or good
—in many cases mutations are silent meaning there is no change in genes or traits causes by a mutation)

VI. Interactions bet. genes and the environment
a. Environmental influences on gene expression
i. Cuba libres and espadrilles
ex: Tanning
—in high UV exposure (sun, summertime, tanning), more mealanin genes are expressed to protect from UV
related muations

b. Pleiotropy: change in one gene lead to many diff. effects
i. Blue eyed white cats - cause by change in 1 gene
ii. The Russian Fox Farm experiment - Fox being dog took place in 4 generation
—breddings foxes for docility led also to changes in fur color, floppy ears, and curly tails (characters of domestic dogs)

I. Gene expression: how genes are turned on/off
How genes -> protein -> change in phenotype.
—beings transcribed and translated into a protein that contributes to the phenotype of an ogranism
II. overview of transcription
DNA to RNA copy
-properties of DNA- supercoiled so must be unwound to be transcribed
prokaryotes wound around self
eukaryotes wound around protein
when DNA unwound, the strands are separated, RNA polymerases than synthesize RNA strand. RNA sythesis stops and RNA polymerase falls off DNA.

a. rate of transription
70 bases/sec/bacteria
40 bases/sec/eukaryote

b. length of transcripts
max. 10e6 RNA bases (about a million)

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