Problems Ch. 6: 16, 17, 18, 22, 25, 26
Genomes in bacteria
Most have a single, circular chromosome
Introns are rare; genes are densely packed
Many genes are arranged in operons, which
are a group of genes that are transcr
What is DNA?!
DNA is normally two strands arranged in a double helix.!
What is DNA?!
Hydrogen bonds hold the helix together!
DNA replication occurs continuously and discontinuously!
DNA polymerase adds
nucleotides to a 3-OH
at the replisome!
What is a mutation?!
A mutation is a heritable change in DNA sequence.!
Mutation produces genetic variation within populations.!
Mutation is the ultimate source of genetic variation for evolution. !
Norm of reaction
Relationship between genotypic and
environmental influences on phenotype
difference due to
One gene-one enzyme
George Beadle and Edward Tatum first
proposed the hypothesis
Lecture 10 Chromosome
Ch. 11 Problems: 1, 2, 4, 5 (a-b,e-g), 7, 8, 13, 18, 23.!
Bacterial Chromosomes Are Simple in
Bacteria have single chromosomes
that are almost always circular. !
Bacteria also carry multiple
copies of one
The farther apart genes are, the greater the
recombination frequency between them
r = 8%
Interpretation: 8 meiotic products out of 100 are recombinant
We say that genes C and D are 8 map units (m.u.) apart.
Or, genes C and D are
Transformation of Pneumococcus
1928 - Griffiths experiment
Transformation is the uptake of DNA from the environment.
Cells die and release DNA
into the environment; this
becomes the donor DNA
Gene regulation in prokaryotes!
Ch. 14: 2, 5-7, 12, 16 (a-d)!
Overview of gene expression regulation!
Some genes are expressed all the time, and some only when they are needed.!
Gene Regulation in Eukaryotes!
Ch. 15: 1, 2(b-e), 3, 4, 5 (a), 6, 10, 12!
Variegated forms of petunia
are caused by RNAi!
Overview of gene expression regulation in eukaryotes!
Interactions of regulatory proteins and
DNA for transcriptional reg
Problems Ch. 8: 1-3, 4(-c), 5, 7, 14, 22 !
Transmission of information!
process of copying information
from DNA to RNA!