Test 5 Flashcards
Thomas Hunt Morgan
The 1st scientific support for chromosomal theory of heredity
An affected male (XdY)- Hemizygous
Gives disease allele to all daughters none to son
An affected female (XdXd)
Gives disease allele to both daughters and sons
An unaffected carrier female (XDXd)
1 healthy allele is enough; does not display disease
50% disease allele to either daughters or sons
Linked Genes
A bunch of genes on a chromosome close together & are inherited together
Unlinked Genes
On the same chromosome, behave as independent genes
Inversion of chromosome
structural rearrangement of a chromosome
Frederick Griffith Experiment
A heritable substance can be transformed into other organisms
Hershey & Chase Experiment
DNA is the genetic material not proteins
Meselson & Stale Experiment
DNA is replicated in a semi conservative manner
What was the first technique used to determine that DNA was a double helix
X Ray Crystallography
Chargaff’s Rule:
of A = # of T
# of C = # of G
Semiconservative Replication
Each daughter cell will have 1 old strand from the parent molecule and 1 new strand
Conservative Replication
1 daughter cell entirely new, the other entirely old
Dispersive Replication
All 4 strands have mixture of old and new
DNA Polymerase III
Add to the 3’ end ;
elongate 5’ —> 3’
Leading strand
single DNA strand is replicated in the 3’ to 5’ direction
Lagging strand
work away from the replication fork & a series of segments
Nuclease
DNA cutting enzyme
Nucleotide Excision Repair
- Detect damaged DNA
- Nuclease
- DNA Polymerase
- DNA Ligase
Telomerase
enzyme that lengthens telomeres in germ cells
DNA Helix
Negatively Charged Phosphate Backbone
Histones
Lots of positively charged amino acids, DNA wraps around
Interphase chromosome
attach to the nuclear envelope & maintain most of the packing
