Chapter 9 - Genetic Information Flashcards
Pangenesis
this theory stated that each part of the body produced tiny particles called pangenes or gemmules; proposed by Darwin in 1868
Pangenes
thought to be miniature replicas of each organ or tissue of the body
T.A. Knight
crossed two true-breeding lines of the garden pea
Law of Segregation
aka Mendel’s First Law of Heredity; alternative alleles segregate form each other in heterozygous individuals and retain their identity
Law of Independent Assortment
genes for color and shape assort independently of one another
Alfred Sturtevant
constructed the first genetic map in 1913
Replica Plating
designed to isolate auxotrophs; bacteria incubated on a master plate for set time, containing complete medium; auxotrophs and prototrophs grow on this plate, velvet stamp is used to replicate it exactly onto a replica plate
Epistasis
occurs between different pairs of genes; it does not occur between two members of an allelic pair
Pleiotropy
an individual allele has more than one effect on the phenotype
Aneuploidy
condition in which cell nuclei have an unbalanced set of chromosomes
Euploid
nucleus has normal complement of chromosomes
Klinefelter’s Syndrome
an XXY male offspring
Turner’s Syndrome
O gamete from females + X gamete from male = XO female
How do you differentiate between sex-linked versus an autosomal recessive disease?
If both sexes are equally affected, it’s likely autosomal. If males are affected almost exclusively, it is sex-linked. 1/4 of children should be affected in either case and both parents may also appear normal
How do you know if a disease is dominant versus recessive?
a person affected with a dominant genetic trait has one parent who is also affected
DNA Polymerase I
enzyme that catalyzes DNA formation, adds about 20 deoxyribonucleotide residues (dATP, dGTP, dTTP, and dCTP)
B-DNA
contains a major and minor groove, proteins that recognize specific DNA sequences can gain access to the DNA double helix via the major groove
A-DNA
minor groove essentially vanishes due to a specific puckering of the furanose ring
Taq DNA polymerase
stable at temperatures up to 90 degrees Celsius, does not denature at that temp
DNA gyrase
adds negative supercoils ahead of the advancing replication fork to make DNA separation easier
Helicase
binds to the ori site, catalyzes ATP-driven unwinding of duplex DNA
Primases
aggregate to form a primosome, RNA polymerase that synthesizes about 5 nucleotides of RNA that are complementary to one of the DNA templates
DNA polymerase III holoenzyme
catalyzes synthesis of 1000 phosphodiester bonds
DNA ligase
joins the free 3’-hydroxyl group of new daughter DNA
