biology EXAM #4 pt. 1 Flashcards
Hereditary information is… using…
It is the DNA program:
Is encoded in the chemical language of DNA and reproduced in all the cells of your body (using C, G, T, A nucleotides)
That directs the development of many different types of traits (phenotypes)
Early in the 20th century the identification of the molecules of inheritance loomed as a:
T.H. Morgan et al. suggested that genes are located in :
Not clear yet if ____ or _____ is the genetic material
major challenge to biologists
chromosomes
DNA or Protein
The role of DNA in heredity was first worked out by:
Evidence That DNA Can Transform Bacteria:
Frederick Griffith was studying Streptococcus pneumoniae
A bacterium that causes pneumonia in mammals
He worked with two strains of the bacterium
A pathogenic strain and a nonpathogenic strain
studying bacteria and the viruses that infect them
Griffith in 1928, found that when he mixed heat-killed remains of the pathogenic strain with living cells of the nonpathogenic strain, some of these living cells became pathogenic
They called it transformation (what is transformation?)
Avery and colleagues in 1944, announced that the transforming agent was DNA.
Additional evidence for DNA as the genetic material
Came from studies of a
(now known as change in genotype and phenotype due to the assimilation of external DNA by a cell)
virus that infects bacteria
Viruses that infect bacteria:
Are widely used as tools by
bacteriophages
researchers in molecular genetics
names
Performed experiments showing that DNA is the genetic material of a phage known as T2 phages
They knew that T2 and other viruses contain primitive DNA and protein
Used E. coli as T2 producing factories
Alfred Hershey and Martha Chase
Prior to the 1950s, it was already known that DNA
Is a:
, each consisting of three components:
que letras van juntas
polymer of nucleotides
a nitrogenous base, a sugar, and a phosphate group
G ≡ C and A=T
