Biology Chapter 16 Flashcards
What bacteria did Frederick Griffith work with in 1928?
Streptococcus
What did Frederick Griffith’s work with streptococcus Show?
A chemical could change harmless bacteria into pathogenic bacteria
Pathogenic means
Disease causing
Which strain killed mice?
The smooth strain
Which strain did not kill mice?
The rough strain
If Frederick Griffith mixed dead smooth bacteria with live rough bacteria what happened?
The mice died and had live smooth bacteria in them
Scientifically, how did the mice die?
The rough bacteria had absorbed DNA from the dead smooth ones, which changed the rough strain into the deadly smooth strain
When did Barbara McClintock show that genes are on chromosomes?
1941
In 1941 what did Barbara McClintock Show?
That genes are on chromosomes
When did Alfred Hershey and Martha Chase use viruses labeled with radioactivity to show that DNA is the genetic material?
1952
Alfred Hershey and Martha Chase used viruses labeled with radioactivity to show that
DNA is the genetic material
When did Rosalind Franklin, James Watson, and Francis Crick use X-Ray diffraction to work out the structure of DNA?
1953
Rosalind Franklin, James Watson, and Francis Crick used X-Ray diffraction to
Work out the structure of DNA
During interphase, before mitosis or meiosis, the DNA is copied inside the
Nucleus
When did Matthew Meselson and Franklin Stahl use bacteria to show that DNA replication was semi-conservative?
1957
Matthew Meselson and Franklin Stahl used bacteria to show
That DNA replication is semi-conservative
What does semi-conservative mean?
Each new pair of DNA strands contains one old strand and one new one
What is the first step of DNA replication?
The two strands of DNA separate
What is the second step of DNA replication?
Each strand acts as a template (or model) for a new DNA strand
What is the third step of DNA replication?
The enzyme DNA polymerase forms new DNA sections working from the 3’ (3 prime) end of the original DNA to the 5’ (5 prime) end
What is the fourth step of DNA replication?
DNA ligase joins together the Okazaki fragments
What is the fifth step of DNA replication?
Nucleus enzymes correct any mistakes in the DNA
When did Frederick Griffith work with bacteria?
1928
