4.1 The Search for the Molecular Basis for Life: 3 Foundational Experiments

DNA, DNA History

Which experiment is pictured?

Griffith experiment

Which experiment is pictured?

Avery, McCarty, MacLeod experiment

Which experiment is pictured?

Hershey and Chase experiment

Year of Griffith's Experiment: 1928, 1944, or 1952?

1928

Year of Avery, McCarty, Macleod's Experiment: 1928, 1944, or 1952?

1944

Year of Hershey and Chase's Experiment: 1928, 1944, or 1952?

1952

Which strain of Streptococcus pneumoniae bacteria is protected by an outer capsule and causes a deadly infection?

S strain

Which strain of Streptococcus pneumoniae bacteria lacks an outer capsule and is non-deadly?

R strain

What is bacterial transformation?

The process by which a bacterium takes up genes from other cells causing a change in its characteristics

If a mouse is injected with the R strain of bacteria, what happens?

The mouse lives

If a mouse is injected with the S strain of bacteria, what happens?

The mouse dies

If a mouse is injected with heat-treated S strain of bacteria, what happens?

The mouse lives

If a mouse is injected with a mixture of heat-treated S strain and R strain, what happens?

The mouse dies

Why did the combination of two strains of bacteria, both of which were harmless on their own, cause the results Griffith saw in his experiment?

The genetic molecule of the S strain bacteria was absorbed into the R strain bacteria and transformed the R strain into a deadly strain.

Which experiment involved injecting mice with R strain bacteria, S strain, heat-treated S strain, and a mixture of R + heat-treated S?

Griffith experiment

Which scientist(s) concluded that something can transform non-deadly bacteria into a deadly strain?

Griffith experiment

Which of the following molecules, when removed from a cell, eliminates the ability for bacteria to transform? Carbohydrate, DNA, Lipid, Protein, or RNA

DNA

Which scientist(s) concluded that if DNA in bacterial cells is destroyed then bacteria cannot transform.

Avery, McCarty, MacLeod

Which experiment used enzymes to denature different molecules in bacterial cells one at a time in order to determine which is used as the genetic molecule by bacteria?

Avery, McCarty, MacLeod Experiment

What is a bacteriophage?

A type of virus that infects bacterial cells

Which experiment used radioactive elements to label DNA and protein in bacteriophages, exposed the bacteriophages to bacteria, and analyzed the elements found in the bacterial cells to determine the molecule?

Hershey and Chase experiment

Which element is found in DNA but not in Protein?

Phosphorus

Which element is found in Protein but not in DNA?

Sulfur

If a bacteriophage infects a bacterial cell, which element can be detected inside the cell?

Phosphorus

If a bacteriophage infects a bacterial cell, which element can be detected in the fluid outside the cell?

Sulfur

Which scientist(s) concluded that viruses (and all living organisms) use DNA as their genetic material?

Hershey and Chase