Module 8 Test Prep

In 1869, DNA was discovered within the nuclei of cells. By the 1940s, scientists knew that chromosomes were made of both DNA and protein but did not know which was the genetic material of cells. In the 1950s, scientists demonstrated that DNA is the material responsible for heredity. In 1953, using information collected by other scientists, an American biologist and an English physicist built a three-dimensional model of DNA. These discoveries best illustrate the importance of —

• recent improvements in the scientific method

• independent research

• replication of results

• collaborative efforts among scientists

Using radioactively labeled bacteriophages, Hershey and Chase determined conclusively that —

• DNA cannot be the molecule that contains the genetic information

• DNA is the molecule that contains genetic information

• protein is the molecule that contains the genetic information

• DNA and protein both contain the genetic information

Which scientist is credited with developing the first “picture” of DNA using X-ray crystallography?

• Rosalind Franklin

• James Watson

• Erwin Chargaff

• Francis Crick

Because of complementary base pairing, the amount of —

• cytosine equals the amount of thymine

• adenine equals the amount of thymine

• guanine equals the amount of thymine

• guanine equals the amount of uracil

The Adenine and Guanine are represented by number —

• 1

• 2

• 4

• 5

The item labeled number 1 represents —

• a phosphate group

• a sugar

• a nitrogen base

• an adenine

What is represented by figure X?

• Chromosome

• Nucleus

• Gene

• DNA

What led to the understanding of complimentary base-pairings in DNA?

• The studies on the amounts of DNA bases in different organisms

• The observation of X-ray photographs of a cell mitochondria

• The research on RNA pairings in different organisms

• The evaluation of mitosis stages in the same species

What famous model was created after the events shown in the timeline?

• DNA

• Cell

• Evolution

• RNA

In 1950, Erwin Chargaff discovered that the percentage of adenine in DNA equals the percentage of thymine, and that the percentage of cytosine equals the percentage of guanine. This proved invaluable to the eventual discovery of which aspect of DNA?

• Location

• Volume

• Structure

• Solubility