DNA Replication, Structure and History

Erwin Chargaff's rule of base pairing states that:

• adenine pairs with thymine and guanine pairs with cytosine

• adenine pairs with guanine and thymine pairs with cytosine

• purines pair with pyrimidines

• pyrimidines pair only with pyrimidines

Rosanlind Franklin's x-ray diffraction image of her study of DNA was noticed by Watson and Crick and led them to model what they thought the shape and structure of DNA was. What was that shape?

• the double helix

• the single strand

• the sugar and phosphate

• the four nitrogen bases

Thymine, adenine, guanine, cytosine, and uracil are classified as:

• sugars

• codons

• nitrogen bases

• nucleotides

What is the backbone of this DNA molecule made of?

• sugars

• nitrogen bases

• sugar and phosphate

• sugar and nitrogen bases

Semi-conservative replication of DNA refers to the idea that___.

• the two strands of DNA molecules run in opposite directions.

• each new DNA molecule contains 2 new single RNA strands.

• each half of the original DNA molecule is joined with a new complementary DNA strand.

• DNA molecules need to unwind before duplication begins.

Who is responsible for producing this image?

• Francis Crick
• James Watson
• Rosalind Franklin
• Watson and Crick

What was Watson and Crick's main scientific accomplishment?

• Building the first accurate model of DNA
• Isolating strains of pneumonia causing bacteria
• Determining base pairing rules
• Discovering the process of genetic transformation

The work of scientists including Griffin, Avery, Hershey & Chase and Franklin helped us to determine the __ are responsible for carrying genetic material.

• Amino Acids
• Proteins
• Nucleic Acids
• Carbohydrates

If a sample of DNA has 20% ADENINE, how much GUANINE will it have?

• 30%
• 20%
• 80%
• 60%

What makes up the rails, or backbone, of a DNA molecule?

• Alternating sugars and nitrogen bases
• Nitrogen base pairs
• A sugar, a phosphate, and a nitrogen base
• Alternating sugars and phosphates