Chromosomes and DNA

What technique did Hershey and Chase use to track proteins and DNA from viruses?

• Radioactive labeling

• X-ray diffraction

• Paper chromatography

• Ultraviolet spectroscopy

Rosalind Franklin used which technology to show the three-dimensional structure of DNA?

• Ultraviolet spectroscopy

• Paper chromatography

• Radioactive labeling

• X-ray diffraction

Chargaff's team performed experiments to compare the relative amounts of nitrogenous bases in DNA samples. Which technique did they use to compare the amounts?

• X-ray diffraction

• Ultraviolet spectroscopy

• Genome sequencing

• Radioactive labeling

What is one discovery made by Chargaff's team about nitrogenous bases in DNA?

• Pyrimidines are larger than purines.

• The amount of adenine is always greater than the amount of cytosine.

• The four nitrogenous bases occur in equal amounts in all species.

• The ratio of purines to pyrimidines is always about 1:1.

What did Chargaff's team find during their experiments with DNA in different species?

• Multicellular species contained mostly pyrimidines.

• Purines always appeared in larger amounts than pyrimidines.

• The amount of purines was always the same as the amount of pyrimidines.

• The ratio of purines to pyrimidines varied widely among species.

How did Chargaff's experiments affect the understanding of DNA's structure?

• They showed that DNA is a polymer made of nucleotides.

• They led to the discovery that purines form base pairs with pyrimidines

• They revealed that each species has unique nitrogenous bases.

• They showed the three-dimensional shape of a DNA molecule.

One DNA strand has a nucleotide with an adenine. What is true of the nucleotide it forms a base pair with?

• It has a thymine.

• It has an adenine.

• It has a cytosine.

• It has a guanine.

Which statement describes base pairing in DNA?

• Adenine pairs with thymine and cytosine but not with guanine.

• Adenine always pairs with cytosine, and guanine always pairs with thymine.

• Adenine always pairs with thymine, and guanine always pairs with cytosine.

• Adenine usually pairs with guanine but can also pair with thymine or cytosine.

Which statement is true of base pairing in DNA?

• One strand has only adenine and guanine, and other strand has only cytosine and thymine.

• One strand has only guanine and cytosine, and the other strand has only adenine and thymine.

• Cytosine in one strand pairs with cytosine in the other strand.

• Guanine in one strand pairs with cytosine in the other strand.

A nucleotide includes a phosphate group, a sugar, and what other component?

• A nucleic acid

• A nitrogenous base

• A protein

• A hydrogen bond