Chargaff's Rules and DNA Structure

What are the four nitrogenous bases that make up the DNA molecule?

• Adenine, Cytosine, Guanine, Uracil

• Adenine, Cytosine, Guanine, Thymine

• Alanine, Cysteine, Glycine, Tyrosine

• Asparagine, Cysteine, Glutamine, Threonine

Which scientist discovered that in any species' DNA, the proportions of adenine and thymine are equal, as are the proportions of cytosine and guanine?

• James Watson

• Francis Crick

• Erwin Chargaff

• Rosalind Franklin

What was the significance of Chargaff's findings regarding the proportions of nitrogenous bases in DNA?

• It proved that DNA is a protein.

• It helped in understanding the double helix structure of DNA.

• It showed that DNA varies greatly between different cells of the same organism.

• It indicated that DNA is composed of RNA.

Which statement accurately describes Chargaff's proportions across different life forms?

• Chargaff's proportions are unique to each individual organism.

• Chargaff's proportions are universal, but the balance of AT and CG pairs varies between species.

• Chargaff's proportions only apply to bacterial DNA.

• Chargaff's proportions are not observed in all life forms.