DNA History & Structure

Multiple Choice

According to Chargaff's rules, the amount of adenine (A) in a DNA molecule is always equal to the amount of which base?

• Cytosine (C)

• Guanine (G)

• Thymine (T)

• Uracil (U)

Multiple Choice

If a DNA molecule has 40% guanine, what percentage of the molecule is adenine?

• 10%

• 20%

• 30%

• 40%

Multiple Choice

In a DNA molecule, if 20% of the bases are thymine, what percentage of the bases are guanine?

• 20%

• 30%

• 40%

• 60%

Multiple Choice

Which scientist's rule established the chemical basis for complementary base pairing in DNA?

• Rosalind Franklin

• Erwin Chargaff

• James Watson

• Francis Crick

Multiple Choice

Which of the following statements about the discovery of DNA's structure is correct?

• Watson and Crick discovered DNA's structure using only their own ideas.

• Franklin's X-ray crystallography techniques were not important to the discovery.

• Chargaff's rules for base pairing were ignored in the discovery.

• Watson and Crick built on the work of other scientists to discover DNA's double helix shape.

Hotspot

Which arrow is pointing to the hydrogen bonds that are connecting nitrogen bases?

Hotspot

Select ALL the Phosphate Groups

Multiple Select

Which of the following are parts of a nucleotide?

• Phosphate

• Sugar

• Nitrogenous base

• Fatty acid

Labelling

Label the Nucleotide

Drag labels to their correct position on the image

phosphate

Nitrogen base

Deoxyribose Sugar

Match

Match the following DNA base pairs.

• Adenine pairs with

• Thymine pairs with

• Cytosine pairs with

• Guanine pairs with

Thymine

Adenine

Guanine

Cytosine

• Thymine

• Adenine

• Guanine

• Cytosine

Multiple Choice

Which base pair forms a triple bond in DNA?

• Adenine-Thymine

• Cytosine-Guanine

• Thymine-Guanine

• Adenine-Cytosine

Multiple Choice

Which part of a DNA strand is referred to as the 'head' and which as the 'tail', and what determines these ends?

• 5' end is the head, 3' end is the tail, determined by specific carbon atoms in the sugar molecule

• 3' end is the head, 5' end is the tail, determined by nitrogenous bases

• 5' end is the head, 3' end is the tail, determined by phosphate groups

• 3' end is the head, 5' end is the tail, determined by hydrogen bonds