PBS DNA Structure Part 2

PBS DNA Structure

Multiple Choice

Which 2 molecules forms the sides (backbone) of the DNA ladder?

• deoxyribose and adenine

• deoxyribose and a hydrogen bond

• sugar and the nucleus

• deoxyribose (sugar) and phosphate

Nitrogenous Bases

Purines: 2 rings--A and G

Pyrimidines: 1 ring-- Cyto and Thy

Multiple Choice

What is the main difference between purines and pyrimidines?

• purines have 1 ring and pyrimidines have 2 rings

• purines have 2 rings and pyrimidines have 1 ring

• purines have more hydrogen bonds than pyrimidines

• purines have fewer hydrogen bonds than pyrimidines

Multiple Choice

Please identify the nitrogenous base.

• Adenine

• Guanine

• Thymine

• Cytosine

Multiple Choice

Please identify the nitrogenous base.

• Adenine

• Guanine

• Thymine

• Cytosine

Adenine or Guanine?

Cytosine or Thymine?

Multiple Choice

Which images represents Thymine?

Multiple Choice

Which images represents Guanine?

Multiple Choice

Which images represents Cytosine?

Multiple Choice

Which images represents adenine?

Multiple Choice

What group do these bases belong to?

• Purines

• Pyrimidines

Poll

What I know about DNA....

• Shape of DNA

• Parts of Nucleotide

• Base Pairs

• Shape of Purines and Pyramidines