DE Gen Bio. I Ch.12

Nucleotides contain all of the following except

• glucose
• fatty acids
• • 
    

    histones.

• cholesterol

Scientists have created genetically modified organisms (GMOs) by isolating and then transferring the jellyfish gene for green fluorescent protein into pigs, bacteria, plants, and mice. The result was bioluminescent organisms! These experiments demonstrate that

• • 
    

    genes have no difficulty crossing the species barrier.

• GMOs cannot exhibit traits from other species.
• Bioluminescence can only occur in marine animals.
• Genetic modification is only possible in plants.

An unknown chemical is analyzed and found to contain the bases thymine and guanine. This chemical is most likely

• Protein
• Carbohydrate
• RNA
• DNA

One of Chargaff's rules states that

• The amount of adenine equals the amount of cytosine, and the amount of thymine equals the amount of guanine.
• The amount of adenine is twice the amount of thymine, and the amount of cytosine is half the amount of guanine.
• The amount of adenine and guanine are equal, while thymine and cytosine vary in proportion.
• • 
    A = T and G = C.

n the Watson and Crick model of DNA, the "steps" of the ladder are composed of

• Proteins (enzymes, structural proteins)
• Phosphate groups (phosphoric acid)
• Sugar molecules (ribose, deoxyribose)
• a purine and a pyrimidine.

Why was the X-ray diffraction photography of Rosalind Franklin and Maurice Wilkins considered critical evidence in the study of DNA?

• The photographs provided evidence for the triple helix model of DNA, contradicting earlier theories.
• Their X-ray diffraction images showed the linear structure of RNA, which misled DNA research.
• Their work focused on protein structures, which had no relevance to DNA's shape.
• The photographs indicated that DNA has a double helix structure.

If one strand of DNA has the base sequence AAG-CAA, the complementary strand has which of the following sequences?

• TTC-GTT

• AAG-CGT
• TTG-CGA
• AAC-GTT

If a DNA sample contains 13% adenine, what percentage of the sample contains cytosine?

Multiple Choice

• 50%
• 45%
• 37%
• 23%

During DNA replication, the enzyme _________blank catalyzes the elongation of new DNA strands.

• DNA polymerase
• DNA ligase
• RNA polymerase
• Helicase

Which of the following statements about DNA replication is NOT correct?

• Replication occurs as each base is paired with another exactly like it.

• DNA replication occurs in a semi-conservative manner.
• DNA replication requires RNA primers to initiate synthesis.
• DNA replication happens in a single direction only.