DNA RNA Base Pairs

The drawing shows the structure of what molecule?

• A DNA molecule
• A lipid molecule
• A carbohydrate molecule
• A protein molecule

The table shows the results of measuring the percentages of the four bases in the DNA of several different organisms. Some of the values are missing from the table. Based on Chargaff’s rule, the percentages of guanine bases in chicken DNA should be approximately what?

• 28.8%
• 19.9%
• 21.5%
• 13.4%

Based on Chargaff’s rule, the percentage of cytosine in the DNA of the bacterium, S. lutea in the table, should be approximately what?

• 26.6%.
• 73.2%.
• 36.6%.
• 29.4%.

Which of the following statements correctly describes Chargaff’s contribution to the study of DNA?

• Chargaff hypothesized that DNA was a double helix.
• Chargaff’s experiments conclusively proved that DNA was made of nucleotides.
• Chargaff showed that adenine and thymine were found in equal percentages in DNA.
• Chargaff’s work proved that DNA could be made using radioactive nucleotides.

In the drawing, what nucleotide is going to be added at point 1, opposite from thymine?

• adenine
• thymine
• cytosine
• guanine

In the drawing, what chemical is adding base pairs to the strand?

• DNA polymerase
• nucleosomes
• histonase
• chromatinase

All of the following statements are true of a DNA molecule except that it-

• is made up of lipids.
• contains nucleotides.
• stores genetic information.
• duplicates itself.

The macromolecules that make up nucleic acids contain which of the following elements?

• Hydrogen and nitrogen only
• Nitrogen and oxygen only
• Hydrogen, nitrogen, and phosphorus
• Hydrogen, nitrogen, oxygen, and phosphorus

Which of the following best defines a gene?

• A diploid cell containing two sets of chromosomes
• A unit made up of chromosomes that control for a specific trait
• A segment of DNA that codes for a particular protein
• All the other answers are correct.

What is a nucleotide? 

• A monomer made of a 5-carbon sugar, a phosphate group, and a nitrogenous base
• A monomer made of a adenosine triphosphate, a phosphate, and a sugar
• A polymer made of DNA and RNA
• No other choice is correct.