DNA Structure and Composition

Where is DNA located in a cell?

• In the cytoplasm

• In the nucleus

• In the ribosomes

• In the cell wall

In the DNA double helix, what forms the “sides” of the twisted ladder?

• The nitrogenous bases

• The proteins

• The sugar and phosphate groups

• Amino acids

What forms the “steps” or rungs of the DNA ladder?

• Ribosomes

• Base pairs

• Covalent bonds

• Lipids

What gives DNA its twisted, helical shape?

• The linear arrangement of nucleotides

• The sugar molecules only

• The cell’s external pressure

• The twisting of its two strands

What is the main function of DNA?

• To produce energy for the cell

• To hold the instructions for making proteins and passing traits

• To help the cell move

• To digest food

Which sugar is found in DNA?

• Glucose

• Ribose

• Fructose

• Deoxyribose

How many strands does RNA usually have?

• Two strands

• Three strands

• One strand

• Four strands

Which base does RNA use instead of thymine?

• Adenine

• Cytosine

• Guanine

• Uracil

How is the genetic code read in the cell?

• Two bases at a time

• Three bases at a time (each set is called a codon)

• One base at a time

• Four bases at a time

What does each codon specify?

• A nucleotide

• A single amino acid

• A protein

• A sugar molecule