Unit 3

Which of the following best describes a DNA molecule?

• double helix
• contains ribose
• made of amino acids
• contains Uracil

Which sequence of DNA bases would pair with this partial strand
ATG TGA CAG

• ATG TGA CAG
• TAC ACT GTC
• GTA AGT GAC
• CAT TCA CTG

Which of the following units are repeatedly joined together to form a strand of DNA?

• amino acids
• nucleotides
• fatty acids
• polysaccharides

Why is DNA important?

• it is very small and very complicated
• it's in everything
• it serves as the blueprint for traits of all living things
• because we eat it every day for energy

In what phase of the cell cycle does DNA replication take place?

• G1
• S
• G2
• M

Nitrogenous bases are joined by which type of bond?

• polar bonds
• ionic bonds
• covalent bonds
• hydrogen bonds

In a molecule of double-stranded DNA, the amount of Adenine present is always equal to the amount of

• cytosine
• guanine
• thymine
• uracil

What sugar is in DNA?

• deoxyribose
• ribose
• oxyribose
• deoxyose

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

• deoxyribose sugar and adenine
• deoxyribose sugar and a hydrogen bond
• deoxyribose sugar and the nucleus
• deoxyribose sugar and phosphate

What are the three components of a nucleotide?

• sugar, hydrogen, nitrogen base
• sugar, oxygen, nitrogen base
• sugar, phosphate, nitrogen base
• sugar, phosphate, protein