DNA

Front

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

Back

TAC ACT GTC

Answer explanation

The complementary DNA bases pair according to base pairing rules: A with T and G with C. Therefore, ATG TGA CAG pairs with TAC ACT GTC, making it the correct choice.

Front

Which of the following best describes a DNA molecule?

Back

double helix

Answer explanation

A DNA molecule is best described as a double helix, which refers to its twisted ladder structure. The other options are incorrect: DNA contains deoxyribose, not ribose, is made of nucleotides, not amino acids, and contains thymine instead of uracil.

Front

Monomers repeatedly joined to form a strand of DNA.

Back

nucleotides

Answer explanation

Nucleotides are the monomers that make up DNA. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base, and they are linked together to form the DNA strand.

Front

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

Back

thymine

Answer explanation

In double-stranded DNA, adenine (A) pairs with thymine (T) through hydrogen bonds. Therefore, the amount of adenine is always equal to the amount of thymine, making thymine the correct answer.

Front

What determines the code, or information, of a DNA molecule?

Back

the order (sequence) of the nitrogen bases

Answer explanation

The code of a DNA molecule is determined by the order (sequence) of the nitrogen bases. This sequence encodes the genetic information, while the shape, color, and frequency of the bases do not define the genetic code.

Front

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

Back

deoxyribose sugar and phosphate

Answer explanation

The sides of the DNA ladder are formed by deoxyribose sugar and phosphate. These components create the sugar-phosphate backbone, which supports the nitrogenous bases that make up the rungs of the ladder.

Front

The two strands of nitrogenous bases in DNA are joined by which type of bond?

Back

hydrogen bonds

Answer explanation

The two strands of DNA are held together by hydrogen bonds between complementary nitrogenous bases. These weak bonds allow the strands to separate during processes like replication and transcription.

Front

A process in which DNA has the unique ability to make an exact copy of itself.

Back

Replication

Answer explanation

Replication is the process by which DNA makes an exact copy of itself, ensuring genetic information is passed on during cell division. Translation and transcription are related to protein synthesis, not DNA copying.

Front

The drawing shows the structure of what molecule?

Back

A DNA molecule

Answer explanation

The structure depicted is characteristic of a DNA molecule, which consists of two strands forming a double helix, with nucleotide bases pairing. This distinguishes it from lipids, carbohydrates, and proteins.

Front

What are the three components of a nucleotide?

Back

sugar, phosphate, nitrogen base

Answer explanation

A nucleotide consists of three components: a sugar molecule, a phosphate group, and a nitrogen base. The correct answer is 'sugar, phosphate, nitrogen base', as the other options include incorrect components.