Help pls..?

Question

1 Which of the following statements does not apply to the Watson and Crick model of DNA?

A) The purines form hydrogen bonds with pyrimidines.

B) The framework of the helix consists of sugar-phosphate units of the nucleotides.

C) The distance between the strands of the helix is uniform.

D) The two strands of the helix are held together by covalent bonds.

E) The two strands of the DNA form a double helix.

2) The strands that make up DNA are antiparallel. This means that

A) the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.

B) the twisting nature of DNA creates nonparallel strands.

C) base pairings create unequal spacing between the two DNA strands.

D) one strand contains only purines and the other contains only pyrimidines.

E) one strand is positively charged and the other is negatively charged.

3) The Y-shaped structure where the DNA double helix is actively unwound during DNA replication is called the

A) replication fork.

B) replication Y.

C) unwinding point.

D) Y junction.

E) elongation junction

Answer 1

1 Which of the following statements does not apply to the Watson and Crick model of DNA?

A) The purines form hydrogen bonds with pyrimidines.

B) The framework of the helix consists of sugar-phosphate units of the nucleotides.

C) The distance between the strands of the helix is uniform.

D) The two strands of the helix are held together by covalent bonds.

E) The two strands of the DNA form a double helix.

ANSWER  D) The two strands of the helix are held together by covalent bonds.

2) The strands that make up DNA are antiparallel. This means that

A) the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.

B) the twisting nature of DNA creates nonparallel strands.

C) base pairings create unequal spacing between the two DNA strands.

D) one strand contains only purines and the other contains only pyrimidines.

E) one strand is positively charged and the other is negatively charged.

ANSWER  A) the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.

3) The Y-shaped structure where the DNA double helix is actively unwound during DNA replication is called the

A) replication fork.

B) replication Y.

C) unwinding point.

D) Y junction.

E) elongation junction

ANSWER  A) replication fork.

Hope this helps!