Unit 12: Nucleic Acids Retake

Which molecule is found in both DNA and RNA?

• Ribose

• Uracil

• Phosphate

• Amino Acid

The following diagram shows a short stretch of DNA. What bases are indicated by labels Y and Z?

• Y is thymine, Z is adenine

• Y is thymine, Z is guanine

• Y is uracil, Z is guanine

• Y is uracil, z is adenine

Which molecules form the nucleotide marked in the diagram? (Choose the best possible answer)

• phosphate, deoxyribose and nitrogenous base

• phosphorus, ribose and nitrogenous base

• phosphorus, deoxyribose and guanine

• phosphate, ribose and guanine

The base ratios in the DNA and RNA for an onion (Allium cepa) are given below.

• DNA is only found in the nucleus but RNA is found throughout the cell.

• DNA is made entirely of double helix but RNA is not.

• In DNA, bases A and T are complementary but in RNA, bases A and C are complementary.

• RNA comes in three forms but DNA only comes in one form.

The percentage of thymine in the DNA of an organism is approximately 30%. What is the percentage of guanine?

• 70%

• 30%

• 40%

• 20%

In the model of the DNA molecule shown here, which arrows point to covalent bonds?

• I, II and III only

• II, III and IV only

• I, III and IV only

• I, II and IV only

The diagram shows one DNA nucleotide and part of a second nucleotide.

State the names of structures I and II. (both must be correct to be awarded the point)

The diagram shows two nucleotides linked together to form a dinucleotide.

Identify the chemical group labeled I.

The diagram below shows two nucleotides linked together to form a dinucleotide.

State the type of bond labeled II.

State the type of bonds that connect base pair in a DNA molecule.