Nucleic Acids Quiz

What are the building blocks of nucleic acids?

• Amino acids

• Nucleotides

• Fatty acids

• Monosaccharides

Answer explanation

Nucleic acids, such as DNA and RNA, are composed of nucleotides. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base, making them the fundamental building blocks of these essential biomolecules.

How are nucleotides in DNA joined together?

• Ionic bonds

• Hydrogen bonds

• Covalent bonds

• Metallic bonds

Answer explanation

Nucleotides in DNA are joined together by covalent bonds, specifically phosphodiester bonds, which link the sugar of one nucleotide to the phosphate group of the next. This forms the backbone of the DNA strand.

What are the three components of a DNA nucleotide?

• A 5 carbon sugar, a phosphate group, and a nitrogenous base

• A 6 carbon sugar, a phosphate group, and a nitrogenous base

• A 5 carbon sugar, a sulfate group, and a nitrogenous base

• A 6 carbon sugar, a sulfate group, and a nitrogenous base

Answer explanation

A DNA nucleotide consists of three components: a 5 carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). This makes the first answer choice correct.

Tags

NGSS.HS-LS1-1

How do nucleotides join together to form strands of DNA?

• Through covalent bonds

• Through ionic bonds

• Through hydrogen bonds

• Through metallic bonds

Answer explanation

Nucleotides join together to form strands of DNA through covalent bonds, specifically between the phosphate group of one nucleotide and the sugar of another, creating a strong backbone for the DNA structure.

Which of the following is not a nitrogenous base found in DNA?

• Adenine

• Guanine

• Uracil

• Thymine

Answer explanation

Uracil is not a nitrogenous base found in DNA; it is found in RNA. The nitrogenous bases in DNA are adenine, guanine, and thymine.

Tags

NGSS.HS-LS1-1

What are the four kinds of nitrogenous bases used in DNA?

• Adenine, Guanine, Cytosine, Thymine

• Adenine, Guanine, Cytosine, Uracil

• Adenine, Thymine, Uracil, Cytosine

• Guanine, Thymine, Uracil, Cytosine

Answer explanation

The four nitrogenous bases in DNA are Adenine, Guanine, Cytosine, and Thymine. Uracil is found in RNA, not DNA, making the first option the correct answer.

According to Chargaff's Rule, which base pairs with Adenine (A) in DNA?

• Cytosine (C)

• Guanine (G)

• Thymine (T)

• Uracil (U)

Answer explanation

According to Chargaff's Rule, Adenine (A) pairs with Thymine (T) in DNA. This base pairing is crucial for the structure and function of DNA, ensuring proper replication and stability.

What mnemonic can help remember the pairing of Adenine and Thymine in DNA?

• Apples belong in Trees

• Cars belong in Garages

• Birds fly in the Sky

• Fish swim in Water

Answer explanation

The mnemonic "Apples belong in Trees" helps remember that Adenine (A) pairs with Thymine (T) in DNA, as both start with the letter 'A' and 'T', similar to how apples grow on trees.

Which base pairs with Cytosine (C) in DNA according to Chargaff's Rule?

• Adenine (A)

• Thymine (T)

• Guanine (G)

• Uracil (U)

Answer explanation

According to Chargaff's Rule, Cytosine (C) pairs with Guanine (G) in DNA. This complementary base pairing is essential for the structure and function of DNA.

What did Franklin's X-Rays reveal about the structure of DNA?

• DNA strands are parallel to each other

• DNA strands are twisted like coils or springs

• DNA strands are flat and linear

• DNA strands are circular

Answer explanation

Franklin's X-Rays showed that DNA strands are twisted like coils or springs, indicating a helical structure. This was crucial in understanding the three-dimensional shape of DNA.