Question 1

Which of the following best describes the primary function of nucleic acids in living organisms?

Accepted Answer

They store, transmit, and help express hereditary information.

Question 2

What is the correct sequence of events in the central dogma of molecular biology?

Accepted Answer

DNA → RNA → Protein

Question 3

Which of the following statements about nucleotides is TRUE?

Accepted Answer

A nucleotide consists of a nitrogenous base, a pentose sugar, and one or more phosphate groups.

Question 4

Which bond is responsible for linking nucleotides together in a polynucleotide chain?

Accepted Answer

Phosphodiester bond

Question 5

Which of the following nitrogenous bases is found in RNA but not in DNA?

Accepted Answer

Uracil

Question 6

What is the main structural difference between deoxyribose and ribose sugars?

Accepted Answer

Deoxyribose has a hydrogen at the 2' position, while ribose has a hydroxyl group at the 2' position.

Question 7

Which of the following correctly matches the nitrogenous base with its classification?

Accepted Answer

Adenine – Purine

Question 8

In a DNA double helix, which base pairs with guanine, and how many hydrogen bonds are formed between them?

Accepted Answer

Cytosine; 3 hydrogen bonds

Question 9

Which of the following best explains why DNA strands are described as antiparallel?

Accepted Answer

One strand runs 5' to 3', while the other runs 3' to 5'.

Question 10

Which of the following statements about ATP (adenosine triphosphate) is correct?

Accepted Answer

ATP is a nucleotide composed of adenine, ribose, and three phosphate groups.

Question 11

Which type of bond in ATP contains the most energy and is most often broken to release energy for cellular work?

Accepted Answer

Phosphoanhydride bond

Question 12

A scientist is analyzing a nucleic acid sample and finds it contains uracil, ribose, and is single-stranded. What is the most likely identity of this molecule?

Accepted Answer

RNA

Question 13

Which of the following is a correct description of a nucleoside?

Accepted Answer

A molecule consisting of a nitrogenous base and a sugar, without a phosphate group.

Question 14

Which of the following best explains the importance of the sequence of nitrogenous bases in DNA?

Accepted Answer

It encodes the genetic information necessary for protein synthesis.

Question 15

During the process of transcription, what is synthesized from a DNA template?

Accepted Answer

Messenger RNA (mRNA)

Question 16

Which of the following is a property of the sugar-phosphate backbone of nucleic acids?

Accepted Answer

It is hydrophilic due to the presence of polar groups.

Question 17

A mutation causes a cytosine in DNA to be replaced by thymine. Which of the following base pairing changes would occur as a result?

Accepted Answer

A G-C pair would be replaced by an A-T pair.

Question 18

Which of the following best describes the directionality of nucleic acid synthesis?

Accepted Answer

Nucleic acids are synthesized from the 5' end to the 3' end.

Question 19

Which of the following scenarios best illustrates the application of complementary base pairing in a real-world context?

Accepted Answer

A forensic scientist uses DNA base pairing to match a suspect's DNA to evidence from a crime scene.

Bio 100 LEC Chapter 5 Part 3 UPDATED

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