Q: Which of the following best describes the Central Dogma of Molecular Biology?

$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$$

Question 1

Which experiment provided the first direct evidence that DNA, and not protein, is the genetic material in cells?

Accepted Answer

Hershey-Chase bacteriophage experiment (1952)

Question 2

Which of the following best describes the structural difference between deoxyribose and ribose sugars?

Accepted Answer

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

Question 3

A DNA molecule is composed of two strands that run in opposite directions. What is the term used to describe this arrangement?

Accepted Answer

Antiparallel

Question 4

Which of the following base pairings is correct according to the rules of DNA structure?

Accepted Answer

Adenine pairs with Thymine

Question 5

Which of the following statements about restriction enzymes is TRUE?

Accepted Answer

They recognize and cleave specific DNA sequences called recognition sites.

Question 6

During gel electrophoresis, why do shorter DNA fragments move faster through the gel than longer fragments?

Accepted Answer

Shorter fragments encounter less resistance as they move through the gel matrix.

Question 7

Which of the following best explains why DNA is able to store genetic information?

Accepted Answer

The sequence of nitrogenous bases encodes instructions for building proteins.

Question 8

A scientist wants to amplify a specific DNA sequence from a small blood sample for forensic analysis. Which technique should they use?

Accepted Answer

Polymerase Chain Reaction (PCR)

Question 9

Which of the following is a key difference between DNA and RNA?

Accepted Answer

RNA is usually single-stranded, while DNA is double-stranded.

Question 10

Which of the following best describes the Central Dogma of Molecular Biology?

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 11

A mutation occurs in the gene encoding a restriction enzyme, causing it to lose its ability to recognize its specific recognition site. What is the most likely consequence?

Accepted Answer

The enzyme will not cut DNA at all.

Question 12

Which of the following is TRUE about complementary DNA (cDNA)?

Accepted Answer

cDNA is synthesized from mRNA using reverse transcriptase and lacks introns.

Question 13

If a DNA sample contains 30% adenine, what percentage of guanine would you expect to find?

Accepted Answer

20%

Question 14

Which of the following best explains why DNA denaturation is important in molecular genetics techniques such as PCR?

Accepted Answer

Denaturation separates the two DNA strands, allowing primers to anneal and DNA polymerase to synthesize new strands.

Question 15

Which of the following statements about nucleosomes is correct?

Accepted Answer

Nucleosomes are formed by DNA wrapping around histone proteins.

Question 16

A forensic scientist is analyzing a DNA sample using gel electrophoresis. The DNA fragments are loaded at the negative end of the gel. Which direction will the DNA fragments move, and why?

Accepted Answer

Toward the positive end, because DNA is negatively charged.

Question 17

Which of the following is a function of DNA that allows for evolution and adaptation in populations?

Accepted Answer

DNA allows for variation through mutation.

Question 18

Which of the following best describes the role of dNTPs in DNA replication?

Accepted Answer

dNTPs are the monomeric building blocks that are added to the growing DNA strand.

Question 19

A researcher is studying a gene that is only expressed in liver cells. Which molecular process is most directly responsible for this cell-specific gene expression?

Accepted Answer

Gene regulation at the transcriptional level

Question 20

Which of the following is a real-world application of DNA analysis in medicine?

Accepted Answer

Diagnosing genetic diseases by detecting mutations in patient DNA

Introduction to Molecular Genetics: DNA Structure and Analysis

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