Q: Which of the following best describes the Central Dogma of molecular biology?

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

Question 1

Which scientist's experiment with Streptococcus pneumoniae first demonstrated the 'transforming principle' that suggested DNA could transfer genetic information between cells?

Accepted Answer

Frederick Griffith

Question 2

What was the key finding from the Hershey-Chase experiment that confirmed DNA as the genetic material?

Accepted Answer

Radioactive phosphorus was found in the bacterial pellet.

Question 3

Which of the following best describes the role of Rosalind Franklin in the discovery of DNA structure?

Accepted Answer

She produced X-ray diffraction images that revealed the helical structure of DNA.

Question 4

According to Chargaff's rules, if a DNA sample contains 30% adenine, what percentage of guanine would you expect?

Accepted Answer

$$20\%$$

Question 5

Which enzyme is responsible for adding nucleotides to a growing DNA strand during replication?

Accepted Answer

DNA polymerase

Question 6

During transcription, which molecule is synthesized from a DNA template?

Accepted Answer

mRNA

Question 7

Which of the following best describes the Central Dogma of molecular biology?

Accepted Answer

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

Question 8

A mutation changes a codon from UAU (tyrosine) to UAA. What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 9

Which process occurs at the ribosome and involves decoding mRNA to build a polypeptide chain?

Accepted Answer

Translation

Question 10

What is the function of tRNA during translation?

Accepted Answer

It carries amino acids to the ribosome.

Question 11

Which of the following is a difference between prokaryotic and eukaryotic gene expression?

Accepted Answer

Prokaryotes can begin translation before transcription is complete.

Question 12

A patient has a genetic disorder caused by a single nucleotide insertion in a coding region. What is the most likely effect on the protein product?

Accepted Answer

The reading frame is shifted, altering all downstream amino acids.

Question 13

Which of the following best explains why the COVID-19 mRNA vaccine is effective?

Accepted Answer

It provides mRNA that is translated into viral protein, stimulating an immune response.

Question 14

Which of the following is NOT a step in eukaryotic mRNA processing?

Accepted Answer

Direct translation without modification

Question 15

If a DNA template strand has the sequence $$3'	ext{-TACGGTACG-}5'$$, what is the corresponding mRNA sequence?

Accepted Answer

$$5'	ext{-AUGCCAUGC-}3'$$

Question 16

Which of the following best describes a frameshift mutation?

Accepted Answer

A mutation that shifts the reading frame by inserting or deleting nucleotides

Question 17

Which enzyme is responsible for synthesizing RNA during transcription?

Accepted Answer

RNA polymerase

Question 18

Which of the following is a real-life example of a point mutation causing a genetic disorder?

Accepted Answer

Sickle cell anemia caused by a single nucleotide substitution

Question 19

Which process ensures that only the exons of a gene are included in the final mRNA in eukaryotes?

Accepted Answer

Splicing

Question 20

Which of the following best describes the relationship between codons and amino acids?

Accepted Answer

Each codon consists of three nucleotides and codes for one amino acid.

DNA and Protein Synthesis: Key Concepts and Processes

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