Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 2

During transcription, which strand of DNA serves as the template for RNA synthesis?

Accepted Answer

The DNA template strand (3' to 5')

Question 3

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

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

Question 4

Which codon serves as the universal start codon for translation in most organisms?

Accepted Answer

$$\mathrm{AUG}$$

Question 5

A mutation changes a codon from $$\mathrm{UUA} to$$ $$\mathrm{UAA} in an $$mRNA sequence. What is the likely effect on translation?

Accepted Answer

Translation will terminate prematurely because $$\mathrm{UAA} is a $$stop codon.

Question 6

Which of the following statements about the genetic code is correct?

Accepted Answer

The code is non-overlapping, meaning each nucleotide is part of only one codon.

Question 7

Which enzyme is responsible for attaching an amino acid to its corresponding tRNA?

Accepted Answer

Aminoacyl-tRNA synthetase

Question 8

In eukaryotic cells, which process occurs in the nucleus and involves the removal of introns from pre-mRNA?

Accepted Answer

RNA splicing

Question 9

Which of the following is a function of the 5' cap added to eukaryotic mRNA?

Accepted Answer

It protects mRNA from degradation and assists in ribosome binding during translation.

Question 10

A tRNA has the anticodon $$\mathrm{UAC}. $$Which mRNA codon will it recognize, and which amino acid will it carry?

Accepted Answer

$$\mathrm{AUG}$$; methionine

Question 11

Which of the following is true regarding ribosomes in prokaryotes and eukaryotes?

Accepted Answer

Prokaryotic ribosomes are 70S, while eukaryotic ribosomes are 80S.

Question 12

Which of the following is an exception to the universal genetic code?

Accepted Answer

$$\mathrm{UGA}$$ codes for tryptophan in human mitochondria.

Question 13

What is the role of the TATA box in transcription?

Accepted Answer

It serves as a promoter region where transcription factors bind to initiate transcription.

Question 14

Which of the following best explains why the genetic code is described as 'degenerate'?

Accepted Answer

More than one codon can specify the same amino acid.

Question 15

A mutation in the gene encoding a tRNA synthetase results in the enzyme attaching the wrong amino acid to a tRNA. What is the most likely consequence?

Accepted Answer

The wrong amino acid will be incorporated into the protein at the corresponding codon.

Question 16

Which of the following steps occurs first during the initiation of translation in prokaryotes?

Accepted Answer

The small ribosomal subunit binds to the mRNA.

Question 17

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

Accepted Answer

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

Question 18

Which of the following best describes the function of the anticodon loop of tRNA?

Accepted Answer

It base-pairs with the complementary codon on mRNA during translation.

Question 19

Which of the following is a direct result of alternative splicing of pre-mRNA?

Accepted Answer

A single gene can produce multiple protein isoforms.

The Genetic Code and Transcription: From DNA to Protein

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