Question 1

Which statement best describes the Central Dogma of molecular biology?

Accepted Answer

Genetic information flows from DNA to RNA to protein.

Question 2

A mutation in the gene encoding an enzyme required for pigment synthesis in donkeys leads to a change in coat color. Which process directly links this genetic change to the observed phenotype?

Accepted Answer

Translation of mRNA to protein

Question 3

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

Accepted Answer

The template strand

Question 4

Which of the following modifications occur to eukaryotic pre-mRNA before it becomes mature mRNA?

Accepted Answer

Addition of a 5' guanine cap and a poly-A tail

Question 5

A base substitution mutation changes a codon from $$\mathrm{GAA} to$$ $$\mathrm{GAG}. $$What is the likely effect on the protein?

Accepted Answer

A silent mutation with no change in the amino acid sequence

Question 6

Which property of the genetic code allows a gene from a jellyfish to be expressed in a tobacco plant?

Accepted Answer

The code is universal

Question 7

What is the role of tRNA during translation?

Accepted Answer

It shuttles amino acids to the ribosome and matches them to the mRNA codon via its anticodon.

Question 8

A mutation causes a frameshift in the coding region of a gene. What is the most likely consequence?

Accepted Answer

The reading frame is altered, changing all downstream amino acids.

Question 9

Which enzyme is responsible for synthesizing RNA during transcription?

Accepted Answer

RNA polymerase

Question 10

Alternative splicing of pre-mRNA allows eukaryotic cells to:

Accepted Answer

Produce multiple proteins from a single gene

Question 11

Which of the following is NOT a possible final product of an expressed gene?

Accepted Answer

DNA polymerase

Question 12

What is the function of the signal peptide in protein synthesis?

Accepted Answer

It directs the ribosome to the endoplasmic reticulum for secretion or membrane insertion.

Question 13

Which of the following best explains why all cells in a multicellular organism contain the same DNA but have different functions?

Accepted Answer

Cells express different subsets of genes.

Question 14

Which process removes introns from pre-mRNA in eukaryotes?

Accepted Answer

Spliceosome

Question 15

A ribozyme is best described as:

Accepted Answer

A catalytic RNA molecule that can splice RNA

Question 16

Which of the following mutations is most likely to result in a nonfunctional protein?

Accepted Answer

Frameshift mutation

Question 17

If the template DNA strand reads $$3'-GCCACGTCTCA-5'$$, what is the sequence of the mRNA produced?

Accepted Answer

$$5'-CGGUGCAGAGU-3'$$

Question 18

Which stage of translation always begins at the codon AUG?

Accepted Answer

Initiation

Question 19

What is the main consequence of a nonsense mutation in a coding region?

Accepted Answer

A premature stop codon, truncating the protein

Question 20

Which of the following best describes the relationship between genotype and phenotype?

Accepted Answer

Genotype determines phenotype by dictating the synthesis of proteins.

Gene Expression: From Gene to Protein (Chapter 17 Study Notes)

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