Biology, Eighth Edition (Raven)

Chapter 15: Genes and How They Work

Simple Gene Expression

What is meant by gene expression? In a multicellular organism, usually every cell contains the complete genome. All genes are present in every nucleus. However, in any given cell, only some of the genes are actually producing mRNA. Many of the genes are inactive and never do anything. Other genes only produce mRNA at certain points in the life of a cell or in response to certain conditions. The production of mRNA is known as gene expression. Genes that do not produce mRNA and do not contribute to the phenotype are not being expressed.

View the animation below, then complete the quiz to test your knowledge of the concept.



1.

Which of the following best describes transcription?
A)DNA -> DNA
B)DNA -> RNA
C)DNA -> Protein
D)RNA -> DNA
E)RNA -> Protein
2.

Which of the following best describes translation?
A)DNA -> DNA
B)DNA -> RNA
C)DNA -> Protein
D)RNA -> DNA
E)RNA -> Protein
3.

Nucleotides are the building blocks of
A)DNA only.
B)RNA only.
C)both DNA and RNA.
D)neither DNA nor RNA.
E)cells.
4.

A structural gene encodes the information for a specific protein.
A)True
B)False
5.

The amino acid sequence of a protein determines its shape and specific function.
A)True
B)False
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