Gene expression in cells of multicelled eukaryotes changes in response to __________.a. conditions outside the cellb. master gene productsc. operation of operonsd. a and b

Key Concepts: Gene Expression, Multicelled Eukaryotes, Conditions, Master Genes, Operons Explanation: Gene expression refers to the process by which genetic information stored in DNA is used to make a functional gene product, such as a protein. Gene expression can be regulated in several ways and can change in response to various factors such as the conditions outside the cell and the presence of specific regulatory proteins. In multicelled eukaryotes, gene expression is also regulated by master genes that control the expression of many other genes. Operons are found in prokaryotes and consist of a cluster of genes that are transcribed as a single mRNA molecule. Operons do not exist in eukaryotes. Final Answer: d