Activity #2 Question Set (The Structure & Function of GeneChip Microarrays)
Student Handout Response Sheet: Used with Lab 5
Activity #2 Question Set
(The Structure & Function of GeneChip Microarrays)
Directions: The following questions go with Activity #2 reading on the structure and function of GeneChip microarrays. Answer each question as thoroughly and detailed as possible.
Part I – Intro, and Gene Expression Microarrays
(1) What is gene expression? What can affect gene expression?
• When a gene is used to build an mRNA copy (transcription) which is then used to guide the synthesis of a protein (translation), the gene has been
“expressed”. Thus the term gene expression refers to anytime a gene is
“turned on”, leading to the synthesis of the protein it codes for.
• Gene expression can be affected by mutations or environmental factors.
Thus the expression of genes is not always consistent within an organism.
(2) Are all genes expressed in all cells? Explain why or why not. How do scientists study gene expression?
No, not all genes are expressed in every single cell of an organism. Genes that code for vital functions needed by all cells (like getting energy from food) maybe expressed in all cells, while those needed by only specific cells will be found expressed in those cells only (such as pigments that protect skin cells).
• By measuring the amount of RNA copies a gene produces, scientists can study that gene’s level of expression. A highly expressed gene will produce a lot more RNA than a gene that is expressed in small amounts.
A gene expression microarray can be used to detect both the presence and amount of RNA present in a cell.
(3) What would researchers have to do in order to make a hypothesis about gene expression in the past, before the use of the microarrays? What can they know do with the use of microarrays?
Scientists would have to refer to previous research on similar diseases or topics and extrapolate from that information. They would then have to form a hypothesis
Activity #2 Question Set
(The Structure & Function of GeneChip Microarrays)
Directions: The following questions go with Activity #2 reading on the structure and function of GeneChip microarrays. Answer each question as thoroughly and detailed as possible.
Part I – Intro, and Gene Expression Microarrays
(1) What is gene expression? What can affect gene expression?
• When a gene is used to build an mRNA copy (transcription) which is then used to guide the synthesis of a protein (translation), the gene has been
“expressed”. Thus the term gene expression refers to anytime a gene is
“turned on”, leading to the synthesis of the protein it codes for.
• Gene expression can be affected by mutations or environmental factors.
Thus the expression of genes is not always consistent within an organism.
(2) Are all genes expressed in all cells? Explain why or why not. How do scientists study gene expression?
No, not all genes are expressed in every single cell of an organism. Genes that code for vital functions needed by all cells (like getting energy from food) maybe expressed in all cells, while those needed by only specific cells will be found expressed in those cells only (such as pigments that protect skin cells).
• By measuring the amount of RNA copies a gene produces, scientists can study that gene’s level of expression. A highly expressed gene will produce a lot more RNA than a gene that is expressed in small amounts.
A gene expression microarray can be used to detect both the presence and amount of RNA present in a cell.
(3) What would researchers have to do in order to make a hypothesis about gene expression in the past, before the use of the microarrays? What can they know do with the use of microarrays?
Scientists would have to refer to previous research on similar diseases or topics and extrapolate from that information. They would then have to form a hypothesis