Compact DNA Levels of gene control Alteration of structure Relaxed DNA Transcription Pre-MRNA MRNA processing Processed mRNA AAAAA RNA stability Translation 20 Protein (inactive) Postranslational modification Modified protein (active) 16.1 Gene expression can be controlled at multiple levels.

What are three reasons why gene expression might vary across time and across different parts of the body?

Explain the differences between constitutive expressed genes and regulated genes.

Describe three types of post-transcriptional regulation of protein coding genes.

Describe the mechanism of genomic imprinting of the Igf2 gene in mammals.

List two different ways in which trans-acting small RNAs(sRNAs) regulate the expression of target genes.

Two component systems are common in bacteria to regulate the expression of specific genes in response to environmental signals.  Which of the following can be said of two component systems?

List the steps in gene expression that are potentiallysubject to regulation.

You conduct an experiment to study the expression of the S protein through the tissues of your favorite plant (Arabidopsis thaliana). The morning of the experiment you inject in the leaves a messenger RNA that codes for the synthesis of a single protein made of two parts that are attached to each other: the functional S protein and a red fluorescent protein tag (RFP). You perform two cross sections of the same root, one section at the start of the experiment (time = Oh; corresponding to the time of injection) and one section in the afternoon (time = 8h). Through fluorescent microscopy you observe a change in the coloration inside the cells of the root's central tissues (as indicated by the arrows): from no coloration (time = Oh) to red (time = 8h). • The cells of the central tissues in the roots do not have nuclei or ribosomes. How can you explain this change of coloration? Please provide a cellular feature that can lead to this. • What is one advantage of using an RFP-tag in an mRNA?…

An epigenetic study of maternal care in mice was used to study transgenerational epigenetic inheritance. This study found that  increased maternal care during childhood resulted in lower stress levels as adults and decreased maternal care with their own offspring. Increased maternal care during childhood resulted in lower stress levels as adults and increased maternal care with their own offspring. Increased maternal care during childhood resulted in higher stress levels as adults and decreased maternal care with their own offspring. Increased maternal care during childhood resulted in higher stress levels as adults and increased maternal care with their own offspring.