Describe two signals that might cause a cell to go initiate programmed cell death (apoptosis).

Why is a rapidly growing tissue, such as the root tip of a plant, a good model for studying the effects of a drug on cell division?

A human gene called theCFTR gene (for cystic fibrosis transmembrane regulator) encodes aprotein that functions in the transport of chloride ions across the cellmembrane. Most people have two copies of a functional CFTR geneand do not have cystic fibrosis. However, a mutant version of the CFTRgene is found in some people. If a person has two mutant copies ofthe gene, he or she develops the disease known as cystic fibrosis. Arethe following descriptions of this disease related to genetics at themolecular, cellular, organism, or population level?A. People with cystic fibrosis have lung problems due to a buildupof thick mucus in their lungs.B. The mutant CFTR gene encodes a defective chloride transporter.C. A defect in the chloride transporter causes a salt imbalance inlung cells.D. Scientists have wondered why the mutant CFTR gene is relativelycommon. In fact, it is the most common mutant gene that causesa severe disease in persons of Northern European descent. Onepossible explanation why…

Imagine that you created a cell that over-expresses a truncated version of its extrinsic pathway initiator caspase. This protein contains the caspase's DED, but none of the caspase's protease domains. This truncated version is present as an extra copy in addition to the WT copy. In 1-2 sentences, explain what the outcome would be on extrinsic apoptosis (i.e. would it be a positive/negative regulator/have no effect) and why.