Suppose That Frog Embryos Are Genetically Manipulated So That the Epidermal

question 106

Multiple Choice

Suppose that frog embryos are genetically manipulated so that the epidermal cells expressed both E-cadherin and N-cadherin on their cell surface. The neuronal tissue and epidermal tissues are collected from the embryos and treated as illustrated in Figure 10.12b. Which of the following would you predict would happen now that N-cadherin is also present on the surface of the epidermal cells?

• A)The genetically modified epidermal cells would adhere to each other and to neuronal cells.
• B)The genetically modified epidermal cells would adhere to neuronal cells and would no longer adhere to epidermal cells.
• C)The genetically modified epidermal cells would adhere to each other, and not to the neuronal cells, because they would still be epidermal cells regardless of the presence of an additional cell adhesion protein on their surface.

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Definitions:

Connexin Proteins

A family of proteins that form gap junctions, allowing direct communication between cells through the exchange of ions and small molecules.

Hemichannel

A type of membrane channel that allows the exchange of ions and small molecules between the intracellular space and the extracellular environment.

Gap Junction

Area of contact between adjacent cells in which connexin proteins in each cell form connecting hemichannels, which, when open, allow ions to pass between the two cells; also called an electrical synapse.

Interneuronal Communication

The transfer of information between neurons within the nervous system, facilitating brain and body functions.