Why Do Animal Viruses Have Envelopes and Phages Rarely Do

question 93

Multiple Choice

Why do animal viruses have envelopes and phages rarely do?

• A)Since bacteria don't have cell membranes,the bacterial viruses (phages)don't pick them up when they leave the target cells.
• B)Phages acquire an outer surrounding that is a part of the cell wall of the bacterium they were created in,rather than an outer surrounding of plasma membrane.
• C)Animal viruses will often utilize the envelope in order to fuse with the plasma membrane of a new target cell,gaining entry into the cytoplasm.
• D)Animal viruses build the envelope inside of the target cell as they are being replicated,but before the cell breaks open and releases them into the extracellular environment.The envelope is a remnant of this building process.

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Definitions:

Sex Pilus

A thin, tube-like structure used by some bacteria to transfer genetic material to another bacterium during conjugation, a form of sexual reproduction.

Gap Junctions

Specialized structures in animal cell membranes that allow for direct communication between cells through the passage of ions and molecules.

Tight Junction

Cell junction that fastens together the plasma membrane of adjacent epithelial cells; collectively prevent fluids from leaking between the cells. Composed of adhesion proteins.

Plasmodesma

Cell junction that forms an open channel between the cytoplasm of adjacent plant cells.