Using a Macrophage‐like Cell Line, Researchers Infected One Set of Petri

question 19

Multiple Choice

Using a macrophage‐like cell line, researchers infected one set of petri dishes with wild‐type Listeria, and, as anegative control, infected another set with a Listeria mutant that was unable to enter cells. At specific time points, the cells were fixed and prepared for electron microscopy. Two hours after infection, they observed that the wild‐type Listeria in the cytoplasmwere surrounded by ______________.

• A)a cloud of tubulin
• B)a cloud of actin
• C)a cloud of keratin
• D)agrowth cone
• E)comet tails of actin filaments

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Definitions:

Graying of America

A term used to describe the demographic trend in the United States towards a larger proportion of the population being elderly, as a result of aging baby boomers and increased life expectancy.

Population Bomb

A term popularized in the late 20th century referring to the potential negative consequences of rapid population growth, including environmental degradation, resource depletion, and social unrest.

Paul Ehrlich

An American biologist and researcher known for his warnings about population growth and limited resources, and for his work in ecology and entomology.

Food Production

The process of creating food by farming, ranching, or fishing, encompassing everything from agricultural cultivation to livestock breeding.