Dictyostelium Discoideum Straddles the Boundary Between Unicellular and Multicellular

question 121

Multiple Choice

Dictyostelium discoideum straddles the boundary between unicellular and multicellular.Its feeding phase consists of individual amoeba-like cells that move independently,feeding on bacteria.When the food runs out,cells begin to aggregate into a multicelled structure.The cells differentiate into a base,stalk,and spores;only the spores survive to colonize a new habitat.Dictyostelium discoideum is which of the following?

• A)a protozoan
• B)an apicomplexan
• C)an alga
• D)a diatom
• E)a slime mold

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Definitions:

Grasses

A large and diverse family of plants, known scientifically as Poaceae, which includes wheat, corn, and rice, and is characterized by narrow leaves growing from the base.

Synapsids

A group of animals that includes mammals and their extinct relatives, characterized by a single temporal fenestra (an opening in the skull behind each eye).

Reptiles

Cold-blooded vertebrates characterized by scales or hard plates, such as snakes, turtles, and lizards, that reproduce mostly through eggs.

Modern-Day Mammals

Contemporary species of the mammalian class, characterized by features such as hair, three middle ear bones, and mammary glands for feeding young.