Bio 1.2.3 Unicellular Organisms

Which of the following is a typical example of a unicellular organism?

• earthworm

• bacteria

• fungi

• green algae

Which example represents chemotaxis?

• An amoeba engulfs a food particle.

• A paramecium removes excess water.

• A euglena moves from a dark area towards a light source.

• A bacterium swims towards higher concentrations of glucose.

How are flagella and cilia similar?

• They both aid in movement.

• They are both used for reproducing.

• They are both hair-like projections that are used for digestion.

• They are both used to shoot out trichocysts that paralyze potential prey.

Which helps a paramecium maintain homeostasis in aquatic environments?

• contractile vacuole

• macronucleus

• mitochondria

• eye spot

Phototaxis is movement in response to which stimulus?

• light

• sugar

• chemicals

• nutrients

To maintain homeostasis, a cell needs to expel some of its water. Which structures below would most likely help accomplish this task?

• pseudopods

• protein pumps

• tunnel proteins

• contractile vacuoles

Freshwater protists have a contractile vacuole that saltwater protists lack. What is the best explanation for this?

• The saltwater protists cannot make their own food.

• The saltwater protists use a flagellum to move instead.

• The freshwater protists evolved after the saltwater protists.

• Freshwater protists must keep a balance of water to maintain homeostasis.

What structure in bacteria protects the cell from injury and resists some antibiotics?

• nucleus

• cell wall

• mitochondria

• cell membrane

What primary function do flagella serve in bacteria?

• gathering food

• intake of fluids

• directional movement

• defense against attackers

Which is a primary function of a cilium?

• movement

• catching prey

• sensing light

• maintaining homeostasis