Bacteria

What does Tim mean when he says bacteria are the most abundant form of life on earth?

• They're the smallest form of life on earth.

• They're the most commonplace form of life on earth.

• They're the most diverse form of life on earth.

• They're the most specialized form of life on earth.

What do all bacteria have in common?

• They all have cell nuclei.

• They're all multi-cellular organisms.

• They're all single-celled organisms (unicellular).

• They can all be found inside the human body.

How did bacteria make complex life on Earth possible?

• By releasing oxygen into the atmosphere

• By destroying life-inhibiting volcanoes

• By evolving rapidly into multi-celled organisms

• All of the above

What might happen if you didn't have bacteria in your digestive tract?

• Your intestines would shut down

• Your body couldn't break down certain types of food

• You would never get sick

• You wouldn't be able to eat vegetables

Nitrogen-fixing bacteria help plants thrive. What do nitrogen-fixing bacteria do?

• Absorb harmful nitrogen from the bodies of plants

• Absorb nitrogen in the soil before it harms plants

• Convert nitrogen in the soil into a form that plants can absorb

• Transform nitrogen into carbon dioxide

Which of the following is a true statement about bacteria?

• Bacteria exist in only a few environments on earth.

• Bacteria can grow to extremely large sizes.

• Most bacteria are harmful to humans

• Bacteria can be both harmful and helpful to humans

What effect do antibiotics have on bacteria?

• They help bacteria grow in size

• They prevent bacteria from digesting food

• They destroy bacteria

• They help bacteria reproduce

Which of the following depicts one of the most common forms of bacteria?

• A

• B

• C

• D

What term best describes the function of flagella in bacteria?

• Locomotion

• Digestion

• Absorption

• Reproduction

How are bacterial cells different from plant and animal cells?

• Bacterial cells contain many more cell organelles.

• Bacterial cells contain almost no cell organelles.

• Bacterial cells have more complex cell organelles.

• Bacterial cells have well-defined nuclei.