Ch 15

There are _______ major domains, which are determined by molecular evidence.

• two

• three

• four

• five

• six

The most fundamental groups of organisms on the planet are:

• plants, animals, and bacteria.

• plants, animals, and eukarya.

• bacteria, animals, plants, and eukarya.

• bacteria, archaea, and eukarya.

• bacteria, archaea, and protista.

Which of these is a false statement about microbes?

• Microbes can be one thousand billion trillion times smaller than a human.

• Microbes lack the distinct body systems that humans have.

• Microbes are not genetically diverse.

• Microbes cause all of the diseases in the human.

• Microbes are the most abundant organism on earth.

Human beings:

• contain more human cells than microbial cells.

• contain more protist cells than bacterial cells.

• contain more microbial cells than human cells.

• are more closely related to viruses than to their siblings.

• are more closely related to bacteria than archaea.

Spherical bacteria are known as:

• cocci.

• bacilli.

• spirilla.

• Gram-positive.

• Gram-negative.

Which of these is not contained in a bacterium?

• ribosomes

• mitochondria

• DNA

• cytoplasm

• plasma membrane

Which statement about prokaryotes is false?

• Prokaryotes contain ribosomes.

• Some prokaryotes can conduct photosynthesis.

• Prokaryotes have circular pieces of DNA within their nuclei.

• Prokaryotes appeared on earth before eukaryotes.

• Prokaryotes contain cytoplasm.

Which of these would not be found in prokaryotic cells?

• photosynthetic pigments

• flagella

• a peptidoglycan cell wall

• ribosomes

• membrane-bound nucleus

A bacterium is Gram-positive only if it:

• has a layer of peptidoglycan on the outside of the cell wall.

• has a layer of glycoproteins beneath the cell wall.

• maintains its natural color when dye is added.

• has no pili on its outermost surface.

• has a layer of cytoplasm on the outside of the cell wall.

A bacteriophage is a:

• bacterium that eats other bacteria.

• protist that eats bacteria.

• specialized white blood cell that attacks bacteria in an immune system defense.

• virus that infects bacteria.

• bacterium that eats mammalian red blood cells.