Biology 2EE3 - Chapter 17

Which of these is true of a mutualistic relationship?

Neither organism benefits or is harmed by the relationship.

One member benefits and the other member does not receive any benefit.

Both organisms benefit.

Both members are harmed from the relationship.

One member benefits and the other member is harmed.

c

Which of these is characteristic of the nitrogenase enzyme?

It requires hydrogen gas for activity.

It is found in all plant symbionts.

It is irreversibly inactivated by oxygen.

It is found in both prokaryotes and eukaryotes.

It converts dinitrogen to nitrate.

c

In order to make sufficient ATP for symbiotic nitrogen fixation, the plant supplies the symbionts with ____________ for energy production.

C4-dicarboxylic acids

fatty acids

C3 acids

NADH

glucose

a

The mycobiont of a lichen receives sugars from the photobiont as a benefit from this relationship while the photobiont receives _______________ from the mycobiont as a benefit.

amino acids

vitamins and amino acids

inorganic nutrients and protection from desiccation

protection from predation

ATP

c

What is the human microbiome composed of?

Microbes that contribute to the health of humans.

Microbes that live in the intestinal tract of humans.

All the microbes that cause disease in humans.

All microbes that live on or within the human body.

Microbes that live on human skin.

d

The majority of Archaea found in the human intestinal tract are _____ .

fermenters

sulfate-reducing bacteria

sulfide oxidizing bacteria

methanogens

halobacteria

d

Herbivores require microorganisms to help them with the digestion of this compound.

glycogen

nucleic acids

cellulose

starch

proteins

c

What is an endophyte?

A symbiont that lives inside plant cells.

A parasite of an animal.

A parasite of a plant.

A member of the plant root rhizosphere.

A member of the intestinal tract microbial community.

a

Once rhizobia enter the plant cell through the infection thread they undergo rapid multiplication and differentiation into pleomorphic nitrogen fixing cells called _____ .

reticulate forms

nitromorphs

shizonts

bacteroids

elementary bodies

d

The host-range specificity between specific legumes with specific rhizobia involves the transcriptional activation of the bacterial nod genes through the secretion of specific ___________ by the plant.

lactones

nucleotides

sugars

flavonoids

fatty acids

d

Which of these is TRUE of a lichen?

It is a type of slime mold.

It is comprised of a fungus and usually a green alga.

It is comprised of a fungus and an archaeal symbiont.

It is classified as a plant.

It is comprised of a protozoan and anarchaeal symbiont.

b

The most common inhabitants of the human skin are members of which phyla?

Firmicutes and Actinobacteria

Actinobacteria and Proteobacteria

Proteobacteria and Bacteroidetes

Proteobacteria and Firmicutes

Bacteroidetes and Firmicutes

a

Which of these is the MOST abundant bacterial group in the colon?

facultative anaerobes

members of the phylum Proteobacteria

the family Enterobacteriaceae

lactobacilli.

obligate anaerobes

e

Many of the rumen bacteria specialize in the breakdown of these macromolecules.

cellulose polymers

proteins

nucleic acids

fatty acids

peptidoglycans

a

The red color of plant root nodules is due to this oxygen binding protein.

leghemoglobin

flavoprotein

cytochrome c

nitrate reductase

menaquinone

a

The vagina of women of child-bearing age has an acidic pH. This is due to the colonization by which organisms?

lactobacilli

staphylococci

Candida sp

Bacteroides sp

micrococci

a

The majority of Archaea found in the human intestinal tract are _____ .

methanogens

fermenters

sulfide oxidizing bacteria

halobacteria

sulfate-reducing bacteria

a

Herbivores require microorganisms to help them with the digestion of this compound.

glycogen

nucleic acids

cellulose

starch

proteins

c