Chapter 15: Parasitism and Mutualism

Question 1

Situation in which two dissimilar organisms live together in close association

Answer 1

symbiosis

Question 2

Diseased condition arising when pathogenic microorganisms enter a body, become established, and multiply

Answer 2

infection

Question 3

Any deviation from a normal state of health

Answer 3

disease

Question 4

Any of the viruses, bacteria, and protozoans, characterized by small size, short generation time, and rapid multiplication

Answer 4

microparasite

Question 5

Any of the parasitic worms, lice, fungi, and the like that have comparatively long generation times, spread by direct or indirect transmission, and may involve intermediate hosts or vectors

Answer 5

macroparasite

Question 6

A parasitic plant that contains chlorophyll and is therefore capable of photosynthesis

Answer 6

hemiparasite

Question 7

A parasitic plant that contains no chlorophyll and is therefore not capable of photosynthesis, as a result it cannot exist without a host plant

Answer 7

holoparasite

Question 8

Parasite, such as a flea, that lives in the fur, feathers, or skin of the host

Answer 8

ectoparasite

Question 9

Parasite that lives within the body of the host

Answer 9

endoparasite

Question 10

A form of feeding in which one animal appropriates food gathered by another (the host);

Parasitism by theft

Answer 10

kleptoparasitism

Question 11

Occurs when a parasite is transferred from one host to another without the involvement of an intermediate organism;

Can occur by direct contact with a carrier, or the parasite can be dispersed from one host to another through the air, water, or other substrate

Answer 11

direct transmission

Question 12

An intermediate organism that parasites depend on to be transmitted from one host to another (indirect transmission)

Answer 12

intermediate vector

Question 13

Host that harbors a developmental phase of a parasite;

The infective stage or stages can develop only when the parasite is independent of its definitive host

Answer 13

intermediate host

Question 14

A growth response to an alien substance in plant tissues

Answer 14

gall

Question 15

Host in which a parasite becomes an adult and reaches maturity

Answer 15

definitive host

Question 16

A range of adaptations that minimize the impact of parasites;

Hosts respond to parasitic infections through behavioral changes, inflammatory responses at the site of infection, and subsequent activation of their immune systems;

Includes grooming, behavior, inflammation, cyst, scab, gall

Answer 16

host responses

Question 17

Relationship between species that is beneficial to one, but neutral or of no benefit to the other

Answer 17

commensalism

Question 18

Relationship between two species in which both benefit

Answer 18

mutualism

Question 19

Plants that possess ant-attracting substances on their seed coats

Answer 19

myrmecochores

Question 20

Shiny, oil-containing, ant-attracting tissue on the seed coats of many plants

Answer 20

elaiosome

Question 21

A mutualist that cannot survive or reproduce without the mutualistic interaction

Answer 21

obligate mutualist

Question 22

A mutualist that can survive or reproduce without the mutualistic interaction

Answer 22

facultative mutualist

Question 23

Single-celled, symbiotic algae in the tissues of corals

Answer 23

zooxanthellae

Question 24

Describe the relationship that occurs within the reef-forming corals of the tropical waters

Answer 24

This is a type of symbiotic mutualism:

The symbiotic algae, zooxanthellae, provides 90% of the coral’s daily energy requirement from carbon produced through photosynthesis;

Without the algae, the corals would not be able to survive and flourish in their nutrient-poor environment;

In turn, the coral provides the algae with shelter and mineral nutrients, particularly nitrogen in the form of nitrogenous wastes

Question 25

Structures formed by plant root hair cells that have become swollen and infected due to the invasion and growth of rhizobia

Answer 25

root nodules

Question 26

Describe the relationship that occurs between plants and bacteria of the genus Rhizobium

Answer 26

This is a type of symbiotic mutualism:

Legumes (plant species such as clover, beans, and peas) attract rhizobia (nitrogen-fixing bacteria that cannot fix gaseous nitrogen while in a free-living state) by releasing exudates and enzymes from the roots;

After rhizobia invades the root hairs, root nodules are formed, and the rhizobia reduces gaseous nitrogen to ammonia;

The bacteria receive carbon and other resources from the host plant;

In turn, the bacteria contributes fixed nitrogen to the plant, allowing it to function and grow independently of the availability of mineral (inorganic) nitrogen in the soil

Question 27

An example is the relationship between plant roots and mycorrhizal fungi:

The fungi assist the plant with the uptake of nutrients and water from the soil;

In turn, the plant provides the fungi with carbon, a source of energy

Answer 27

nutrient transfer mutualism

Question 28

Type of fungi that grows within tree roots, and fungal hyphae enter the cells

Associated with the root systems of the vast majority of terrestrial plant species and are especially important in nutrient-poor soils;

They aid in the decomposition of dead organic matter and the uptake of water and nutrients, particularly nitrogen and phosphorus, from the soil into the root tissue

Answer 28

endomycorrhizae

Question 29

Mutualistic association associated with defense of the host organism;

Example between plant and fungi:
The fungi defend the host plant against grazing, whereas the plant provides food to the fungi in the form of photosynthates (products of photosynthesis)

Answer 29

defensive mutualism

Question 30

pollination

Answer 30

Because wind dispersal can be unreliable, pollen transfer typically depends on insects, birds, and bats;

Plants entice certain animals by color, fragrances, and odors, dusting them with pollen and then rewarding them with a rich source of food: sugar-rich nectar, protein-rich pollen, and fat-rich oils;

The nectivores inadvertently pick up pollen and carry it to the next plant they visit

Question 31

seed dispersal

Answer 31

check the book

Question 32

land use and malaria and Lyme disease

Answer 32

check the book