Heterotrophic Nutrition

Page
5

Slide 33

The fungus helps the host plant absorb inorganic nitrogen and phosphorus from the soil. Some mycorrhizal fungi also secrete antibiotics which may help protect their host from invasion by parasitic fungi and bacteria.

Symbiosis

Slide 34

Many mushrooms are the spore-forming bodies of mycorrhizal fungi. The truffle [View] is often found in oak forests because the fungus that produces it establishes mycorrhiza on oak roots.

Symbiosis

Slide 35

Parasitism

A parasite is an organism that

lives on or in the body of another organism (the host)

from whose tissues it gets its nourishment, and

to whom it does some damage

Symbiosis

Slide 36

"hit and run" parasites that live in their host for a brief period and then move on to another with or without killing the first to

parasites that establish chronic infections. Both parasite and host must evolve to ensure the survival of both because if the parasite kills its host before it can move on, it destroys its own meal ticket.

Link to further discussion.

Symbiosis

Slide 37

Animals are parasitized by viruses, bacteria, fungi, protozoans, flatworms (tapeworms and flukes), nematodes, insects (fleas, lice), and arachnids (mites).

Plants are parasitized by viruses, bacteria, fungi, nematodes, and a few other plants.

Parasites damage their host in two major ways:

consuming its tissues, e.g., hookworms

Symbiosis

Slide 38

Commensalism

A symbiotic relationship in which one species benefits and the other is not affected. www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookglossC.html

Commensalism is a situation in which two organisms are associated in a relationship in which one benefits from the relationship and the other is not affected much. The two animals are called commensals. An example pf commensalism is vermiliads (plants living on trees in rainforests) and frogs; the frogs get shelter and water from the vermiliad but the vermiliad is unaffected. Commensalism is a type of symbiosis. COMPANION CELL A companion cell is a type of cell that pumps nutrients (sugars) into phloem cells. www.enchantedlearning.com/subjects/plants/glossary/indexc.shtml

When two organisms coexist, one organism benefits, the other is not affected. www.alken-murray.com/glossarybug.html

Symbiosis

Slide 39