Chapter 5 Lesson 5 "How Fungi Survive"

Materials:

• Worksheet, "Fungi"
• Worksheet, "Vocabulary Review"

Objective:

• Students will describe how fungi digest food.
• Students will explain asexual and sexual reproduction in fungi.
• Students will discuss the features of mycorrhizae and lichens.

Alaska Standards:

• SCI A-12 Students will distinguish the patterns of similarity and differences in the living world in order to understand the diversity of life and understand the theories that describe the importance of diversity for species and ecosystems.
• SCI A-15 Students will use science to understand and describe the local environment.

Anticipatory Set: Students will look at some pictures (picture 1, picture 2, picture 3) of Egyptian tombs. As they look at the pictures ask the question, "What do these tombs have to do with fungi? Then show the picture of a puffball as it discarges a cloud of its spores. Can these spores be harmful to humans as they breath the air? Have them look for a while and think back to the question about the tombs. Then pose the questions are there any molds that are harmful to humans? Some scientists suggest that high levels of mold spores breathed in by grave robbers led to their unexplained sickness and eventual death. This may be one of the reasons for the "curse" of the ancient tombs.

Once released, what happens to the spores? (The spores are carried by air currents, in water, or on the bodies of animals to new locations where they may grow into new fungi.)

Teacher Input: Ask if students know what Mutualism is? Explain the difinition of mutualism - A relationship between two different organisms in which both organisms benifit. Examples: (teacher, students/ horses, cowboys/ corn, farmers) Here is an example of three-way mutualism. The catapillar has necture glands that the ants feed on. The catapillar feeds on the flower and carries pollen from place to place for the plants reproduction. The ants provide protection for both the catapillar and the flower. There are thousands. Fungi form several mutualistic relationships with many organisms, most angiosperms and gymnosperms form mutually beneficial associations with fungi. The fungi hyphae help the plant absorb water and nutrients; in return, the fungus receives food (carbohydrates) from the photosynthesizing plant. Hyphae also help roots branch and aborb more nutrients.

Here is another mutualistic relationship. Lichen is actually two organisms growing together.Here are some pictures: lichen 1, lichen 2, lichen 3, Lichen 4. In this relationship, algal cells become so enmeshed in fungal hyphae that a new plant-like species are formed. The two organisms are so entwined that they are classified as a separate division in the kindom Fungi. Define Mycorrhiza, and Lichen:

Teacher Modeling: Explain the picture on P 107 (this should explain most of the section on "Getting and Digesting Food", While you do use the terms, mycelium, hyphae and digestive enzyme. Define digestive enzyme.

Check for Understanding: Explain the two types of reproduction here are the key points:

• When conditions are good reproduction is normally accomplished asexually.
• Two methods of asexual reproduction, releasing spores (usually a single cell that if it lands in favorable conditions it will produce a mycelium that looks like the original)Pic, and budding, part of a cell pinches off to form a smaller cell, the smaller cell grows quickly to form a cell the same size as the orginal, pic Define budding,
• When conditions are poor, many fungi can reproduce sexually. When plus and minus hyphea run into each other they combine and form a structure that produces spores that are different from either parent.

Closure: Pull the students attention to the reading on P 110 about bacteria that have the ability to use metals for an energy source.

Independent Practice: Student will work on the worksheets (vocab reveiw, and Fungi) for review, take the quiz on section 5 and then prepare for the test tomorrow.

Duration:

30 minutes + 10-15 for Independent Practice (Could be longer if taken for homework).