Biology II Week 8

The following statements describe something about the body structures or functions of fungi. Identify those statements that are correct.

All fungi are heterotrophs; some species live as decomposers and others as symbionts. Some fungi can grow as either filamentous or single-celled forms. Mycelia are made up of small-diameter hyphae that form an interwoven mass, providing more surface area for nutrient absorption. Some fungi secrete digestive enzymes into the environment and then absorb the digested nutrients.

Sort the following fungi based on whether they are decomposers, mutualists, or parasites.

DECOMPOSER: fungi in association with a fallen log fungi in association with a dead rabbit coprophilous fungi MUTUALIST: mycorrhizal fungi on pine tree roots fungi in the family Lepiotaceae PARASITE: Septobasidium spp. and an individual scale insect infected by fungal hyphae Cordyceps. spp. Trichophyton spp. Cryphonectria parasitica

If you wanted to use fungi to improve the environment, which of the following research goals would make the most sense?

Discover the lignin-digesting enzymes of fungi, and use them to digest plant tissues left over from food-crop residues to reduce landfill waste.

True or false? In most fungi, fertilization is complete after the cells fuse together.

FALSE

Fungi form mutualistic relationships with plants and animals; which of the following statements is an example of such a relationship?

Fungi help break down wood in the guts of termites. Fungi can help increase drought tolerance in plants. Endophytes in leaves produce toxins that deter herbivores. Fungi help break down plant material in the guts of grazing mammals.

Choose the correct body structure of the fungus

Only portions of the fungus have extended from the outer surface of its victim. We can infer that these projections are connected to an extensive network of hyphae that penetrate the wasp's body.

True or false? Most of the cells in a mushroom contain haploid nuclei.

TRUE

Drag the labels to their appropriate locations on the diagram of the fungus and hyphae

The body of a multicellular fungus consists of a network of hyphae, which form an interwoven mass called a mycelium. Some hyphae, called septate hyphae, are divided into cells by crosswalls, or septa. Coenocytic hyphae do not have septa; these hyphae consist of a continuous cytoplasmic mass that contains many nuclei and organelles.

Choose the correct ecological role of the fungus.

The fungus harms its host (in this case, killing it) and hence may cause the wasp population to decrease in size.

This wasp is the unfortunate victim of an entomopathogenic fungus (a parasitic fungus of insects). What does this image illustrate about the nutritional mode, body structure, and ecological role of the fungus?

The fungus secretes enzymes that break down the complex molecules of the wasp's body. The high surface-to-volume ratio of hyphal filaments makes absorption of the resulting smaller molecules highly efficient. The fungus is a heterotroph that acquires nutrients by absorption.

Where does meiosis occur in a mushroom?

basidia

Which of the following events occurs first in the development of a spore into a mature mushroom?

hyphae are produced by mitosis

Which structure allows the growing mushroom to nourish itself?

mycelium

Which structure is not directly involved in the reproduction of at least one major group of fungi?

mycelium

Which term describes the fusion of cytoplasm from two individuals?

plasmogamy

Which of the following statements describes the relationship between a fungus and a photosynthetic microorganism in a lichen?

the fungus provides the photosynthetic microorganism a suitable environment for growth