Question 1

Some fungi are predators (not parasites)of:

Accepted Answer

Some fungi are known to be predators of nematodes (roundworms), which they capture and digest using specialized trapping structures. This is a form of carnivory and not parasitism, as the fungi do not rely on living on the nematodes for sustenance.

Question 2

Which of the following features are characteristic of fungi?

Accepted Answer

Fungi have cell walls, feed by absorption, and usually have filamentous bodies. Photosynthesis and chemosynthesis are not characteristic of fungi, and fungi are not typically parasitic.

Question 3

The mat-like structure composed of hyphal threads that forms the body of most fungi is called a(n):

Accepted Answer

The mycelium is the mat-like structure composed of hyphal threads that forms the body of most fungi. A) An ascus is a sac-like structure that contains spores in some fungi. B) A septum is a cross-wall that divides hyphae in some fungi. D) A zygospore is a structure formed by the union of two gametangia in some fungi. E) A basidium is a club-shaped structure that produces spores in some fungi.

Question 4

The interwoven mass of cells that forms large structures like an earthstar or a mushroom is a:

Accepted Answer

The interwoven mass of cells that forms large structures like an earthstar or a mushroom is known as mycelium. Mycelium is made up of thread-like structures called hyphae, which intertwine and spread through the substrate to absorb nutrients.

Question 5

The worldwide die-off of frogs has been traced to infection by:

Accepted Answer

The worldwide die-off of frogs has been traced to infection by chytrids, specifically Batrachochytrium dendrobatidis (Bd). This fungal pathogen infects the skin of amphibians, causing them to become too weak to breathe or regulate their electrolyte and water balance, eventually causing death.

Question 6

Based on the fossil record, the oldest fungi were:

Accepted Answer

The fossil record suggests that the oldest known fungi were chytrids, dating back to 1 billion years ago.

Question 7

Fungal cell walls are different from plant cell walls because fungal walls contain:

Accepted Answer

Fungal cell walls contain chitin, while plant cell walls contain cellulose.

Question 8

Fungi are similar to plants because both:

Accepted Answer

Fungi and plants both have cell walls surrounding their plasma membranes. However, plants have cellulose cell walls while fungi have chitin cell walls. The other options are not accurate for both fungi and plants.

Question 9

In which environment would you most likely find chytrids?

Accepted Answer

Chytrids are aquatic fungi and are commonly found in wet environments such as lakes, rivers, and swamps.

Question 10

Which fungal group produces swimming, flagellated spores?

Accepted Answer

Chytrids produce swimming, flagellated spores called zoospores, which are unique among the fungal groups.

Question 11

Both bacteria and fungi digest food by:

Accepted Answer

Both bacteria and fungi secrete enzymes that break down large molecules in food into smaller molecules that can be absorbed through their cell walls. This process is called extracellular digestion.

Question 12

The dominant generation in the fungal life cycle is usually:

Accepted Answer

In the fungal life cycle, the dominant generation is usually the haploid stage. This is because after the fusion of gametes to form a diploid zygote, the zygote undergoes meiosis to produce haploid spores, which then grow into the dominant haploid stage. This haploid stage may be multicellular or unicellular, depending on the type of fungus.

Question 13

Fungi usually obtain food by:

Accepted Answer

Fungi secrete enzymes that break down organic matter externally and then absorb the resulting nutrients. This is known as extracellular digestion.

Question 14

According to the fossil record, the most ancient group of fungi is probably the:

Accepted Answer

The chytrids are believed to be the most ancient group of fungi based on fossil evidence, dating back around 500 million years.

Question 15

A zygosporangium is produced by:

Accepted Answer

A zygosporangium is formed through the union of two haploid hyphae.

Question 16

Molds easily contaminate foods because fungi:

Accepted Answer

Fungi produce huge numbers of highly mobile, airborne spores that can easily spread and contaminate nearby foods, even if the source of the mold is removed. This is why it is important to discard any food items that show signs of mold growth. The other options (A, C, D, and E) are not true or relevant in this context.

Question 17

When you eat mushrooms on your pizza, you are technically eating the:

Accepted Answer

Mushroom on pizza is the fruiting body of the fungus, and the actual organism that produces it is the mycelium, a web-like structure that runs through the soil or decaying matter. So, when you eat mushrooms on your pizza, you are technically eating the mycelium.

Question 18

Which of the following sequences describes sexual reproduction in the fungal life cycle?

Accepted Answer

Fungi have a complex life cycle that involves both sexual and asexual reproduction. In the sexual reproduction of fungi, haploid spores are produced by meiosis from a diploid zygote. These haploid spores then germinate and grow into haploid mycelia through mitosis. The haploid mycelia can then undergo sexual reproduction by fusing with another haploid mycelium of the opposite mating type to form a diploid zygote, which then undergoes meiosis to produce haploid spores. This cycle continues. Choice B best describes this sequence of events.

Question 19

The body of a fungus is generally composed of:

Accepted Answer

The body of a fungus is generally composed of hyphae, which are thread-like structures made of cells that are responsible for absorbing nutrients and providing structural support. Fungi do not have cellulose, vascular tissue, mycorrhizae, or mold as their main component.

Question 20

Which polysaccharide is produced by both fungi and arthropods?

Accepted Answer

Chitin is a polysaccharide that is produced by both fungi and arthropods. It is a structural component of the exoskeleton of arthropods and the cell walls of fungi. Cellulose is a polysaccharide found in the cell walls of plants, glycogen is a polysaccharide used for energy storage in animals, and glucose and fructose are monosaccharides used for energy.

Quiz 22: The Diversity of Fungi

Some fungi are predators (not parasites) of: