Life: The Science of Biology

David Sadava, David M. Hills, H. Craig Heller

Chapter 30

The Evolution and Diversity of Fungi - all with Video Answers

Educators

Chapter Questions

Problem 1

The absorptive heterotrophy of fungi is aided by
a. dikaryon formation.
b. spore formation.
c. the fact that they are all parasites.
d. their large surface area-to-volume ratio.
e. their possession of chloroplasts.

Dr. Bridgette Drummond

Dr. Bridgette Drummond

Numerade Educator

Problem 2

Which of the following is a reason that lichens can be useful indicators of environmental change?
a. Lichens excrete the toxic substances that they absorb, and these excretions can be used to measure local contamination.
b. Because lichens retain toxins, historical collections of lichens can be used to measure past atmospheric conditions.
c. Atmospheric pollutants (such as $^{206} \mathrm{Pb}$ ) stimulate lichen growth, so heavy lichen growth is a sign of air pollution.
d. Atmospheric pollution stimulates mycorrhizal activity, which inhibits lichen growth.
e. None of the above

Dr. Bridgette Drummond

Dr. Bridgette Drummond

Numerade Educator

Problem 3

Which statement about the dikaryon stage is not true?
a. The cytoplasm of two cells fuses before their nuclei fuse.
b. The two haploid nuclei are genetically different.
c. The two nuclei are of the same mating type.
d. The dikaryon stage ends when the two nuclei fuse.
e. Not all fungi have a dikaryon stage.

Dr. Bridgette Drummond

Dr. Bridgette Drummond

Numerade Educator

Problem 4

Microsporidia
a. lack true mitochondria.
b. are parasites of animals.
c. contain mitosomes.
d. are among the smallest eukaryotes known.
e. All of the above

Dr. Bridgette Drummond

Dr. Bridgette Drummond

Numerade Educator

Problem 5

Which statement about lichens is not true?
a. They can reproduce by fragmentation of the vegetative body.
b. They are often the first colonists in a new area.
c. They render their environment more basic (alkaline).
d. They contribute to soil formation.
e. They may contain less than 10 percent water by weight.

Dr. Bridgette Drummond

Dr. Bridgette Drummond

Numerade Educator

Problem 6

You are shown an object that looks superficially like a pale green mushroom. Describe at least three criteria (including anatomical and chemical traits) that would enable you to tell whether the object is a piece of a plant or a piece of a fungus.

Dr. Bridgette Drummond

Dr. Bridgette Drummond

Numerade Educator

Problem 7

Many fungi are dikaryotic during part of their life cycle. Why are dikaryons described as $n+n$ instead of $2 n ?$

Dr. Bridgette Drummond

Dr. Bridgette Drummond

Numerade Educator

Problem 8

If all the fungi on Earth were suddenly to die, how would the surviving organisms be affected?

Dr. Bridgette Drummond

Dr. Bridgette Drummond

Numerade Educator

Problem 9

Consider the following data for lichens at five survey sites:
$$\begin{array}{ccc}
\hline \begin{array}{l}
\text { Site } \\
\text { number }
\end{array} & \begin{array}{c}
\text { Number of } \\
\text { lichen species }
\end{array} & \begin{array}{c}
\text { Tree branches covered } \\
\text { in lichens (\%) }
\end{array} \\
\hline 1 & 5 & 38 \\
2 & 1 & 2 \\
3 & 3 & 15 \\
4 & 8 & 75 \\
5 & 13 & 100 \\
\hline
\end{array}$$
Predict the relative order of the sites with respect to their distance from the center of a large city. Other factors (besides distance to city center, such as prevailing wind direction) might affect your prediction. Can you think of two other major factors that might influence these results?

Dr. Bridgette Drummond

Dr. Bridgette Drummond

Numerade Educator

Problem 10

When biologists isolate DNA from whole-plant samples to study plant genomes, the investigators sometimes find that some of the genes they isolate appear to be more closely related to fungal genes than they are to the genes of close relatives of the plants they are studying. What is a likely explanation of this observation? How could you test your hypothesis?

Dr. Bridgette Drummond

Dr. Bridgette Drummond

Numerade Educator