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Chapter 16 Varieties of Life: Fungi and Animals
CHAPTER OUTLINE
16.1 Fungi and animals are closely related kingdoms.
Knowledge of fungi and animals, increased because of additional data from DNA
sequencing, has added to our understanding of these organisms including that they appear
to be more closely related than previously thought.
16.2 Fungi have unique traits.
Fungi are multicellular eukaryotic organisms which must ingest food. Chytrids,
Zygomycota, Ascomycota, Basidiomycota and Fungi Imperfecti are the major groups of
fungi.
Fungi have simple-but-unusual body structures.
Filaments of hyphae make up the mycelium which produces a fruiting body during sexual
reproduction.
Fungi digest food externally and absorb nutrients.
Both fungi and animals must ingest food; fungi secrete digestive enzymes into the
environment and absorb nutrients. Many types of food, from dead to living organisms or
substances and parts left by organisms, are digested by fungi making them important
decomposers. Some fungal relationships are beneficial, including mycorrhizae and
plants.
Fungi have complex reproductive strategies.
Both asexual and sexual reproduction occurs in the fungal life cycles. Both types result
in spore formation and release. The major groups of fungi are divided by sexual
reproduction type with Fungi Imperfecti made up of types in which sexual reproduction
has not been observed.
16.3 Fungi are the ultimate recyclers and other organisms use them for food.
Fungi are adapted to diverse environments, traveling easily via spores.
Humans and other species also use fungi as a food source.
Many organisms, including humans, eat fungi.
Fermentation by fungi produces alcohol and carbon dioxide.
Humans use fungi to ferment food sources producing bread, alcohol and cheese.
Fungi are used for medicines.
It was discovered that fungi produce a chemical which affects bacterial growth, now used
by humans as antibiotics.
16.4 Animals are adapted to many environments.
DNA evidence has supported much of the established classifications in the animal
kingdom but has also revealed new information. Animals are multicellular eukaryotes
which must ingest food. Animals are adapted to many habitats.
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Living animals exhibit just a few basic body plans.
The simplest organisms have one opening to their digestive cavity while more complex
organisms have a tube-in-a-tube body plan which includes a mouth and anus. Additional
characteristics used to categorize animals are symmetry, radial or bilateral, and number of
embryonic layers; ectoderm, mesoderm and endoderm. Animals with bilateral symmetry
have body areas which can be identified as anterior, posterior, ventral and dorsal.
Bilateral symmetry leads to increased complexity which includes the presence of limbs
and a nervous system.
Animals have diverse adaptations for obtaining food.
Included in the animal kingdom are filter feeders, grazers, browsers and predators.
Animals have diverse reproductive strategies.
Eggs and sperm are produced by animals and the way each parent provides these gametes
for sexual reproduction is diverse. Hermaphrodites have both male and female sexual
organs and so produce both eggs and sperm. Some organisms such as in the Cnidaria
have a complex life cycle which involves two life forms while many arthropods undergo
metamorphosis. Some animals invest a great deal of time and energy in developing
offspring.
16.5 Animal parasites can make humans and other animals sick.
Parasites are prevalent within all ecosystems, causing disease in animals. Some animals
are disease vectors, carrying pathogens to other animals.
16.6 Fungi and animals have long evolutionary history.
Fossil and DNA evidence has revealed the evolutionary history of fungi and animals. A
specific example of animal evolution is mammalian evolution; present day mammals
reflecting this are the monotremes, marsupials and placentals.
Humans evolved in Africa.
Fossil and DNA evidence show that humans first appeared in Africa.
16.7 How do you know? What happened in Salem 1692?
Historical information leads scientists to conclude that the Salem witch frenzy may have
been the result of ergot poisoning in a common food source.
Now you can understand.
Anti-fungal drugs work by targeting specific molecules found in fungal cell walls and
membranes.
What do you think?
A discussion of 'Big Foot' and 'little people' is presented to show how some information
is from myth and some may be derived from facts and the importance of discovering
which is which.
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