LECTURE Chapter 12 Overview: Eukaryotes
This chapter focuses on various eukaryotic organisms, including fungi, algae, protozoa, and
helminths. It ties into labs 16, 17, and 18, where you examined several of these organisms
microscopically.
Fungi
General Overview: Fungi belong to the kingdom Fungi and are chemoheterotrophs,
meaning they obtain energy from various elements.
Characteristics:
oMulticellular (except yeast, which is unicellular).
oAbsorb nutrients through their cell membranes.
oReproduce through sexual or asexual spores.
Comparison with Bacteria:
oAll fungi are eukaryotic and have sterols in their membranes.
oFungal cell walls are not made of peptidoglycan (unlike bacteria).
oFungi have a diverse metabolism but are not as diverse as bacteria.
oFungi can be aerobic or facultatively anaerobic.
Types of Fungi:
oMolds (multicellular): Have hyphae (stalks) and mycelium (the mass of hyphae).
oUnicellular fungi: Yeasts, which reproduce by budding or fission (e.g.,
Saccharomyces cerevisiae).
oDimorphic fungi: Can switch between a yeast form and a mold-like form,
depending on environmental conditions (e.g., Candida albicans).
Fungal Reproduction:
oAsexual reproduction: Involves the production of spores (e.g., conidia,
sporangia).
oSexual reproduction: Involves the fusion of two organisms, creating structures
like zygospores or ascospores.
oExample: The common mushroom represents sexual reproduction in fungi.
Medical Relevance:
oFungal infections can be classified into:
Systemic mycosis (deep in the body)
Subcutaneous mycosis (under the skin)
Cutaneous mycosis (affecting skin, hair, nails)
Superficial mycosis (localized, on the surface)
Opportunistic mycosis (occurs when the immune system is compromised
or after antibiotic use).
Algae
General Overview: Algae are part of the Protista kingdom, and they are
photoautotrophs, meaning they produce their own energy from sunlight and carbon
dioxide.
Characteristics:
