Ch12 study guide BIO205

• 1. Most of DNA is packaged with histone proteins as chromosomes in the form of chromatin fibers located within nuclei.
• 2. Eukaryotes have a variety of methods of asexual reproduction, including binary fission, budding , fragmentation, spore formation
• 3. many eukaryotes reproduce sexually- involves the formation of sexual cells called gametes
• 4. additionally algae, fungi, and some protozoa reproduce both sexually and asexually 

2 sets of chromosomes (4 haploid cells)

• 1 set of chromosomes
• •Mostfungi, many algae, and some protozoa are haploid; the rest are diploid

nuclear division results into two nuclei

nuclear division of diploid eukaryotic cells resulting in four haploid nuclei

cytoplasmic division

multinucleate cells resulting from repeated mitosis

special type of asexual reproduction in which the protozoan Plasmodium undergoes multiple mitoses to form multinucleate schizont

• moist environments
• Ponds,lakes, streams, oceans – some are plankton 
• -basis of aquatic food chain
• Also found in moist soil, beach sand, and decaying organic matter

• Some ciliates have 2 nuclei 
• •may contain as many as 50 copies of genome

all free-living aquatic and pathogenic protozoa exist a s a Motile feeding stage is a trophozoite

hardy resting stage of some protozoa is a cyst

–phagocytize bacteria, decaying organic matter, other protozoa, or tissues of host

• •Dinoflagellates and euglenids
• algal plants

• -Parabasala- Lack mitochondria!!
• –Trichonympha-Helps digest wood in guts of termites
• –Trichomonas
• - sexually transmitted
• •Vaginal infections
• •Can cause sterility

• Diplomonadida Lack mitochondria, Golgi bodies and peroxisomes
• Have 2 equal-sized nuclei and multiple flagella
• •Giardia – a diarrhea-causing pathogen of humans found in steams, etc.
• •Make cysts which humans                              
• and pets ingest from streams

• Euglenids
• •Characteristics of both plants and animals
• •Photoautotrophic, chlorophyll, no starch
• •Lack cell walls, have flagella
• •Trypanosoma and Leishmania
• •Bothcause potentially fatal diseases of humans carried by flies

• Alveolates –contain alveoli, 3 subgroups
• Balantidium (the only ciliate pathogenic to humans
• Apicomplexans – all pathogens
• •Plasmodium (causes malaria)
• •Pfiesteria- neurotoxin in fish, poisons by      handling infected fish or breathing air                                 with microbes

• unicellular Amoebae that use threadlike pseudopodia
• •Foraminifera – porous shell of calcium carbonate Form limestone hundreds of meters thick
• •Radiolarians – shell of silica

• Amoebozoa–Lobe-shaped pseudopodia, no shell
• Maycause diseases of swimmers
• Naegleria and acanthamoeba –infects brains, eyes 
• Slime Molds –lack celle walls, phagocytic

• decompose dead organisms and recycle their nutrients
• humans use for foods
• produce antibiotics
• research in study
• not beneficial mycoses fungal disease

small, blobullar, single cells

eiher septate or aseptate

large and composed of long branched tubular filaments called hyphae

fungi that produce two type of thalli

vegetative body of a fungus

• •Secretecatabolic enzymes to break down large, organic molecules
• •Mostare saprobes - absorb nutrients from dead organisms

•most are aerobic, yeasts are facultative anaerobes; some anaerobic fungi are found in digestive tract of cattle and deer

•All fungi reproduce asexually; most fungi also reproduce sexually

• –Yeasts typically bud – Candida albicans invades human tissue by means of pseudohyphae
• – long chains of budded cells – causes thrush and vaginal infections

• –Sporangiospores •Form inside a sac – sporangium
• –Chlamydospores •Form with thickened wall                                     inside hyphae
• –Conidiospores •Produced a tips of hyphae,                                           but not within a sac

• 1.Zygomycota (black bread mold, Microsporidia)
• 2. Ascomycota formation og haplouid (Aspergillus, Penicillium, Saccharomyces, truffles)
• 3. Basidiomycota (mushrooms, Cryptococcus neoformans

•Partnership between fungi and photosynthetic microbes

•Most are aquatic, but also live in soil, ice, in lichens

•Can be unicellular, colonial or multicellular (seaweeds)

• red- kingdom rhodophyta cell walls of agar
• green- chlorophyta plants
• brown- phaeophyta stramenopila
• yellow- green, golden, diatoms: chrysophyta diverse with respect to cell walls composition and pigments

• •Not fungi – related to algae
• •Decompose dead animals
• •cell wall of cellulose

• –Parasiticworms
• Microbiologists
• usually identify the microscopic eggs or cysts
• –Arthropod vectors •Mechanical
• vectors –Just carry the pathogen from place to place
• •Biological vectors Serve as hosts for the pathogen

• •4 pairs of legs
• –Ticks and mites (chiggers)
• –Ticks are the more important arachnid carriers - carry bacterial, viral and protozoan
• diseases
• •Lyme disease, Rocky Mountain spotted fever, tularemia, encephalitis

• •3pairs of legs
• –Fleas– carry the plague on rodents
• –Lice– involved in typhus epidemics
• –Flies– tsetse flies carry African sleeping sickness
• –Mosquitoes – most important arthropod vectors of disease
• •Malaria, yellow fever, dengue fever, viral encephalitis 
• Kissingbugs – Chagas’ diseas caused by a protozoan